This content provides a detailed overview of electric vehicle (EV) components, focusing on inverters and electric motors, particularly Brushless DC (BLDC) motors, and their operational principles, control mechanisms, and applications within EVs.
Mind Map
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Yes,
good afternoon to you all.
I welcome you all for the session.
So today morning you might have had a
demo session for the past two sessions
you had some kind demo righting
your uh whatever we have seen in the
last few classes that is uh chopper
rectifier and inverter right so these
are the things uh we were disclosing in
the previous session
uh now you can see right so this is the
entire block of your electric vehicle
and And as I said as I disclosed my
session in the before two sessions here
uh we are looking after this uh unit and
uh we have also saw about this unit like
power module and this buck and boost
these things we have completed. So now
we have to go in for our uh motor drive
right. So when you all uh again I'm just
uh plubbing these points up right. we
have to
take the inputs from every session and
then we have to give it for microcontroller
microcontroller
uh during yesterday's afternoon session
uh I think uh few of them asked like we
are into microcontroller we need to know
something about these things so I'll
just connect that point see here this is
a microcontroller studying about that
microcontroller and inside those things
and how to coding it will be in the last
uh like Friday session so for that you
need to know about what are the inputs
has to be taken. So if you're writing if
you're going to write a code into this
microcontroller right you have to know
like how these connected points are
working right so if you if you are
getting a signal into it you have to
process that signal and you have to give
it back to some other point so what type
of signal you are going to get how you
can process it and you are going to give
it to some other point say for example
you are just taking the input from this
module power stage right and you are
synthesizing it and After that you are
just feeding it to again motor or you
are taking feedback from motor you are
synthesizing it and then again feeding
back it to IGBT power model. This
requires how these parameters are
getting worked. Right? So these things
only we have seen in this few classes.
Right? So I'm continuing with this
session with this brief introduction. Uh
so I find some some more students has to
join. They are giving an information
like some more students has to join.
just I'll give some two to five minutes
time and uh if not we'll continue the
session. Yeah,
because we have to cover our own topics
So I think most of them have joined. So
I'm just uh again starting my session.
So yes, so you might have studied about
those uh inverters and you saw the demo
and these things right in that demo uh
the one point uh morning session was
covered was a multi-level inverter. So
basically we didn't go into that
multi-level inverter since I didn't have
an option of switching over the screens.
I didn't touch over that point uh in the
morning. So I thought like let it go as
a simulation itself. But anyway I'll
just touch around this uh multi-level
inverter and then we will go into that
motor drive right as planned. So if you
check with an inverter the output of the
inverter as this point that is total
harmonic distortion tsd. Okay actually
that actually tells like how much
unwanted signal is present inside the
converted signal. Say for example what I
can say is that you can uh simply say
this uh THD in such a way like your DC
is being converted as AC into the output
terminal. Correct? THD is nothing but
the certain signal that will not be
converted that that is not being
converted as AC signal will be present
in the at the output. So that signals
may be called as total harmonic
distortion that are nothing but the
disturbances or unwanted signal present
at the output point of the signal. So
this thing has to be maintained in one
standard. Say for example it will be
like this. So you have a sinosidal
waveform. This has been from this pulse
you are converting this cinosidal
waveform. Right? So if you see here this
is the harmonic of sinosidal voltage you
have certain harmonics here. See here
after this you in the fundamental only
you'll be having this much after that
you will not be having any THD. But if
you see a pulse you'll be having THD
like this at every instant right this is
harmonics okay this has to be minimized
if this is not this is maximus right
then what is the meaning is at that
output if you measure the voltage
through you can take it in this way if
you are measuring a voltage through
multimeter or any meter at that output
it will give the necessary output as a
numeric but if you see the waveform it
will not be a proper sinosidal waveform.
So that is the meaning of you are having
T if you are having a THD means that is
the meaning you are not getting a proper
sinosidal waveform at the output but
anyhow if you check with the value
you'll be able to get the value of the
available AC are you getting this point clearly
Yes. So very simple if you you you are
converting one DC signal to AC signal
right that AC signal has to come like 12
volt means if you measure through
multimeter it will you will be getting
12 volt but through oscilloscope if you
see that waveform that will not be
actually that will not be actually a
sinosidal waveform that is not actually
useful for your output also see if you
are going to operate any application
right it will it will all if you are
testing through multimeter means it is
good but if you are running any
application through to that out output
waveform that will not work properly. So
we should not have the total
harmonization at our output. Okay. So
what we have to according to it standard
what you can have is 5 percentage of THD
is allowed. Actually I cannot tell it is
5%age because for the according to the
output of output wtage the THD
percentage is varied. So maximum you can
go up to TH uh 5%. So 5%age of THD is
allowed. That means what? From your
fundamental voltage 5% is allowed. After
above that the THD% should not be
allowed. If it is there then it is
considered that that is not a pure
cinosidal waveform. So this should be a
very very important point for that only
we are actually using what this THD is
actually calculated like this only VRMS
without fundamental and VRMS
fundamental. Fundamental means your basic
basic
50 Hz uh sinosidal waveform and the uh
without fundamental means just avoid
that and other than that you'll be
having continuous sign waveform that is
the thing you have some first order
second order third order fourth order
fifth order even order harmonics that is
actually a big topic I'm just giving you
a glimpse that harmonics will have first
fundamental and then first order second
order third order four fourth order like
that in that if you see the even order
harmonics will not give significant at
that output but the odd order harmonics
will affect the output. So third, fifth,
seventh. Okay. So this is a huge topic
we need not go into that as of uh as of
a glimpse of knowledge what you can
understand is that your waveform should
not have TH ma more than 5%age of your
fundamental. So that is the thing. Now
how to minimize it? So for minimizing
this only what we can understand is that
towards that waveform in the morning
sessions you saw they were doing certain
things to make the waveform pure
sinosidal. Okay in that only we have
pulse with modulation techniques also
you are making more samples and we are
creating more number of levels within
one particular cycle. Is that clear? So
for that only we use pulse with
modulation technique and all. Apart from
that we are using another thing that is
called as multi-level inverters. Okay.
So the multi-level inverters are
uniquely suited for this application
because of the high voltage per ampere
rating with possible inverter level. If
you take normal two-level high frequency
pulse with modulation inverters for
automotive drive their problems are
associated with high voltage ranges.
High voltage ranges. Okay. Whereas if
you see here multi-level voltage source
inverters it structure by by itself
allows them to operate under to reach
the high voltages and power levels.
Okay, without the use of transformer
that means what? If you want to get an
output voltage of higher range okay if
you want if you want to get a voltage
output of higher range you need not use
pulse with modulation technique. Instead
what you can go is that you can go with
multi-level inverters also.
Right? So if you are using pulse with
modulation technique what you are what
you will be able to do is that you
cannot increase the voltage level. Okay.
What you can do is you can you can have
a incre voltage level in that level only
you can increase more uh number of
sample rates where but in the case of
multi-level inverter you can increase
the power output voltage ranges also. So
that is the advantage of moving from
using of multi-level inverter and
moreover this multi-level inverters can
easily provide the high power that is
required for large EVs and hybrid drive
vehicles. For example, in Volvo buses,
electric buses, they you are utilizing
this multi-level inverter. If you use
this multi-level inverter right you will
not you will be having le less THD that
is harmonic distortion will be very less
because you are using that much level of
power output individually. So I will I
will show show it through a circuit
you'll understand much more better. So
see here this is one level of output.
This is our laboratory level of uh
checking circuit. So here is our
oscilloscope. Here you can see the
transformer. These are three level 1 2 3
three level of inverter we are clubbing
it together. This is here you can see
the arino board. So through the arino
board we are just giving the program
like how it has to be pulses are given
through drive circuit. So through pulses
we are just giving it and we are making
this inverter to work. Right now if you
could see
this is the these are the different
types of multi-level inverters. Flying
capacitor, diode clamp inverter, hybrid
inverter, cascaded Hbridgeidge inverter.
In this cast Hbridgeidge inverter, you
have symmetrical and asymmetrical.
Generally for automotive application,
we'll be using this cascaded Hbridgeidge inverter.
inverter.
So if you see this cascaded Hbridgeidge
inverter, right? So this is a here I
have shown a 11 level. Okay? So if you
see here 1 2 3 4 5 6 7 8 9 10 11 12 13
14 15. So nearly 15 uh
batches of inverters I have made with
four switches minimum of four switches.
So four switches means you can get a
full wave rectifier right so for sorry
full wave inverter. So from each and
every output I am taking a voltage
output here. Okay. So what I'm doing is
that I will be operating each and every
branches of circuit with a different
level of pulse with modulation
technique. Okay. See here here you can
see this one particular circuit is like
this. Okay. So one bridge rectifier is
there. So here you can see the output.
So for each and every switch I'll be
operating at different width of
operation on and off time. This is done
using the pulse with sorry pulse
generator what I'm giving. Okay. So when
I when I increase the duty cycle of on
and off period of the cir uh particular
switch what happens is I'm just
increasing the on time and off time. So
because of that the voltage level is
differing from each and every circuit.
When I club it together, when I add it
together and take it as a single output
from this point to this point, from
neutral to this point, right? If I take
the output, it will sum up like this.
What you are seeing here square. So what
happens is it is almost equal to the
sinosidal waveform. By doing that, what
you can do is that you can by using this
multi- level inverter, you can still
more increase the voltages also. If I if
I want more than 5 volt, what I will do?
I'll just add upon my another circuit so
that it will give more output. So like
that I can go on adding so that it will
increase more number of output uh more
number of higher output wtages also
right. So in pulse in generally you we
are using pulse with modulation
technique we are restricted towards this
peak. I can increase only this level.
Okay. Whereas here in this I can
increase my wtage also. So what happens
for higher level of application however
uh whatever output wtage I want that
much amount of branches I can go on
increasing. So that is the advantages of
this H sorry multi-level inverter. Here
you can see this is this is a EV motor
drive using a cascaded Hbridgeidge
inverter. See you can see here 1 2 3 4 5
15 Hbridge inverters are used to achieve
this 11 level output. Okay. So to
achieve this level output here you can
see 11 one one phase for 11 one phase
they have given one one output here to
the motor. Okay. So from here itself
they have taken the output and they are
giving it to charger also right. So why
they are giving to charger means so one
once this is being operated as any
generator or something at that time also
you can use it for power recovery. So
for that reason only they are using very
this type of uh thing. So but circuit
becomes very complex. Yes circuit
becomes very complex. I do I do accept
that but thing is that uh here the
nowadays what we are going to do now see
for example if I am operating a inverter
two level okay what I have to do for
each and every switch I have to put a
pulse uh pulse generating drive circuit
okay now what happened previously it was
like that now now everything has come to
that uh semiconductor's uh improvement
and its uh development now we are able
to make everything into a small IC or
chip right so we can program our own
pulse width and we can give it as a
through microcontroller we can feed it
to the inverter so what happens is see
in this example also I have just shown
here see I am having this many circuit
boards but the control the control drive
circuit I'm having is only single
control drive using this one single
control drive itself I will be able to
manage all the three units so adding
units maybe I can I I am occupying more
space but thing is that ultimately my
output becomes very smaller okay and
moreover if you check using pulse with
modulation technique if I am increasing
more switching frequency it may burden
the switch okay that it may burden one
single switch as I said it will produce
more heat and it will be it will lead to
thermal runaway situation also so if you
think in this aspect that will be
beneficial when compared to the circuit
complication and moreover Over for high
power application anyhow you are going
in for high power rated inverters and
motors. So if you are using high power
rated inverters ultimately that will
also increase in youth size as well as
weight instead you can go in for
multi-level inverters means you can
still you can get a more uh simp output
and better life lifetime actually it is
uh it can increase the lifetime of the
system entire system. See for example if
you are giving an warranty for your uh
vehicle for five years you can give it
for six to say 8 years 10 years also you
can give because this multi multi-level
inverter can withstand that much thing
and moreover you can add upon the power
ratings also easily by adding just the
chip you need just one board you can
increase the power rating also so these
are the advantages of using this
multi-level inverter okay so this is
where I'm ending this multi-level
inverter and we going into get into the
motors. So if you have any doubt
regarding these inverters, you may just
post in the chat box. I'll give a one
minute time. So by then I will address
your questions and then we will move
So can we proceed?
>> Yes. So we are just proceeding into the
motors now. Yeah. So in motors what we
are going to see is that we are
primarily going to see about the
classifications and different types of
motor and we'll see what is the basic
principle of the motor that is being
operated inside a electrical vehicle
system and we are going to see the
specialized motors like inverted fed
motors in which we are classifying that
in we are bringing into that brushless
concept brushless DC motor which is fed
into electrical vehicles and we are just
going to analyze about that BLC motor.
So this is what our workflow is going to
go for today as well as tomorrow's
session I guess. So as we go we'll we'll
go with the flow and we will just finish
it off and finally we will get into our
this is this is going to be our
pre-final module. So after this we will
enter into that uh microcontroller
programming. So tomorrow we'll see from
today afternoon till tomorrow we will be
seeing about motor and its drive system.
Okay. If time permits I will just give a
brief introduction to motor design tools
also. if you are interested right so yes
first thing these are few
classifications of motor see here here
you can see that based upon the input
which I'm giving to the motor it is
being classified into broadly two types
AC motors and DC motors so we have two
types of supply AC supply and DC supply
correct so based upon that I can
classify the entire motor system into
two types AC motor and DC motor right in
AC motors you can see induction motor
Synchronous motor, commutator motor,
wound rotor motor, squirrel gauge motor.
Similarly, if you see in the DC, you
have shunt motor, series motor, PMDC
motor, compound motor and separately
exited motor. Okay. Apart from these
things, we have a category called
special motors. Okay. These special
motors came into existence in the early
2000s. We can say like that or in '90s
also. We had few types of uh like for
example what I can say this universal
motor few concepts were available in the
'90s also actually. So what they made is
uh this the application of motor
actually increased. Okay. So when the
application of the motor got increased
according to my application I was in a
situation to reconfigure the available
motor. So based upon that what I thought
is because the role of motor came into
automization. So that actually made the
designers and the motor engineers to
design special type of motors to achieve
this. Say for example let us say very
precised control of motors is was
required. When the when the robustness
came into the application these types of
motors were most welcomed because I I
need to tilt the motor for only 10°. I
want to tell tilt the motor till
actually 90°. Within 30 seconds, my
motor has to run and stop. After 30
seconds, my motor has to rotate in an
anticlockwise directions. So, these sort
of inputs gave the designers more
challenges to achieve different types of
motor. Okay. So, this is actually a
interesting uh point in the motor
manufacturers also. So they were
insisted to make think and reconfigure
the available motor in that aspect.
Previously if you see based upon the AC
supply and DC supply you just choose a
motor and just put it. But here as the
application of motor increased it has
been a biggest challenge like how to
configure the available motor to the
application. So for that they made
changes in the rottor and stator and
that actually ended up in these types of
special motors. Okay. The first one is
stepper motor and then brushless motor.
We have servo motor, universal motor and
reluctance motor. So these are some
special motors. So if I just pick these
motors and categorize into the traction
category. Okay. So if I'm bringing it
into traction category,
these DC motors like series, shunt,
permanent magnet and separately exited
motors can be used for traction
application. when I if I see the AC type
of motor induction motor PMS permanent
manual synchronous machine and switch
reluctance motor can be used for
traction application. So in this
induction itself you have cage rotors
and squirrel gauge. So squirrel gauge
and wound rotor. So wound rotors are not
used for traction but cage rotors are
used in that permanent magnet
synchronous motor. You have interior
mounted and surface mounted motor. So if
you see you have PM permanent magnet
motor here, permanent magnet DC motor
that is BLC motor, brushless DC motor
and you have permanent manage
synchronous motor here. So predominantly
if you see you might have heard these
two motors in electrical vehicle
Yes. So you might have heard about that
uh P BLC and PMSM right now
uh I am just bringing into the concept
of motor first. First first we will
learn what is a motor. Okay actually to
be precise electrical motor is a device
that converts the electrical energy into
mechanical energy. Okay.
This is an source. This can be AC or DC.
That is your electrical input. You are
giving it into a motor that will change
your voltage and current which you are
giving at this point to torque and
speed. Okay. So this is what you a motor
is doing. How you can load a motor? You
can load a motor mechanically only
through friction or anything something
like that or the weight added upon that
motor. Okay. So these are the things the
load acting over a motor. Electrically
if you want to load the motor you can
just keep your input as constant and you
can continuously load this. So
electrically you're loading this motor.
So this motor can be electrically loaded
also and mechanically loaded also. If
you want to load output you have to uh
load mechanically. Whereas if you want
to load the motor in through towards the
input side then you have to load it
electrically. Okay. So principle wise
how I should understand how the motor is
rotating. Okay. So the basic principle
says that whenever a current carrying
conductor is placed in a magnetic field
a force acts on the conductor so that it
will show a mechanical motion. So this
is the a single line principle of how a
motor is working. Right? Now what you
can understand is that it a current it
is a current to create a magnetic field
as a fixed part of the machine that is
stator whose displacement sets a
rotating part that is whatever current
you are giving at this point it gives a
displacement at the rotar point. This is
an this is a definition with respect to
your vehicle. Okay. Whatever current you
are giving as an input to the motor that
will be shown as a displacement at the
wheel at the wheel of the vehicle. Okay.
So I give one voltage that will make my
motor to move a one 1 m 1 mm of
distance. So that is the principle of
motor with respect to electric vehicle.
Are you understanding this point? You
just give 1 volt it will make the motor
to move from one point to other. You
give 2 volt it will still more. you give
3 volt and you meet up to the rated volt
it will move show the rated displacement
of the vehicle. So this is how you
should understand the input and output
of the motor with respect to your
vehicle application that is electric
vehicle application. So I think this
point you have got clear. Now I'm going
into the basic principle of the motor.
Okay. So first what uh that one line
objective what we have studied one line
definition of definition or principle of
the motor what we have studied whenever
a current carrying conductor is placed
in a magnetic field it is going to
experience a mechanical force and that
mechanical force is the rotation okay so
I am going to practically check it or I
can going to practically understand the
situation that is what I'm going to try
it now see here I am creating a first I
need to create a magnetic field so what
is the magnetic field. Just take a
magnet, permanent magnet, keep it in the
north, keep it in the north pole. And
this is another magnet. Keep south pole
like this. So a magnetic lines of force
will flow from north to south by itself.
You need not do anything because this
will tend to attract. The physics is a
magnetic line of force will be flowing
from north to south by itself. You need
not do anything. And this is called as
the magnetic field.
Okay, you just take a magnet one should
be facing north pole and other other
should be facing south pole. So if you
bring these two magnet nearer from north
pole to south pole some magnetic lines
will flow by itself and that creates the
magnetic field. So I have created my
magnetic field. Now next
then I need a conductor. So what is a
conductor? It is a any type of material
a thin material and that material should
allow the current to pass through it. If
I if a material is allowing the current
to pass through it then it is called as
a conductor or else it is an insulator.
Okay. Now the conducting material what
I'm what I'm going to take is that now a
copper wire. So I'm taking a copper
wire. Okay. And then inside this what I
have to send I have to send current.
Okay. I have to send a current. So if
not only the current conductor I'm
sending a current through this. Okay. If
I send a current through this according
to the principle of motion what I should
get? I should get a mechanical force.
Okay. So whenever a current carrying
conductor is placed in a magnetic field,
it experiences a force. Okay. So that is
the principle of motor. Now you see here
now it is experiencing a force right.
This experiencing since the direction of
current is like this. That means what?
you are giving the positive terminal of
your voltage source from to this point.
If I give the positive terminal to this
point, my current direction will change
from here to here. Since my magnetic
field is like this and my current is
going through this, my conductor will
move upward. This is Fleming's left hand
rule. You might have studied it correct.
So Fleming's left hand rule you might
have studied in your 12 standard and
these things. So the magnetic field is
in one direction and your current is in
another direction. So your mechanical
motion will be going top. Okay. Like
this. Okay. Now actually my rotor has to
rotate in in what way? It has to rotate
in a circular way. So what I am doing is
I am taking the same conductor and I am
arranging in this aspect. The same
conductor I'm doing like this. I am
bringing like this and I am closing like
this. So what happens? I am sending the
current through this point. Correct? So
my current is traveling from A to B. A
to B means my current direction will be
like this. Right? And then from B to C
and C to D. Okay. C to D my current
direction will be like this. That means
what? Towards A to B then my force is
like the current direction is like this.
From C to D my current direction is like
this. So the cam same coil current
direction is changing. Correct? Since
this current direction is aligned with
the magnetic field, this will be
nullified from B to C or A to D. A to D
it will not go. But B to C. So if it is
going from B to C, it is aligned with
the magnetic lines of forces. So that
will actually get nullified. So one
direction is going in this way and other
direction is coming this way. Okay. So
what happens? One according to this law
here we saw no. So my current direction
is going this way means my conductor
will go upward. That means what? From A
to B this portion will go upward. At the
same time C and D this portion will come
down. Okay. So that makes a tilting
force. Okay. This is how this is made it
as a rotation. Okay. So it is making a
tilted form. Okay. So what I will do I
will make this the similar this type of
arrangement more more number of this
type of arrangement I will have. So that
continuously it will be rotating for
360°. So this will not this this may not
rotate till 360° because its weight is
very less. So what I will do is similar
type of conductors I will add more
numbers like 50 60. So what happens is
moment of inertia is increasing. So the
angle of inclination is also increasing.
So accordingly the rotation will take
more. Okay. So it will make a 360°
rotation. So I have to pass the current
right. So what I should do if I am
passing if I am connecting the wire
to A and D point this point this is
going to rotate. If this rotates
whichever I'm connecting the wire here
that will get twisted and it will cut
off. Correct? So for that what I'm doing
is I'm making arrangement like this
called brush.
Okay. So here you can see now this brush
square type here. Okay. That brushes
what it will do is it will just touch
the winding. It will not you will not
connect it like twisted. It will just
rub the winding. So through the brushes
I will just give this positive here and
this negative to here. Now what happens?
The current alone will go here. Even
this rotation is happening. This brush
will only rub. It is not connected. So
it can rotate smoothly. So is that
clear? Till now any doubt is there? You
may just ask
how a motor is rotating. Are you able to
So yes,
You are asking about competitor, right?
Will the current direction change? That
is based upon your uh supply which
you're giving. You know right if I go if
I'm going to give uh
this uh DC DC current right the current
direction will not change if I'm going
to give AC current the current direction
is going to change. So I'm coming to
this point commutator and this current
direction. Okay I hope so you are
understanding the points. So I'm just
for uh going forward moving forward in
with my content now. So I'm having a
commutator here. Okay. So what happens?
What this commutator is doing? Okay.
This commutator what it will do now? It
will make the current direction to
change alternatively. Okay. That means
what the rect you are using a uh
rectifier and inverter. No it is similar
to that. Okay. So you are giving a DC
supply only. But what happen? What
should what should actually happen is
that the current direction should
frequently changes in this line. Then
only your rotation will happen. The
current direction once it has to go in
this way in the same way the others
other time it has to come in this way.
Then only the rotation will happen. So I
am answering and uh breaking a myth
here. So you are having a commutator.
This commutator will actually change the
current direction and and it will give
you this is small mechanical
arrangement. Okay. So what you can
understand is that if this commutator is
not there okay instead of battery you
should give AC supply.
If this commutator is not there so this
commutator only what it will do it will
change this DC supply to AC supply and
it will give it to the winding. Okay.
This rotation should change this current
direction. No should be constantly
changing. Okay. So for that reason only
I'm having this commutator here. So what
you can see is that if commutator is
there you should say that motor is a DC
motor. If this commutator is not there
then the motor is a AC motor. To be very
uh in a layman language what I can say
is that in a DC motor if I break the
commutator then I it can be called as a
AC motor. So as as you all understood
this concept I understand I think you
have understood this concept correct or
not now I'm going to ask a question then
So I am getting yes. Okay. So now I'm
getting an answer. Yes. Yes. Yes. Yes.
Yes. Okay. So now I'm going to ask a
question. In this picture which you are
seeing right in that which part is the
rottor either this conductor part or
this magnet part north south. My answer
should be your answer should be like
north south or a b c d which is star and
which is rotar. Statar is the stationary
part. Rotar is the rotatory part in a
motor. So rot a motor has two parts.
Okay. One is star and another one is
rotar. Star part is stationary part.
Rotar part is going to be the rotator
part. Now I just wanted to ask one
question in my in your chat box. I want
the answer like this. state are NS or A
so I'm getting few answers ABCD wrote are
I want genuine answer you need not copy
from others you just tell whatever you
feel because this is not I'm not going
to evaluate your answer I'm just going
to clarify your answer that's it
so what you just think for a while and
answer Most of the replies till now I'm
getting is a b c d is rotor
So most of the answer is north ABCD is
rotor and ns is stator. Now I am telling
okay now I what I am telling is ns is
rotor abcd is stator.
What I am telling is ABCD is stator and
ns is rotor. Is that correct or not?
I am telling NS is the rotar and ABCD is
no. Okay. Now I am telling in this two
now I'll tell my answer. Okay. In this
two case NS as well as ABCD anything can
be a rottor or anything can be a sta.
Okay. The only option what you have to
see is that the mechanically if one part
is rotating that part has to be rot. So
if I make mechanically this part to be
stable these two will run around north
and south will run around. Instead if I
making this two part as the stand still
this will run around. So the rotation
can can either happen in the both the
direction. Okay both the cases. If I
hold this conductor to the in my hand,
north south will rotate around my hand.
If I hold north south in my hand, this
conductor part will run in my hand. So,
have you understood the concept and
principle of motor? Now,
it is not upon you are giving supply or
you are giving this thing. No, it is not
like that. The simple concept is you
what whatever you are making it to be a
construction wise stand still, the other
will rotate.
Have you understood the uh have have I
breaked the myth now?
Yes. So now I am breaking another myth.
Okay. So now I am concluding another
point. You are you are just going with
me or not? You should just answer. I am
telling in this world all the motors are
running with AC supply only. Am I
correct or not?
Second question.
After understanding this principle you
just tell me whether yes or no. I am
telling in this world all the type of
I'm getting more answers as yes and one
or two answers no. Okay. I'm still
expecting answers no or yes.
No, no. Now the no is increasing.
no
again it's time to break another myth
that is what statement I told was true.
Okay, in this world all the magnet, all
the motors are running with AC supply
only. Why? Because if you understood the
concept clearly, you should have
answered it correctly. See here, I told
no in this winding. Okay, this is the
winding. Now, as of now, for the
explanatory purpose, I'm taking this as
STAR itself and this as rottor itself
because logically you see here, I'm
connecting the supply here only. Okay?
So I am taking this as a stator. Now
okay and this is this is let this be
rotar. If I am treating this as stator
what I will do I will winding over here
and I will give supply here. Okay. So
now as for the logical uh explanation
I'm just taking this as sta in this what
I told the current direction through
this conductor has to be alternatingly
changing. then only that will be helping
for your rotation because see here this
conductor is now here. Okay. Now the
current direction is coming like this.
Correct? Similarly when the conductor is
taking a twist and coming to this point
this current direction should change.
Then only it will it will travel from
this point to this point it so it will
not. So
current alternating current should be on
the winding part means over the stator
means I should give AC current or DC current.
If I want to change the current
direction over my coil, should I give AC
AC correct. So in this motor at the
stator point inside the motor stator
from the stator I'm telling leave out
the supply whatever you are giving leave
about the supply whatever you are giving
leave that topic from the stator to the
rottor if I am giving only AC supply
then only my motor will run or else this
rotation I'm telling no this is called
as rotating magnetic field RMF in short
it is called as RMF the rotating
rotating magnetic field should rotate.
If the rotating magnetic field is not
rotating that will not influence your
rotor to rotate. So your sta rotating
magnetic field should rotate that will
lock with the stator sorry rot and that
will make the rotor to rotate. So if you
if I want your rotating magnetic field
to rotate then I should have only
alternating current. If I want to have
only alternating current I can give only
AC supply. That means in this world on
the stator on the wounded part we are
only supplying AC supply. If you are not
giving AC supply that means your
rotating magnetic field will not rotate.
If your rotating magnetic field is not
rotating your rotor will also not lock
with the rotating magnetic field. If the
rotar is not locking with the rotating
magnetic field it will also not rotate.
So at the stator all the motors are
provided with AC supply. If you're
giving though you are giving a DC supply
see here though you are giving a DC
supply you are making a mechanical
arrangement called comm commutator to
change the current direction in this
conductor. So supply wise only you are
giving DC but operating principle wise
your motors are running with AC supply
only. Is this myth broke down today? Are
Okay.
So now so far you might have had so in
during the course of time you had
certain concepts of understanding these
things fax and these things. Now you
understood what is actually the motor
and how it is works based on the
principle how I am just making the motor
to run and what I have to make actually
to make the motor to rotate. So this is
what the concept we have learned now.
Now we are going into speed and torque
the output of the motor. Okay. Now, now
you know mechanic electrically you are
given the supply electrically you made
the motor to rotate. Now at that output
what you're going to achieve is that
speed and torque. These are the
two output quantities of the motor. So
the two output quantities of the motor
what you can measure is that speed and
torque. So whatever the output you are
going to quantify by motor is only these
two concept that is speed and torque. Okay.
Okay.
So what is a torque? Okay, torque is the
rotational equivalence of the linear
force. Okay, so what you can understand
this is a clear example clearcut
definition. Torque is the rotational
equalence of linear force. What is a
linear force? When you move from one
point to other okay now you're walking.
Okay, what is your torque? Means the
first step what you are taking that is
your torque. Okay. So to take the first
step what you have to do is that you
have to overcome your weight first. You
have to overcome your gravitational pull
gravitational pull of the earth and then
the force may be opposing you to stop
you. You have to overcome that you have
to overcome all these forces and you
have to move forward the first step.
Okay that is the linear force. If that
is make made into a rotatory way that is
called a stark. That means what? The
first initial force of the motor to take
a first twist that is called a stark.
Actually that requires more input. Why?
Because the motor is having its own
weight. That is called as moment of
inertia. So whatever voltage and voltage
what you are giving to the motor right
that should overcome its rotar weight
first. Okay. And then gravitationally
that motor will have a pull towards the
ground. So that will also stop. Next
that rottor will have a friction over
the application whatever you are using
it. Either uh if you are taking
electrical vehicle that may be the road
surface the wheel the wheel is having or
a friction right that friction it has to
overcome it has to overcome the
gravitational pull and its moment of
inertia. After overcoming all these
things, the first requisite is taken
right that is called as torque. So if
you see in this equation also torque
will be equal to power by speed. That
means what? Torque is directly
proportional to its power. Okay. So
whatever power means what? In the few
last few classes we have studied what is
I'm asking in terms of electrical
quantity power is equal to what? V into
I wtage into current. So wtage into
current means your input parameters
voltage and current. If you product it
you'll be getting the power and that
power is actually directly proportional
to torque. So when you increase the
power your torque will just increase it
and it will start the first step of
motion first twist. Right? At the same
time torque is indirectly proportional
to its speed. Okay? As the torque is
increasing your speed is decreasing. As
the speed is decreasing your torque is
increasing. Okay? So that is what
indirectly proportional means. So what
is the meaning of speed? What is the
meaning of speed? Okay,
speed is nothing but when your torque is
just taking the first initial twist,
right? That has to be in a constant way.
If the torque is constantly repeating
and it is repeating continuous torque,
that can be related as speed. So the
first step it is taking as a first step
it is taking as a initial twist. Okay,
that is continuous. Okay, if that is
continuous, that is going to end up as a
speed. So the torque is actually
changing its face as a speed. Okay, in
the same line only torque and speed will
travel. It will start as a torque and
over a course of time it is slowly
changing into speed speed and speed is
attained at the maximum. At the maximum
speed your torque is zero. At the
maximum torque your speed is zero. Are
you understanding the relations between
torque and speed now?
Yes. So since more S is coming I'm just
continuing here.
See this is actually a small
demonstration to show the torque and
speed relationship. Okay. So here you
can see
here you are having a lengthy conveyor.
Okay. Now you are having a motor here
and a motor here. Okay. And you are
having a in the second case you are
having a motor here and a motor here. So
now in the first case just take the
first case. Okay. Now I am going to
place a motor here and here. Okay. So
what type of motor I should have?
Whether I should have a high starting
torque motor or highspeed motor.
I starting Turk one answer next. Highr.
So the answers are floating around like
high torque, high torque, high torque.
Okay, why I should have high torque? The
answer is correct because high because
the distance is more. Okay, so I don't
have the distance is more and I don't
have any supporting thing here. Right?
The full force, the length of the force
I have to pull means accordingly I
should have a torque over this point.
Similarly, I need to pull from here to
here. The conveyor belt means that
torque has to be given by this motor.
Right? Similarly,
this so I have to choose the high torque
motor and your answer is correct. Now,
since I need to increase the speed,
okay, I am not going to change the
I have used what I what I have used is I
have used a low starting torque motor.
Say for example at that time what I can
do I will just add some rollers in
between these points. So when I add
rollers to these points, I'm just
reducing the friction of the belt. So
with low starting torque also I can
achieve to pull this conveyor belt just
by adding a roller motors. So this will
actually what I will do it will it will
supplement my torque though minimize
minimize torque to achieve the speed. So
I can add more roller ball rollers
in between these conveyor belts. So that
if at all I'm going to have a less
torque machine also then also it will
match to run the speed. Okay, it is
correct or not. So this is this will
increase the speed of the conveyor belt.
So this is how what you can do is that
you can understood understand the
concept of torque and speed. So at terms
I need to have a high starting torque at
terms I need to have some highspeed
machine. So based upon your application
now you understood what is a power how
and how a power and torque is related
and how a torque and speed is related
how these three parameters are related
with each other. So according to your
application you can just decide like
what sort of motors you have to choose
whether it is it should be a high
starting torque or high speeded motors
and these things. All right. So this is
how the speed and working principle of
motor is there. Now next we are going
into the advanced level of motors that
is we are using in our electrical
vehicle. Now we are going into like
inverted fed motors. Right
now I'm just giving 2 minutes till now.
If you have any doubt you can just ask
or else we will just move on towards
So yes, I think you don't have any
doubt. So I'm just proceeding with the
inverted fed motors. Okay. Now what
happened? Now you saw about motors and
in the previous sessions you saw about
power electronics. Right? Now what
actually pre conventionally how the
motor will run is that probably you will
be given a supply between the supply and
the stat of the motor. There will be a
switch. Just switch on the motor. The
motor will run. If you want to switch
off the motor you just switch off the
motor. Instead if you're if you want to
have a speed control or something like
that. Now what happened is in between
that switch and the motor what they
added is say for example take an example
of your fan. Okay switch is there a fan
is there just you switch on it the fan
will run at the maximum speed and if you
switch off it the ma fan will switch
off. Okay then later on what happened is
in between the switch and fan they just
introduced a voltage regulator that is
regulator. So this regulator what it
will do your house is getting some 220
volt to 230 volt means it divided that
wtage into five groups according to the
rating of your motor. So according to
the rating of the motor it divided
itself into five groups and for each
setting it will give minimum wtage. When
the minimum wtage is given the motor is going to run at the minimum speed and
going to run at the minimum speed and when it is reaching at the maximum point
when it is reaching at the maximum point it will reach at the maximum speed of
it will reach at the maximum speed of your motor. So this is called as voltage
your motor. So this is called as voltage regulation. So they use regulator to
regulation. So they use regulator to just control the speed of the motor. Now
just control the speed of the motor. Now in this advanced scenario I I told about
in this advanced scenario I I told about that special type of motors right. So
that special type of motors right. So why the special type of motors role came
why the special type of motors role came means these type of things these type of
means these type of things these type of applications is everything physically
applications is everything physically controlled and it is externally it is
controlled and it is externally it is available. All the control parameters
available. All the control parameters are externally available. For example
are externally available. For example take a switch that is externally
take a switch that is externally available. Whenever you want you just go
available. Whenever you want you just go switch on your switch and just switch
switch on your switch and just switch off your switch by your hands. So it is
off your switch by your hands. So it is physically externally available.
physically externally available. Similarly if you take a regulator that
Similarly if you take a regulator that also will be placed in between these two
also will be placed in between these two physically this can also be controlled
physically this can also be controlled through hands. Okay. But if you see the
through hands. Okay. But if you see the robustic control see I don't know the
robustic control see I don't know the autonomous uh things came. So in every
autonomous uh things came. So in every application everything is now closed to
application everything is now closed to just you see just you speak just you
just you see just you speak just you touch your speed has to change. You have
touch your speed has to change. You have to see some from somewhere you have to
to see some from somewhere you have to control a motors here or that motor and
control a motors here or that motor and your controller is consled with your
your controller is consled with your application. For example, you cannot see
application. For example, you cannot see that itself. It will be inside this
that itself. It will be inside this concealed concealed body and it will be
concealed concealed body and it will be inside any application that cannot be
inside any application that cannot be physically bent there and controlled. So
physically bent there and controlled. So for that what we opted is at the same
for that what we opted is at the same time power electronics also boomed. So
time power electronics also boomed. So the power electronic circuit served as
the power electronic circuit served as in between the supply and the motor.
in between the supply and the motor. Okay. So we kept supply instead of
Okay. So we kept supply instead of regulator we kept power electronic
regulator we kept power electronic circuit and then the motor. Now
circuit and then the motor. Now everything is controlled through power
everything is controlled through power electronic switches. So whatever I want
electronic switches. So whatever I want to control through the switch uh to the
to control through the switch uh to the motor. For example, if I want to control
motor. For example, if I want to control the speed, I need to I I will not
the speed, I need to I I will not directly go and place my hands on the
directly go and place my hands on the motor or switch. Instead, what I will
motor or switch. Instead, what I will do? I will give supply to the I will
do? I will give supply to the I will give codings to the inverter module like
give codings to the inverter module like this this module right this module I'll
this this module right this module I'll just give the program to this module
just give the program to this module accordingly that the module will give
accordingly that the module will give the current pattern and voltage pattern
the current pattern and voltage pattern through this wire to this coil. So what
through this wire to this coil. So what happens is the my motor will run
happens is the my motor will run accordingly. If I want to reduce the
accordingly. If I want to reduce the speed I will reduce the speed of this
speed I will reduce the speed of this only I will reduce the speed of this. If
only I will reduce the speed of this. If I want to change the direction I'll
I want to change the direction I'll change the current direction of this
change the current direction of this which automatically influence this
which automatically influence this motor. So whatever I want to perform in
motor. So whatever I want to perform in the motor inside the motor I will not
the motor inside the motor I will not keep my hands inside the motor and I
keep my hands inside the motor and I will do it instead I have a
will do it instead I have a pre-programmed program accordingly my
pre-programmed program accordingly my control drive will run the motor this is
control drive will run the motor this is called as actually DC electronically
called as actually DC electronically computation this is called as
computation this is called as electronically computation because
electronically computation because electrically previously in the basic
electrically previously in the basic principle you saw know we had two
principle you saw know we had two magnets we sent everything electrical
magnets we sent everything electrical parameters only current voltage through
parameters only current voltage through regular through our supply only. So that
regular through our supply only. So that is electrically commutated. Here we are
is electrically commutated. Here we are and mechanically competed. They they
and mechanically competed. They they both are electrical as well as
both are electrical as well as mechanical commutated. Whereas here this
mechanical commutated. Whereas here this is electronically commutated because
is electronically commutated because electronically you are giving this
electronically you are giving this supply.
supply. Okay. So you are using the supply. These
Okay. So you are using the supply. These are electronically commutated. Through
are electronically commutated. Through electronical computation only you are
electronical computation only you are adjusting the performance of the motor.
adjusting the performance of the motor. So they are controlled through this
So they are controlled through this commutation techniques only. So this is
commutation techniques only. So this is very very important and this is how we
very very important and this is how we are these are these are the motors being
are these are these are the motors being used inside the electrical vehicle
used inside the electrical vehicle system also. So the role of power
system also. So the role of power electronics just boom because of that
electronics just boom because of that boom we we just implemented here and we
boom we we just implemented here and we know how the switches in the power
know how the switches in the power electronic circuits will work right the
electronic circuits will work right the switches and the parameters whatever you
switches and the parameters whatever you see inside how they will work. So we
see inside how they will work. So we probably use this to run this motor. So
probably use this to run this motor. So this is what we are going to do. Now
this is what we are going to do. Now coming to the traction motor mobility
coming to the traction motor mobility mobility companies what they are using.
mobility companies what they are using. See here I have listed out few data
See here I have listed out few data sets. See here these are few EV models
sets. See here these are few EV models electric hero electric A to B. We can
electric hero electric A to B. We can see just the power rating here. So the
see just the power rating here. So the power rating is nearly 0.5. So you the
power rating is nearly 0.5. So you the maximum power rating is 8.5 kilowatt.
maximum power rating is 8.5 kilowatt. Okay. OLA S1 which is this this was
Okay. OLA S1 which is this this was taken few years back. Maybe this has
taken few years back. Maybe this has increased now. So 8.5. So the minimum is
increased now. So 8.5. So the minimum is 0.5.25
0.5.25 we have. Okay. This is a old type of
we have. Okay. This is a old type of vehicle. So if you see the operating
vehicle. So if you see the operating vehicle ranges are very more and the
vehicle ranges are very more and the operating wtage is also widely under 48
operating wtage is also widely under 48 volt to 72 volt. And if you see the type
volt to 72 volt. And if you see the type of motor which is being used right. So
of motor which is being used right. So they are mostly BLC motor here. Okay.
they are mostly BLC motor here. Okay. Apart from this you are also using PMSM.
Apart from this you are also using PMSM. So now I guess uh you don't have a doubt
So now I guess uh you don't have a doubt between PMSM and BLC. Okay. BLC means
between PMSM and BLC. Okay. BLC means brushless DC motor. Okay. Brushless DC
brushless DC motor. Okay. Brushless DC motor. PMS means permanent magnet
motor. PMS means permanent magnet synchronous motor. PMS they are calling
synchronous motor. PMS they are calling it as AC motor and brushless DC motor is
it as AC motor and brushless DC motor is called as DC motor. If there is no
called as DC motor. If there is no brush. Okay. If there is no brush that
brush. Okay. If there is no brush that means what?
means what? in this diagram from this diagram I
in this diagram from this diagram I think you can understand
if I'm not what is the role of this brush here if this brush is not there
brush here if this brush is not there what will happen to the circuit see what
what will happen to the circuit see what will happen to the system
if I remove this brush what What will happen to this coil? I
what What will happen to this coil? I said this. So you just give me as an
said this. So you just give me as an answer in the comment box. If the brush
answer in the comment box. If the brush is not there, what will happen to my
is not there, what will happen to my winding?
No, you are answering it will take AC. No, that is commutator. That is
No, that is commutator. That is commutator. You are changing. I'm I'm
commutator. You are changing. I'm I'm asking about the brush.
If I don't have brush, what happens to the wire?
the wire? I said no. What is the role of the
I said no. What is the role of the brush?
Yes, it is twisted. The wire will twisted and it will get cut. So that
twisted and it will get cut. So that means what? Here I'm not going to use
means what? Here I'm not going to use wire. Instead of that what I'm going to
wire. Instead of that what I'm going to use is I'm going to use permanent
use is I'm going to use permanent magnet. So this is actually
magnet. So this is actually electromagnetic concept. Instead of that
electromagnetic concept. Instead of that what this coil is creating this is also
what this coil is creating this is also creating north south only. If the
creating north south only. If the current is going in this direction say
current is going in this direction say it will take create as north. In the
it will take create as north. In the same winding if the current is coming in
same winding if the current is coming in this direction this will create as a
this direction this will create as a south pole. Okay. So this is also
south pole. Okay. So this is also creating a north south only temporary
creating a north south only temporary magnet only. Instead of that I'm going
magnet only. Instead of that I'm going to replace it with permanent magnet.
to replace it with permanent magnet. Right. So
brushless DC motor. Coming to brushless DC motor, it is available since 1962
DC motor, it is available since 1962 but it has gained now the pro popularity
but it has gained now the pro popularity because of that EV application. Wherever
because of that EV application. Wherever the precision control is required with
the precision control is required with low noise it doesn't have low noise and
low noise it doesn't have low noise and uh they don't have windings. So what
uh they don't have windings. So what happens is the losses are very less. So
happens is the losses are very less. So combining these advantages this has
combining these advantages this has predominantly grown towards uh the
predominantly grown towards uh the extreme level of application. But if you
extreme level of application. But if you see here it is attracting the EV
see here it is attracting the EV application much more than the other
application much more than the other applications. So previously in toy cars
applications. So previously in toy cars small fan so you saw this DC motor but
small fan so you saw this DC motor but here in EV application it uh since EV is
here in EV application it uh since EV is booming you can see in this EV that
booming you can see in this EV that brushless DC motor role is very very
brushless DC motor role is very very predominant right so they don't have
predominant right so they don't have brushes so they don't so the losses is
brushes so they don't so the losses is very less instead of that we are going
very less instead of that we are going to use what we are going to use
to use what we are going to use permanent right so you can go on
permanent right so you can go on increase the number of faces also this
increase the number of faces also this is also an advantage Ages of BLC motor.
is also an advantage Ages of BLC motor. See the structure is like this only. So
See the structure is like this only. So you have a STAR right? Over the STAR you
you have a STAR right? Over the STAR you will be having coils. Okay. Here only
will be having coils. Okay. Here only you are going to give supply. This is
you are going to give supply. This is called as STAR windings and you have a
called as STAR windings and you have a rotor concept. Okay. You have a shaft.
rotor concept. Okay. You have a shaft. Okay. So over this rotar this rotar will
Okay. So over this rotar this rotar will have permanent magnet instead of your
have permanent magnet instead of your conventional motors will have here also
conventional motors will have here also winding only. Here also it will have
winding only. Here also it will have winding. it will create north and south
winding. it will create north and south pole right but instead of creating north
pole right but instead of creating north and south pole
and south pole temporarily I am just replacing that
temporarily I am just replacing that with the permanent magnets okay so I am
with the permanent magnets okay so I am also having this additional sensor
also having this additional sensor called hall effect sensor so what is the
called hall effect sensor so what is the role of this hall effect sensor so these
role of this hall effect sensor so these are the components structure of the BLC
are the components structure of the BLC motor we will see what is happening in
motor we will see what is happening in uh we will just move on with what are
uh we will just move on with what are the things inside the BLC motor and how
the things inside the BLC motor and how it is working how it is running these
it is working how it is running these things right now first the status okay
things right now first the status okay to be very frank again I'm telling to be
to be very frank again I'm telling to be very frank the stat of all the motors
very frank the stat of all the motors are same only the only change with the
are same only the only change with the motors are rotar only based upon the
motors are rotar only based upon the rotar configuration only you will
rotar configuration only you will categorize the motor generally the sta
categorize the motor generally the sta of all the motors are same okay so the
of all the motors are same okay so the stator has actually a more number of
stator has actually a more number of stampings like this. This is a brushless
stampings like this. This is a brushless DC motor. You can see these are the
DC motor. You can see these are the staar teeth. So the the staar teeth are
staar teeth. So the the staar teeth are arranged like this. Okay. And the
arranged like this. Okay. And the windings are made around this staar
windings are made around this staar teeth only. The gap between sta two
teeth only. The gap between sta two staar teeth is called as slot. Okay. I
staar teeth is called as slot. Okay. I will tell it you can see much more
will tell it you can see much more better. So these staar teeths are made
better. So these staar teeths are made of thin lamination seats and they are
of thin lamination seats and they are stamped around. For example, if your
stamped around. For example, if your motor is 30 mm, okay, if your motor is
motor is 30 mm, okay, if your motor is 30 mm, it will be like 3011 mm sheets.
30 mm, it will be like 3011 mm sheets. Okay, it will not be a 30 mm core. How
Okay, it will not be a 30 mm core. How you can understand is that take a
you can understand is that take a notebook. Your notebook how it is made.
notebook. Your notebook how it is made. It is not made as a single chart.
It is not made as a single chart. Instead, it is having some 100 pages and
Instead, it is having some 100 pages and 80 pages. Right? So, like that only
80 pages. Right? So, like that only status also will be there. It will be
status also will be there. It will be like thin sheets. Okay? Thin sheets are
like thin sheets. Okay? Thin sheets are arranged one one above the other and
arranged one one above the other and they are stamped and they are made at as
they are stamped and they are made at as a one structure. Okay. Just like your
a one structure. Okay. Just like your papers are arranged and you are making
papers are arranged and you are making making it as a note or record book. Your
making it as a note or record book. Your status stampings also has made like that
status stampings also has made like that only they are made as a stampings 1 mm 1
only they are made as a stampings 1 mm 1 mm 1 mm stampings and they make it as a
mm 1 mm stampings and they make it as a 10 mm whole structure. This if this is
10 mm whole structure. This if this is 10 m 30 mm it is divided as 1 mm 1 mm
10 m 30 mm it is divided as 1 mm 1 mm sheets. Okay, you can understand like
sheets. Okay, you can understand like this to yeah to reduce that 80 current
this to yeah to reduce that 80 current losses or these things that that is
losses or these things that that is logic we will also and moreover dying
logic we will also and moreover dying and core making a core of single core uh
and core making a core of single core uh thing will also be very very costly. So
thing will also be very very costly. So many things are there. Structurally you
many things are there. Structurally you cannot uh make uh 30 mm length as a
cannot uh make uh 30 mm length as a single core for uh drilling or something
single core for uh drilling or something also that is make that that will make uh
also that is make that that will make uh the system to be complex and engineering
the system to be complex and engineering is very tough in that aspect. So what we
is very tough in that aspect. So what we will do is we will do as thin thin
will do is we will do as thin thin sheets and arrange it that is more easy
sheets and arrange it that is more easy to cut that uh model also physically. So
to cut that uh model also physically. So that makes the choice of taking thin
that makes the choice of taking thin sheets than to make a single code. So
sheets than to make a single code. So there are many advantages of
there are many advantages of taking it in that way. So this is about
taking it in that way. So this is about the state coming to rot. As I said the
the state coming to rot. As I said the rotors are permanent magnet instead of
rotors are permanent magnet instead of windings are cage bars. So here you can
windings are cage bars. So here you can see the rotor shaft as a rotor position
see the rotor shaft as a rotor position sensors and it is electronically
sensors and it is electronically commutated. I will tell this. So here if
commutated. I will tell this. So here if you see this is a rotar core. Okay. Over
you see this is a rotar core. Okay. Over this I am keeping a north south north
this I am keeping a north south north south like this I am arranging a magnet.
south like this I am arranging a magnet. If my arrange a magnet over the core
If my arrange a magnet over the core like this then it is called as circular
like this then it is called as circular coal with magnets on the periphery. This
coal with magnets on the periphery. This is one type of arrangement of permanent
is one type of arrangement of permanent magnet brushless DC motor PM BLC. Okay
magnet brushless DC motor PM BLC. Okay BLC motor this is one configuration of
BLC motor this is one configuration of such rotor. So what is the other
such rotor. So what is the other configuration means? I can still place
configuration means? I can still place this magnet inside like this embedded.
this magnet inside like this embedded. Okay, embeddedly I will just keep my
Okay, embeddedly I will just keep my magnets like this. If you touch over
magnets like this. If you touch over this, you cannot feel the
this, you cannot feel the uh permanent magnet. You will just feel
uh permanent magnet. You will just feel that core. You cannot feel the permanent
that core. You cannot feel the permanent magnet. Is that clear? So that is called
magnet. Is that clear? So that is called as circular core with magnets embedded
as circular core with magnets embedded inside it. This is another
inside it. This is another configuration.
configuration. And this is circular core with magnet
And this is circular core with magnet inserted. That means what? You will
inserted. That means what? You will insert the magnet in the spaces. Okay.
insert the magnet in the spaces. Okay. So what is the difference between this
So what is the difference between this and this means if I touch over the core
and this means if I touch over the core here I cannot sense the magnet. Whereas
here I cannot sense the magnet. Whereas here in this case if you touch around
here in this case if you touch around the core you will feel the magnet at
the core you will feel the magnet at this point. You can feel the magnet at
this point. You can feel the magnet at this point. Whereas you cannot feel the
this point. Whereas you cannot feel the magnet here. Okay. So these are the
magnet here. Okay. So these are the certain few com configurations in which
certain few com configurations in which the rotors are available for BLC motor.
the rotors are available for BLC motor. Right?
Right? Now coming to the embedded system of BLC
Now coming to the embedded system of BLC motor. Okay. So it it is as I said these
motor. Okay. So it it is as I said these are electronically commutated correct.
are electronically commutated correct. So they are electronically commutated.
So they are electronically commutated. So how they electronically getting
So how they electronically getting commutation that is what we are going to
commutation that is what we are going to see now. Okay. So first the rotation how
see now. Okay. So first the rotation how the rotation is happening is we are just
the rotation is happening is we are just energizing the stator in a sequence okay
energizing the stator in a sequence okay we are going to energize the stator in a
we are going to energize the stator in a sequence and that sequence will be
sequence and that sequence will be logged with a permanent magnet in the
logged with a permanent magnet in the rotar and that's based upon that
rotar and that's based upon that sequence that rotar will follow that
sequence that rotar will follow that sequence and the rotation is happening
sequence and the rotation is happening okay so this is what the working of
okay so this is what the working of permanent BLC motor is there okay
permanent BLC motor is there okay So that is actually done by means of
So that is actually done by means of rotar position sensor that is called as
rotar position sensor that is called as all effect sensor. The rotar position is
all effect sensor. The rotar position is given by the sensor and that is called
given by the sensor and that is called as all effect sensor. The sensor type is
as all effect sensor. The sensor type is called all effect sensor. But to the
called all effect sensor. But to the application what we what we will tell is
application what we what we will tell is that is called as rotar position sensor
that is called as rotar position sensor because it will sense the position of
because it will sense the position of the rotor and it will give the signal to
the rotor and it will give the signal to the microprocessor unit that will tell
the microprocessor unit that will tell which switch should.
which switch should. So this is the principle. as a principle
So this is the principle. as a principle I will just explain and still more I
I will just explain and still more I will explain in deep when I with the
will explain in deep when I with the with the help of some images and these
with the help of some images and these things I will explain it okay as of now
things I will explain it okay as of now you understand the technicality behind
you understand the technicality behind it okay so I'm not trying to confuse you
it okay so I'm not trying to confuse you but using technical term I'm just
but using technical term I'm just telling technically you understand the
telling technically you understand the concept and then I will conceptually
concept and then I will conceptually explain so that you will relate with the
explain so that you will relate with the technicality so this is my idea behind
technicality so this is my idea behind this right now as the magnetic poles are
this right now as the magnetic poles are passing towards that
passing towards that Hall effect sensor. How the hall effect
Hall effect sensor. How the hall effect sensor will work is whenever there is
sensor will work is whenever there is obstacle over that sensor, it will give
obstacle over that sensor, it will give the voltage. So that particular voltage
the voltage. So that particular voltage will be carried to the state winding
will be carried to the state winding through the switches provided. So this
through the switches provided. So this is how the sequence is predicted. Okay.
is how the sequence is predicted. Okay. Now I'm just telling through an see this
Now I'm just telling through an see this is the all effect. Okay. First you learn
is the all effect. Okay. First you learn about the all effect. See here you have
about the all effect. See here you have a permanent magnet. Right? So this is
a permanent magnet. Right? So this is your sensor. Say for example you have an
your sensor. Say for example you have an all effect sensor. Right? Now what
all effect sensor. Right? Now what happens is as soon as this south is
happens is as soon as this south is reaching here this will be having
reaching here this will be having positive positive positive and this this
positive positive positive and this this will be giving a hall wtage here. Okay
will be giving a hall wtage here. Okay when south is coming here and
when south is coming here and interacting behind it. Okay when this is
interacting behind it. Okay when this is becoming positive ultimately in that
becoming positive ultimately in that sensor the opposite terminal will become
sensor the opposite terminal will become negative. Right. So this will become
negative. Right. So this will become negative and the hall wtage will be
negative and the hall wtage will be achieved as positive and negative. Okay.
achieved as positive and negative. Okay. In the similar hall effect when hall
In the similar hall effect when hall effect means what? If a sensor is there
effect means what? If a sensor is there and if it is getting any obstacle okay
and if it is getting any obstacle okay at that time the sensor will give
at that time the sensor will give voltage okay that voltage also is
voltage okay that voltage also is depending upon the poles of the magnet
depending upon the poles of the magnet see here instead of this north if
see here instead of this north if instead of the south if I get a north
instead of the south if I get a north over here what happens is this will turn
over here what happens is this will turn to negative and this will turn to
to negative and this will turn to positive so your hall wtage will be
positive so your hall wtage will be positive here and negative here so
positive here and negative here so you'll be constantly getting a voltage
you'll be constantly getting a voltage over here this voltage only what we will
over here this voltage only what we will give we will use it for giving it to a
give we will use it for giving it to a pulse.
pulse. This this voltage only we will be using
This this voltage only we will be using it as a pulse. Okay. So this is what
it as a pulse. Okay. So this is what first level of understanding. Are you
first level of understanding. Are you getting this point clearly? So that we
getting this point clearly? So that we can proceed. I'll just give 1 minute
can proceed. I'll just give 1 minute time. You just recolct whatever one or
time. You just recolct whatever one or two minutes time. You just recolct
two minutes time. You just recolct whatever I told till this moment. If you
whatever I told till this moment. If you have any doubt you just shoot the
have any doubt you just shoot the question the or else we'll just provide
question the or else we'll just provide proceed.
proceed. Just two minutes you just take process
Just two minutes you just take process whatever I have told you.
That means all effect sensor will detect north and south. So see all effect
north and south. So see all effect sensor will not detect whether it is
sensor will not detect whether it is north or south. Okay. The hall effect
north or south. Okay. The hall effect sensor are tuned in such a way that it
sensor are tuned in such a way that it is may maybe you can take it simply like
is may maybe you can take it simply like that also. Okay. It will detect north
that also. Okay. It will detect north and south all effect. If something is
and south all effect. If something is blocking whether it is south or north,
blocking whether it is south or north, it will be detecting by means of the
it will be detecting by means of the voltage which is getting induced in it.
voltage which is getting induced in it. So if it is south pole, it will create
So if it is south pole, it will create an positive and if it is north, it will
an positive and if it is north, it will create a negative. So this can be
create a negative. So this can be changed also. No issues.
So any other doubt? Shall we proceed?
Okay. Yeah. So shall we proceed? Yeah, I think we can
shall we proceed? Yeah, I think we can proceed here.
proceed here. Positive and negative sequence. Yeah,
Positive and negative sequence. Yeah, positive and negative sequence. What?
positive and negative sequence. What? I'm not getting your point. positive and
I'm not getting your point. positive and negative sequence means
negative sequence means we are telling like uh when the motor is
we are telling like uh when the motor is sorry the north and south pole is
sorry the north and south pole is rotated it will create a positive and
rotated it will create a positive and negative sequence I'm understanding in a
negative sequence I'm understanding in a way so it is correct yeah it will be in
way so it is correct yeah it will be in that aspect yeah
so I think we I'm going to proceed now so taking the drive system of the motor.
so taking the drive system of the motor. Okay. So now
Okay. So now this is a very important point over
this is a very important point over here. Right. So this is the drive
here. Right. So this is the drive system. See here from your battery now
system. See here from your battery now I'm just telling with the respect of uh
I'm just telling with the respect of uh thing itself from your battery you are
thing itself from your battery you are just giving a supply here. Okay. So here
just giving a supply here. Okay. So here you are having this part. Okay. Here you
you are having this part. Okay. Here you can find six switches. Okay. 1 5 3 4 2
can find six switches. Okay. 1 5 3 4 2 6. Is that clear? So what is the circuit
6. Is that clear? So what is the circuit called?
Reply in your chat box. What is the circuit?
I'm getting an answer. Inverter. Is that an inverter?
So I am getting answers like inverter. Okay. Since I have written as an
Okay. Since I have written as an inverter, you should not tell this as an
inverter, you should not tell this as an inverter. I asked what is this circuit?
inverter. I asked what is this circuit? This circuit is actually a bridge
This circuit is actually a bridge circuit. It is not a inverter or a
circuit. It is not a inverter or a rectifier because this can be a inverter
rectifier because this can be a inverter also or this can be a rectifier also
also or this can be a rectifier also based upon your switching sequences of
based upon your switching sequences of this switches and the input and output
this switches and the input and output where you are taking. If you give an
where you are taking. If you give an input here and take the output as the
input here and take the output as the these three point and you maintain a
these three point and you maintain a proper switching sequences, this is
proper switching sequences, this is inverter. Instead, if I am giving a
inverter. Instead, if I am giving a three-phase supply here and I giving a
three-phase supply here and I giving a proper switching sequences and I get an
proper switching sequences and I get an output here, this is a rectifier. Okay.
output here, this is a rectifier. Okay. So, this circuit is a bridge circuit.
So, this circuit is a bridge circuit. How you are going to use this bridge
How you are going to use this bridge circuit is a that will actually decide
circuit is a that will actually decide whether it is an inverter or a
whether it is an inverter or a rectifier. Okay. So this particular
rectifier. Okay. So this particular circuit can be operated as inverter also
circuit can be operated as inverter also or rectifier also. When this will be
or rectifier also. When this will be operating as an inverter when you give
operating as an inverter when you give DC supply get the AC supply outside and
DC supply get the AC supply outside and give it to the motor then it becomes an
give it to the motor then it becomes an inverter. Instead if you make the motor
inverter. Instead if you make the motor to rotate mechanically and take the
to rotate mechanically and take the power from here when you that is when
power from here when you that is when I'm rotating this motor and making it as
I'm rotating this motor and making it as a generator through regeneration my
a generator through regeneration my power my input current and voltage will
power my input current and voltage will travel in this wire and it will reach at
travel in this wire and it will reach at this point at but this particular time
this point at but this particular time if I change this switching sequences I
if I change this switching sequences I will get the DC output here. So what you
will get the DC output here. So what you should say is this circuit is not an
should say is this circuit is not an inverter or rectifier it is a bridge
inverter or rectifier it is a bridge circuit. how we are going to use it
circuit. how we are going to use it based upon that only you can name it as
based upon that only you can name it as a inverter or a rectifier right now as
a inverter or a rectifier right now as of now this is a bridge circuit from
of now this is a bridge circuit from this bridge circuit I'm taking three
this bridge circuit I'm taking three output leads 1 2 3 from three legs okay
output leads 1 2 3 from three legs okay I have just taken it and I have
I have just taken it and I have connected to the three faces this is
connected to the three faces this is called as three faces okay if I want to
called as three faces okay if I want to add four faces what I have to do I have
add four faces what I have to do I have to if I I if I have to create another
to if I I if I have to create another winding
winding and I have to take it and I have to
and I have to take it and I have to connect it to the other leg. So if I'm
connect it to the other leg. So if I'm using four windings, how many switches
using four windings, how many switches will be used?
Tell an answer. If I'm using four faces here it is three phase. If I'm using
here it is three phase. If I'm using four faces, how many switches will be
four faces, how many switches will be there? Eight. Correct. So as as the face
there? Eight. Correct. So as as the face is increasing for one phase, two
is increasing for one phase, two switches will be used. So as the faces
switches will be used. So as the faces are getting increased that is I if I
are getting increased that is I if I increase the faces over my BLC motor
increase the faces over my BLC motor accordingly the legs will also increase
accordingly the legs will also increase and the switches also will increase.
and the switches also will increase. Very good. Good answer. Now what I'm
Very good. Good answer. Now what I'm going to do is that now I have just
going to do is that now I have just connected to the faces of my motor.
connected to the faces of my motor. Okay. Right. Now I am having a all
Okay. Right. Now I am having a all sensor over here. So this is this
sensor over here. So this is this actually senses the position of my
actually senses the position of my rotar. Right. So when my rotor is at
rotar. Right. So when my rotor is at this point, it will give whether north
this point, it will give whether north or south pole is coming by means of
or south pole is coming by means of positive and negative voltage. So that
positive and negative voltage. So that positive and negative voltage will go to
positive and negative voltage will go to the position speed encoder here. So that
the position speed encoder here. So that will tell which phase has to be exited
will tell which phase has to be exited here. Okay? Whether one or two or three
here. Okay? Whether one or two or three this which has to be exited that means
this which has to be exited that means where I have to give my current. So if
where I have to give my current. So if one and two is one and six is on. Let us
one and two is one and six is on. Let us take this example. One is on and six is
take this example. One is on and six is on based upon the input given by this
on based upon the input given by this all effect sensor. This all effect
all effect sensor. This all effect sensor is giving the position by giving
sensor is giving the position by giving positive and negative it is telling one
positive and negative it is telling one is positive six is negative like that if
is positive six is negative like that if it is giving coding then one and six and
it is giving coding then one and six and actually switch on. So when the one is
actually switch on. So when the one is switch on what happens the current is
switch on what happens the current is coming here coming here switches on
coming here coming here switches on through one it is coming here going
through one it is coming here going there because you know these are
there because you know these are relatable with positive signs and these
relatable with positive signs and these are relatable with negative signs that
are relatable with negative signs that means this will create north pole this
means this will create north pole this is also for example this can create
is also for example this can create south pole also for example if this is
south pole also for example if this is creating a north pole this will create
creating a north pole this will create the south pole okay now it is coming
the south pole okay now it is coming here the current is coming here the
here the current is coming here the current is coming here. Current is
current is coming here. Current is flowing from upward to downward. Okay.
flowing from upward to downward. Okay. So now the current direction is this. So
So now the current direction is this. So probably this may create a north pole
probably this may create a north pole and the same current is traveling
and the same current is traveling through this with an opposite direction.
through this with an opposite direction. So what happens? This will create a
So what happens? This will create a south pole and then it will come here
south pole and then it will come here and this will reach this switch and this
and this will reach this switch and this will go and end up here. So this created
will go and end up here. So this created north and this created south. Similarly
north and this created south. Similarly by switching different different values.
by switching different different values. Say for example, let us take now three
Say for example, let us take now three and sorry h three and four. Okay. Three
and sorry h three and four. Okay. Three and four means what? The current the
and four means what? The current the positive current will come here. This
positive current will come here. This will reach here three. So three is
will reach here three. So three is connected to two. Correct? So the two is
connected to two. Correct? So the two is coming here.
coming here. Now this is be becoming north pole say
Now this is be becoming north pole say for example and four right? So it has to
for example and four right? So it has to take this path. So coming here this will
take this path. So coming here this will create a south pole and south pole will
create a south pole and south pole will create here. Since it is downward it
create here. Since it is downward it will go like this and it will reach here
will go like this and it will reach here and it will come out. So this is how the
and it will come out. So this is how the north and south pole is created and
north and south pole is created and based upon your hall senses the inputs
based upon your hall senses the inputs are given and the switches is coming and
are given and the switches is coming and this is how the drive system of BLC
this is how the drive system of BLC motor is working. This is nothing but
motor is working. This is nothing but you are converting a DC signal to AC
you are converting a DC signal to AC signal and that AC signal is given to
signal and that AC signal is given to the winding but from where the sequence
the winding but from where the sequence has to start that is decided by this
has to start that is decided by this position sensor because who knows at
position sensor because who knows at what time I have to switch on which
what time I have to switch on which winding? If I created this as south and
winding? If I created this as south and this as north and my rotar poles is also
this as north and my rotar poles is also at the same poles. This will not work. I
at the same poles. This will not work. I have to create an opposite pole. I will
have to create an opposite pole. I will tell during the working so that that
tell during the working so that that thing is taken care of this rotor
thing is taken care of this rotor position. Okay. Now this is basically a
position. Okay. Now this is basically a inverter. This is creating north and
inverter. This is creating north and south pole only. But in which way that
south pole only. But in which way that is decided by this rotar position
is decided by this rotar position sensor. This will give the signal here.
sensor. This will give the signal here. Accordingly the equation that input is
Accordingly the equation that input is given here. In the morning sessions you
given here. In the morning sessions you did know inverter and rectifier. While
did know inverter and rectifier. While you are doing you are giving that pulse
you are doing you are giving that pulse with modulation to each switches that is
with modulation to each switches that is given by this encoders.
given by this encoders. Is that clear? Now did you understood
Is that clear? Now did you understood the dry system of your uh PLC motor?
Yes. Okay. Let us check with others. Let's wait.
So, so now this this supply has been given
so now this this supply has been given and this is rotating and everything is
and this is rotating and everything is fine. Yeah. Now I have drawn here
fine. Yeah. Now I have drawn here certain outputs. See this is your 180°
certain outputs. See this is your 180° mode output or 120° mode inverter
mode output or 120° mode inverter output. You can check here. This is what
output. You can check here. This is what the output you saw today. Right? So
the output you saw today. Right? So apart from that I'm having here another
apart from that I'm having here another black color line here. This is called as
black color line here. This is called as the back emf. Okay. And this is the face
the back emf. Okay. And this is the face current waveform. Okay. So this black
current waveform. Okay. So this black color is the back emf. Based upon this
color is the back emf. Based upon this only what I will do I am keeping my
only what I will do I am keeping my rotar portion sensor angle. What I will
rotar portion sensor angle. What I will do is I how I will actually calibrate it
do is I how I will actually calibrate it is I will just keep my sensors and I
is I will just keep my sensors and I will rotate it manually. So if I rotate
will rotate it manually. So if I rotate it manually the sensor output will give
it manually the sensor output will give no that should be actually matching with
no that should be actually matching with this back back of profile.
this back back of profile. Okay. So this is actually the back of
Okay. So this is actually the back of profile. Based upon this only I will
profile. Based upon this only I will calibrate my rotar position that is at
calibrate my rotar position that is at the sensor position. You are keeping
the sensor position. You are keeping that sensor no at rotar. So that
that sensor no at rotar. So that position is calibrated by means of this
position is calibrated by means of this back MF only. Okay, this is an uh
back MF only. Okay, this is an uh additional information I just wanted to
additional information I just wanted to give you. And this back MF is
give you. And this back MF is trapezoidal and it is not pure
trapezoidal and it is not pure sinosidal. Okay, so I was telling about
sinosidal. Okay, so I was telling about another motor right permanent manet
another motor right permanent manet synchronous machine that is also it is
synchronous machine that is also it is same as BLC motor only but instead of
same as BLC motor only but instead of this trapezoidal back MF you will be
this trapezoidal back MF you will be getting a pure sinosidal waveform in a
getting a pure sinosidal waveform in a case of PMS. So that is the only
case of PMS. So that is the only difference between BLC motor and PMSM.
difference between BLC motor and PMSM. So it is also another myth. Technically
So it is also another myth. Technically there is no difference between a PMS and
there is no difference between a PMS and a back BLC motor. Both are same type
a back BLC motor. Both are same type only because there also you're giving
only because there also you're giving you are converting DC to AC only. Here
you are converting DC to AC only. Here also that is only but what we claim is
also that is only but what we claim is that the back MF is
that the back MF is trapezoidal in a case of BLC motor
trapezoidal in a case of BLC motor whereas this will be a pure sinosidal in
whereas this will be a pure sinosidal in a case of PMS. So this is what I just
a case of PMS. So this is what I just wanted to confirm here and I want to
wanted to confirm here and I want to just clarify that information just to
just clarify that information just to move around about the working. This is
move around about the working. This is what I was telling the angle is fixed to
what I was telling the angle is fixed to 90° electrical. So now
90° electrical. So now this is how the motor is working. See
this is how the motor is working. See here. So this is here is the stator.
here. So this is here is the stator. Okay. Over the stator only I'm winding
Okay. Over the stator only I'm winding like this. In this winding just follow
like this. In this winding just follow the animation over here. If the current
the animation over here. If the current direction is this way, this will create
direction is this way, this will create north and south pole according to the
north and south pole according to the current direction. Okay. If the current
current direction. Okay. If the current direction in opposite this north and
direction in opposite this north and south pole will change. This current
south pole will change. This current direction is only provided by this
direction is only provided by this inverter. So in the one in this one
inverter. So in the one in this one winding if one is switched on take this
winding if one is switched on take this orange color in this orange color
orange color in this orange color winding if one is switched on the
winding if one is switched on the current direction will be in this way.
current direction will be in this way. Instead if four is switched on the
Instead if four is switched on the current direction will be in the
current direction will be in the opposite way. That means if I want to
opposite way. That means if I want to create this coil as north pole I will
create this coil as north pole I will switch on one. If I create if I want to
switch on one. If I create if I want to create south pole over this wounded coil
create south pole over this wounded coil then I will switch on four. Is that
then I will switch on four. Is that clear?
clear? Are you understanding this concept?
Are you understanding this concept? change of current value. By changing the
change of current value. By changing the current, how I am I am how I am able to
current, how I am I am how I am able to change my north and south.
Yes. So just by changing the current value I am able to change whether it is
value I am able to change whether it is north or south. How I will change the
north or south. How I will change the current direction? By ch switching on
current direction? By ch switching on either the upper upper arm or the lower
either the upper upper arm or the lower arm I can change the current direction.
arm I can change the current direction. So this is how I'll do. So basically how
So this is how I'll do. So basically how it is working is when south pole is here
it is working is when south pole is here I have to create a north pole here so
I have to create a north pole here so that the unlike poles will start to
that the unlike poles will start to attract. So that is the working
attract. So that is the working principle. See here.
So what see just take this uh image as an example. The rotar is there. This is
an example. The rotar is there. This is the stator magnetic flux. Okay. So the
the stator magnetic flux. Okay. So the state ofar magnetic flux is this. Okay.
state ofar magnetic flux is this. Okay. Now the rotar is what what I'm trying to
Now the rotar is what what I'm trying to do is that I will always create a unlike
do is that I will always create a unlike poles near this rotor. So if this is
poles near this rotor. So if this is south this will become north. So if I am
south this will become north. So if I am traveling to catch this north this will
traveling to catch this north this will again move it. It will always move but
again move it. It will always move but it will not catch. Okay. So this will if
it will not catch. Okay. So this will if this animal is moving then also it
this animal is moving then also it cannot able to catch this magnetic flux.
cannot able to catch this magnetic flux. This is this is this is how it will
This is this is this is how it will work. I'll just still I have an
work. I'll just still I have an animation for you. Myself created this
animation for you. Myself created this animation. You can understand much more
animation. You can understand much more better. See here. Take this as a rotor.
better. See here. Take this as a rotor. Take black as north and south as red.
Take black as north and south as red. Okay. North pole and south pole. So this
Okay. North pole and south pole. So this north has to come here means what I
north has to come here means what I should do? If north has to come here
should do? If north has to come here means I need to create a south pole over
means I need to create a south pole over here. That means what? This portion I
here. That means what? This portion I have to turn red so that this black will
have to turn red so that this black will try to attract here. Then I have to move
try to attract here. Then I have to move this red here. Then again this black
this red here. Then again this black will turn from here to here. So this
will turn from here to here. So this will make the rotation. See here
will make the rotation. See here this red is continuously moving and
this red is continuously moving and making the black to follow around us. So
making the black to follow around us. So this is how the rotation is happening in
this is how the rotation is happening in the BLC motor. Are you getting this
the BLC motor. Are you getting this point?
see here I am alternatingly changing my north south in the state R and making
north south in the state R and making the rotor to follow the unlike poles.
the rotor to follow the unlike poles. How I will actually alternatingly change
How I will actually alternatingly change it north south means by means of
it north south means by means of switching switching it on the upper leg
switching switching it on the upper leg or the lower leg. Okay. So by constantly
or the lower leg. Okay. So by constantly changing these things I am able to
changing these things I am able to achieve this. Okay. All because of this
achieve this. Okay. All because of this rotar pressure sensor. The first signal
rotar pressure sensor. The first signal when it is giving correctly based upon
when it is giving correctly based upon that the sequence of this is followed.
that the sequence of this is followed. So the input from the rot rotor uh
So the input from the rot rotor uh position sensor is very very important
position sensor is very very important in the working of BLC motor. So from
in the working of BLC motor. So from this working you might have understood
this working you might have understood like
like the role of power electronics in the BLC
the role of power electronics in the BLC motor is predominant without the help of
motor is predominant without the help of powerronic circuit the motor will not
powerronic circuit the motor will not run. You cannot make the motor to run by
run. You cannot make the motor to run by directly giving a supply because it is
directly giving a supply because it is electronically only commutated. It has
electronically only commutated. It has to sense like at what position the north
to sense like at what position the north and south of rotar is there. Based upon
and south of rotar is there. Based upon that only it can create the field on the
that only it can create the field on the stator. Apart from this if anything one
stator. Apart from this if anything one is collapsed you cannot manage it. So is
is collapsed you cannot manage it. So is that clear? So without the role of power
that clear? So without the role of power electronics you cannot achieve it. Now
electronics you cannot achieve it. Now we are going into check with the speed
we are going into check with the speed versus star characteristics. Now I am
versus star characteristics. Now I am asking just a question to you. If I want
asking just a question to you. If I want to increase the speed of the rotor, then
to increase the speed of the rotor, then what I have to do in a BLC motor
I am not asking design-wise. I am asking control-wise. If I want to increase or
control-wise. If I want to increase or decrease the speed of the rottor, what I
decrease the speed of the rottor, what I have to do in a BLC model?
I'm not getting any answers. Torque should be increased. See, see
Torque should be increased. See, see again you should not give generalized
again you should not give generalized answer. You know how the BLC motor is
answer. You know how the BLC motor is working, right? You are giving supply.
working, right? You are giving supply. You are just connecting an inverter in
You are just connecting an inverter in between that you are just taking the
between that you are just taking the position of the rotor. Based upon the
position of the rotor. Based upon the position of rot, you are switching it.
position of rot, you are switching it. Okay. So what as I said previously
Okay. So what as I said previously whatever you want to control
whatever you want to control on the whatever control you want to be
on the whatever control you want to be achieved on the motor directly you
achieved on the motor directly you cannot control the motor. So whatever
cannot control the motor. So whatever you want to do you want to do it through
you want to do you want to do it through the bridge circuit. Whatever you want to
the bridge circuit. Whatever you want to do you want to do through the drive
do you want to do through the drive circuit only. So if I want to increase
circuit only. So if I want to increase the speed what I have to do
voltage increase will give the increased AC voltage but that doesn't make any
AC voltage but that doesn't make any sense right if you're increasing the
sense right if you're increasing the voltage
voltage the voltage the output wtage of the say
the voltage the output wtage of the say let us take an example let let us take
let us take an example let let us take this uh treat this as an inverter itself
this uh treat this as an inverter itself now I am increasing the voltage over
now I am increasing the voltage over here means what happens this wtage will
here means what happens this wtage will increase other than that what will
increase other than that what will happen now I want to increase the speed
happen now I want to increase the speed right so what I have to do
right so what I have to do switching speed increase very good so I
switching speed increase very good so I need to increase the switching speed
need to increase the switching speed okay you are increasing the speed of the
okay you are increasing the speed of the see based upon the switch only the rotor
see based upon the switch only the rotor is rotating right? If I increase the
is rotating right? If I increase the switching speed, what will happen? If I
switching speed, what will happen? If I increase the switching speed, what will
increase the switching speed, what will happen?
happen? This speed will increase. Correct? If I
This speed will increase. Correct? If I increase the switching speed, this speed
increase the switching speed, this speed will increase. The change of rotator
will increase. The change of rotator rotator will increase, which ultimately
rotator will increase, which ultimately end up in increasing this rot speed. So,
end up in increasing this rot speed. So, I need to increase my stator sorry
I need to increase my stator sorry switching speed. This in increase the
switching speed. This in increase the switching speed of this. Okay. If I want
switching speed of this. Okay. If I want to
to make the
make the rotor to change in the opposite
rotor to change in the opposite direction, then what I have to
want to make the rotar to change the direction of rotation. Now it is
direction of rotation. Now it is rotating in clockwise. Correct? If I
rotating in clockwise. Correct? If I want to change it in anticlockwise. Now
want to change it in anticlockwise. Now what I have to do
by changing the supply what you will get positive and negative will change. So
changing the polarity if I change the polarity what will happen? Changing the
polarity what will happen? Changing the polarity means this polarity will
polarity means this polarity will change. Okay this will become negative
change. Okay this will become negative and this will become positive. So what
and this will become positive. So what happens? So this will become north and
happens? So this will become north and this will become south.
So what I have to do is I need to change the switching sequence in the opposite
the switching sequence in the opposite way.
way. Okay. Instead of 1 2 3 4 5 6 I can go
Okay. Instead of 1 2 3 4 5 6 I can go with 6 5 4 3 2 1.
Okay. So like this you have to by this also you can change it. So if I want to
also you can change it. So if I want to apply brake then also what I should do?
apply brake then also what I should do? So whatever I want to do with the motor.
So whatever I want to do with the motor. If I want to apply a brake, I need to
If I want to apply a brake, I need to change the direction of rotation or I
change the direction of rotation or I need to change the speed of the
need to change the speed of the rotation. Whatever I want to do, I have
rotation. Whatever I want to do, I have I will do here only. Okay. If I want to
I will do here only. Okay. If I want to apply brake, what I will do? I will just
apply brake, what I will do? I will just short circuit one of the leg and that
short circuit one of the leg and that that is complicated but I will tell tell
that is complicated but I will tell tell for you. So what I will do is I'll just
for you. So what I will do is I'll just short circuit two windings and I will
short circuit two windings and I will let the current to flow through the
let the current to flow through the third winding. If I do that that is
third winding. If I do that that is called as
what? That is called as regenerative braking. What regeneration I'm doing?
braking. What regeneration I'm doing? I'm making the motor to operate as a
I'm making the motor to operate as a generator and the losses will become
generator and the losses will become take in this winding. This sort of
take in this winding. This sort of braking is called as regenerative
braking is called as regenerative braking and drum braking. Many sort of
braking and drum braking. Many sort of braking is there. Electrically you can
braking is there. Electrically you can break
break anything.
anything. Okay. So if I want to break just I will
Okay. So if I want to break just I will just short circuit these two terminal
just short circuit these two terminal and I will make the other terminal the
and I will make the other terminal the high current to flow through the other
high current to flow through the other terminal. So everything is depending
terminal. So everything is depending upon switches. So you can do any sort of
upon switches. So you can do any sort of arrangement by means of this power
arrangement by means of this power electronic controller. So this power
electronic controller. So this power electronic controller is controlled
electronic controller is controlled through this
through this decoders. Right? These are the
decoders. Right? These are the microcontroller. This micro using this
microcontroller. This micro using this microcontroller you just program
microcontroller you just program accordingly in whatever mode the
accordingly in whatever mode the switches has to on. this will switch on
switches has to on. this will switch on and switch off accordingly. It will
and switch off accordingly. It will affect the rotation of this motor. So
affect the rotation of this motor. So this is the
this is the biggest advantage of having a power
biggest advantage of having a power electronic circuit in between motor and
electronic circuit in between motor and the supply. Right now just
the supply. Right now just for 5 minutes I'll just uh conclude the
for 5 minutes I'll just uh conclude the session. Five minutes I will just
session. Five minutes I will just discuss about the speed and torque
discuss about the speed and torque characteristics. So this is the speed
characteristics. So this is the speed torque characteristics of a BLC motor.
torque characteristics of a BLC motor. speed will be in the x-axis. As you
speed will be in the x-axis. As you know, the speed and torque are inversely
know, the speed and torque are inversely proportional. As the speed is
proportional. As the speed is increasing, the torque is reducing.
increasing, the torque is reducing. Right? So, this is this could be your
Right? So, this is this could be your rated speed. Okay? If this is your rated
rated speed. Okay? If this is your rated speed. If you fix the straight line
speed. If you fix the straight line towards the rated speed and check with
towards the rated speed and check with your t that would be your rated t this
your t that would be your rated t this region is called the operating region of
region is called the operating region of your vehicle that is continuous start
your vehicle that is continuous start zone or continuous power zone. your
zone or continuous power zone. your motor, your vehicle is efficiently
motor, your vehicle is efficiently running over this zone only.
running over this zone only. Okay? Whereas at this point, the torque
Okay? Whereas at this point, the torque is inter intermittent. It can rise or
is inter intermittent. It can rise or decrease. This is not good for your
decrease. This is not good for your vehicle. Similarly, this is not good for
vehicle. Similarly, this is not good for your vehicle. Here the speed is
your vehicle. Here the speed is intermittent.
intermittent. Right? Now, this is actually the
Right? Now, this is actually the constant torque zone and constant.
So this is actually the operating zone of your vehicle system. So if you see
of your vehicle system. So if you see here, this is the example of a M BLC
here, this is the example of a M BLC motor which has 2 HP that is roughly 1.5
motor which has 2 HP that is roughly 1.5 KOW. It is operating under 36 volt or 48
KOW. It is operating under 36 volt or 48 volt with a rated speed of 3,000 RPM.
volt with a rated speed of 3,000 RPM. Sorry, maximum speed of 3,000 RPM. So if
Sorry, maximum speed of 3,000 RPM. So if this is maximum speed of 3,000 RPM,
this is maximum speed of 3,000 RPM, right? And this could be your rated
right? And this could be your rated speed that is,500 could be your rated
speed that is,500 could be your rated speed. This is actually your good
speed. This is actually your good operating zone. So you'll be getting
operating zone. So you'll be getting different torque operating zones.
different torque operating zones. So you'll be you can operate your motor
So you'll be you can operate your motor at different torque operating ranges.
at different torque operating ranges. That means what? In this zone only you
That means what? In this zone only you can operate at different peak torque uh
can operate at different peak torque uh rate torque zones. That is if you you're
rate torque zones. That is if you you're riding a vehicle suddenly you are
riding a vehicle suddenly you are supposed to have a brake. Okay. So
supposed to have a brake. Okay. So you're applying a brake again you are
you're applying a brake again you are accelerating. That means at that
accelerating. That means at that particular time you need a varying
particular time you need a varying torque at high. So that will be
torque at high. So that will be happening in this zone only. So this is
happening in this zone only. So this is called as
called as rated operating zone. This is called as
rated operating zone. This is called as continuous operation area. Here you can
continuous operation area. Here you can achieve whatever torque you want and as
achieve whatever torque you want and as well as you can achieve the rated speed
well as you can achieve the rated speed uh sorry the speed versus ratio will be
uh sorry the speed versus ratio will be maintained in this region very crucially
maintained in this region very crucially and correctly. So, so this is actually
and correctly. So, so this is actually termed as operational zone of a
termed as operational zone of a electrical vehicle system. Right? Now,
if you see the merits and demerits of your brushless DC motor, the merits are
your brushless DC motor, the merits are it has no field winding. So, there is no
it has no field winding. So, there is no copper losses. Okay? It can have
copper losses. Okay? It can have possibly very high speed because your
possibly very high speed because your speed is depending upon the switching
speed is depending upon the switching speed of the power electronic circuit.
speed of the power electronic circuit. The power electronic circuit can go up
The power electronic circuit can go up to whatever speed it wants. So based
to whatever speed it wants. So based upon your power electronic switching on
upon your power electronic switching on and switching off speed, the speed of
and switching off speed, the speed of the rotor can be achieved. So the
the rotor can be achieved. So the possibly high speed can be achieved. It
possibly high speed can be achieved. It can be operated at any as situation
can be operated at any as situation provided your power ser circuit are
provided your power ser circuit are conser.
Okay. It is not a it is actually a self starting machine. You don't have any
starting machine. You don't have any supplement to start over it. In this
supplement to start over it. In this motor the regeneration is possible
motor the regeneration is possible either for braking or power generation
either for braking or power generation both both the because since it is
both both the because since it is electronically commutated how much
electronically commutated how much amount of regeneration you want you can
amount of regeneration you want you can just adjust it adjust it based upon the
just adjust it adjust it based upon the duty cycle of your switches. Okay your
duty cycle of your switches. Okay your motor size can be at less uh less size
motor size can be at less uh less size also. This is another merits of your BLC
also. This is another merits of your BLC motor. When you take about demerits
motor. When you take about demerits since you are using permanent magnet
since you are using permanent magnet permanent magnets are very costly. So
permanent magnets are very costly. So that ultimately this will end up in high
that ultimately this will end up in high cost. Okay. Actually you uh if you take
cost. Okay. Actually you uh if you take a conventional motor you can just give a
a conventional motor you can just give a supply and you can make it to run.
supply and you can make it to run. Whereas it requires inverter circuit
Whereas it requires inverter circuit that will also actually increase your
that will also actually increase your cost. Okay. Since it is driven by a
cost. Okay. Since it is driven by a drive circuit drive circuit also it will
drive circuit drive circuit also it will become a complex thing. And since you
become a complex thing. And since you are using a permanent magnet in your
are using a permanent magnet in your motor, coging torque will be more. So
motor, coging torque will be more. So what is the meaning of coging torque?
what is the meaning of coging torque? Coging torque is the magnetic attraction
Coging torque is the magnetic attraction between your stator and rot. Your rotor
between your stator and rot. Your rotor is actually a permanent magnet and your
is actually a permanent magnet and your stator is a temporary magnet. Say let us
stator is a temporary magnet. Say let us take an example. If you are just
take an example. If you are just switching off your motor. Okay. Now in
switching off your motor. Okay. Now in your stator, it is north. Suppose your
your stator, it is north. Suppose your south pole of your rottor is getting
south pole of your rottor is getting aligned with your state and it is off
aligned with your state and it is off now. So in the stator it is north and
now. So in the stator it is north and rotor it is south it will tend to
rotor it is south it will tend to attract it will and it will become
attract it will and it will become magnetically locking. So when you again
magnetically locking. So when you again switch on the motor right at that time
switch on the motor right at that time it will try to hold it that is called as
it will try to hold it that is called as cogging torque. Okay it will not try to
cogging torque. Okay it will not try to move instead it will try to hold it. So
move instead it will try to hold it. So this is called as cogging. Especially in
this is called as cogging. Especially in BLC motor if you check it at a low speed
BLC motor if you check it at a low speed for example 10 RPM or 15 RPM like that
for example 10 RPM or 15 RPM like that you can feel this coging torque through
you can feel this coging torque through jerkness. The motor will show some
jerkness. The motor will show some jerkness. It will also give some noise
jerkness. It will also give some noise tuck tuck like that it will hold and it
tuck tuck like that it will hold and it will release. So this is called as
will release. So this is called as coging torque. So since we are using
coging torque. So since we are using permanent magnet there is high chances
permanent magnet there is high chances of coging torque in it. We have to
of coging torque in it. We have to reduce it or else it will show
reduce it or else it will show disturbances in the low speed when it is
disturbances in the low speed when it is operating at low speed. Okay. So this is
operating at low speed. Okay. So this is what I think still we I have certain
what I think still we I have certain things to discuss. Maybe I am winding
things to discuss. Maybe I am winding till here. If you have any doubt, you
till here. If you have any doubt, you can shoot out as a general question. So
can shoot out as a general question. So I will I'm ready to answer now. Still we
I will I'm ready to answer now. Still we have some five minutes. In this five
have some five minutes. In this five minutes you can just shoot out few
minutes you can just shoot out few questions. If you have any doubt you can
questions. If you have any doubt you can shoot out. I can just answer it. Maybe
shoot out. I can just answer it. Maybe we will we will take this into next
we will we will take this into next class also tomorrow morning also. So you
class also tomorrow morning also. So you can have your doubts and you can discuss
can have your doubts and you can discuss with me. Uh so if you have any doubt and
with me. Uh so if you have any doubt and if it is not answerable maybe I can find
if it is not answerable maybe I can find it out today and I can answer you
it out today and I can answer you tomorrow. So try to ask your uh
tomorrow. So try to ask your uh questions. This is your last 5 minutes.
questions. This is your last 5 minutes. I'm here to answer your queries now.
What happens when same poles on rotar and state? Your question is not clear.
and state? Your question is not clear. So the number of poles in state and uh
So the number of poles in state and uh rotor what you are asking is pole is
rotor what you are asking is pole is something different. Okay. If you are
something different. Okay. If you are asking motor motors teeth and state
asking motor motors teeth and state rotar poles means uh I will understand
rotar poles means uh I will understand in this way state teeth is 30 means the
in this way state teeth is 30 means the permanent magnet numbers also if 30 what
permanent magnet numbers also if 30 what will happen the motor will not rotate
because mechanically if you align it with that definitely there will be a
with that definitely there will be a magnetic locking so it will not work. So
magnetic locking so it will not work. So you should always have a fractional
you should always have a fractional number of ratio. Okay. If if you divide
number of ratio. Okay. If if you divide sta teeth numbers and the number of
sta teeth numbers and the number of permanent magnets, if you divide it, you
permanent magnets, if you divide it, you should not get a even number. You should
should not get a even number. You should get a fractional number. Then only it
get a fractional number. Then only it will be helpful for rotation. Or else
will be helpful for rotation. Or else coging will be more. It will not allow
coging will be more. It will not allow the rotor to rotate.
So our plan will be so before concluding I'm just telling about the plan
I'm just telling about the plan workflow. So tomorrow we will be seeing
workflow. So tomorrow we will be seeing about the design aspects and parameters
about the design aspects and parameters of this BLC motor. How we should choose
of this BLC motor. How we should choose a motor for designing and how we have to
a motor for designing and how we have to pro move towards designing aspect of
pro move towards designing aspect of motor that we will see in the morning
motor that we will see in the morning session and in the afternoon session
session and in the afternoon session you'll be having a demo of uh motor with
you'll be having a demo of uh motor with the drive system how to simulate it and
the drive system how to simulate it and how to check it with that uh result
how to check it with that uh result these things we will be seeing in the
these things we will be seeing in the afternoon session and finally the Friday
afternoon session and finally the Friday session the final day that is the final
session the final day that is the final day of my session so in that session
day of my session so in that session you'll be having how embedded system is
you'll be having how embedded system is controlling all the systems we will
controlling all the systems we will using some Arino board something like
using some Arino board something like that and we will try to develop a
that and we will try to develop a prototype if I'm going to develop a EV
prototype if I'm going to develop a EV prototype how it would be in that aspect
prototype how it would be in that aspect we will see right
we will see right so I hope as per uh our commitment in
so I hope as per uh our commitment in the first day class we are trying to go
the first day class we are trying to go on a flow we will try to cover as much
on a flow we will try to cover as much as possible in the limited time so in
as possible in the limited time so in near future if you want to contact me
near future if you want to contact me also during the last day of session
also during the last day of session maybe I will share my contact or
maybe I will share my contact or something you may just uh contact me at
something you may just uh contact me at you may write a mail or you may just
you may write a mail or you may just type my name in the LinkedIn and you can
type my name in the LinkedIn and you can check so I can just uh
check so I can just uh so tomorrow I'll try to share my profile
so tomorrow I'll try to share my profile if possible so I hope so I can share it
if possible so I hope so I can share it so if I share it then it'll be helpful
so if I share it then it'll be helpful for you you can just stay connected with
for you you can just stay connected with me and you can ask your queries through
me and you can ask your queries through those points those mediums also yes I
those points those mediums also yes I think that is for uh today and uh I
think that is for uh today and uh I think we will wind the session for now.
think we will wind the session for now. Thank you for being with me. Let's meet
Thank you for being with me. Let's meet tomorrow. Thank you. You may leave now.
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