Let's understand the speed characteristics of electric motor, it will represent electric motors in
terms of its speed characteristics.
In the previous version we have seen that electrical motor is a combination of electrical system, magnetic
system and mechanical system.
If we further expand this blog Bigham view of electric motor, then we can help this block diagram of
electric motor.
So that is the electrical system.
It represents the supply voltage and current will be, according to the electrical system parameter
that parameters that at a distance inductance and capacitance after winding up the electric circuit.
So inductor register and capacitor army, electrical barometer's and converters are also the part of
the electrical system.
But for the simplicity, if we consider, then current development is depend upon the electrical system
parameter and upon the supply voltage.
The magnetic circuit produced a thought depending upon the current and a number of dun.
Magnetic system parameters that dance off the circuit of magnetic material that I am still and at a
gas plant, so all this will decide the.
Produce our products, produce from the Koran, so magnetic circuit barometer's are the and mechanical
system parameters remain the same as we discussed in case of Waker.
This is mechanical system parameter after the only that means the inertia for Fruita it depend upon
the rotaru weight and shape as well as the frictional.
Component, but frictional component will be very less because of bearing arrangement.
We use the bedding to reduce the friction as much as possible with combat friction after a vehicle tire,
the friction of the bedding are very less.
Now, if we consider this system add up to this point, we need some relation.
How tight will produce?
Depending upon the voltage and current, we will have the steady state equation as well as dynamic equation
in electrical engineering to meet this requirement.
How much can we produce with supply voltage or for the constant amount of current?
Now this model parameter, if we consider only the initial rotor and the frictional losses frictional
component, if we applied this thought in mechanical system opposing talke, only the inertia component
is and frictional component we anticipate will be depending upon the component.
But when motor is loaded, that means something is attached in case of an electrical vehicle, if we
call it that, soft of the motor is attached.
We will consider the direct track.
So that means this motor, soft speed and wind speed cannot be difference if we want to include the
vehicle system perimetral also because it is also a mechanical parameter.
Let us consider the separately getting the vehicle model as we have discussed and if we call model represent
the supply torque will result in speed.
If you recall the opposing component in the vehicle parameter, the aerodynamic decoction, that aerodynamic
drag force then.
MP and frictional company.
So this opposing force that to mortar to represent the Bardella by the martyr.
So if we are driving the vehicle with the electrical motor, that means the same task that is developed
by the motor need to supply the vehicle.
And it will result in speed depending upon the opposite opposing car.
That is also due to the gradient constant.
If it is an incline, it will be different.
So this opposing car we need to inculcate here because we cannot supply the speed to the vehicle motor
and we need to modify this to what it means.
In this case, they are opposing Turca.
Opposing force or opposing torque are only the inertia of the motor and frictional component of Taruta,
but it is very less due to betting inertia.
Rotaries also very less with compared to the weight of the motor.
So if we want to merge the two system, Electrical and Wacol Electric Motor Vehicle, then we need to
only change it in addition to this two component of motor inertia and friction.
We need to get opposing Tarkoff, this vehicle system that is the quotient M and this.
The Indian component.
And U.S. data.
So this all now are opposing component, but Innocenti signal component would be very less, but we
can include it.
So when we supplied the voltage, according to the electrical characteristics, it will produce the
current according to the motor magnetic characteristic it will produce to talk and according to this
mechanical system, it will result in the final steady state speed.
So if we again recall the spirit or characteristic of the vehicle, we know that it is the speed that
is attained for applying the some constant amount of thought.
So we have already discussed how to direct this characteristic of vehicle mechanical parameter.
If we apply the certain constant Knewton meter of thought, the final status to speed it will attain.
And if we going recall the top speed characteristic of a vehicle.
So what is this now, this characteristic, it also called the lower characteristic to the motor because
vehicle is at the lower.
So all this vehicle opposing force, opposing torque are opposing to the motor speed also.
And this two speed will remain the same if we consider it is attached with this soft.
So this characteristic represent the certain minimum amount of torque required to achieve the steady
state speed so that we have seen some minimum park is required yet to achieve the desired speed.
Now, if we discuss the same thing with electrical parameter, we need to understand an electrical system,
the capability of produce maximum torque.
It also depend upon the speed because the electrical system opposing force due to this magnetic component
is the best in each and every motor.
And that became depend upon the speed.
That means the speed also reflect the amount of current that flowed through the electrical system.
And this feedback loop inside the motor will result in we are having the Surtain maximum amount of power
that can be produced is very with the speed.
So in case of motor, if we produced by the motor is applied to the mechanical system, it will result
in speed.
But the speed characteristic is something that represent the maximum amount of talk that can be produced
by the motor with this training, the current limit and voltage limit.
So we are having the restriction in the maximum current limit due to the winding diameter of the distance
and voltage limit also to the installation of winding.
So motor depending upon the motor rating that we can supply the maximum current and not beyond that.
And it will limit also the maximum, but with the limit, also the maximum torque ready with the speed.
So at certain speed, the maximum that can be developed by the motor will vary in electrical drive.
Subject of the electrical engineering, the students studying in detail how the car characteristics
change and how the steady state and dynamic equation can be represented in between current and time.
So if we understand and grow the speed characteristic of this motor, the all the motors represent almost
the same characteristic.
But the induction motor and seagrass model have slightly different characteristics.
But the concept remains same.
Is that dark characteristic of you can compare it with the D.C. model that includes D.C. and more to
be in D.C., etc., and that is all electronically commentator Motus also represent the same toxified
characteristic.
So what this talksport character you can see in Y-axis, we are having thought this is the maximum amount
of thought that can be produced by the water at a certain amount of speed.
That means the maximum amount of torque for some bass speed is remaining constant and why this mechanism
talk is limited due to current limits, because we cannot inject the current higher than this limit
that we cannot produce to talk higher than this limit.
So that a certain amount of speed, the current limit remained constant and this characteristic represent
the maximum current limit.
So if we consider we supplied the maximum voltage or maximum current limit, consider the constant current
and this will be the maximum thought that can be developed by the motor at a certain speed.
If you go beyond this base speed, we can see the target is reducing.
So see the target reducing.
But current is still same mechanism, currently same, and because Mortara has the maximum limited amount
of power we can limit, the current voltage constant current is constant and power is constant.
But even though at higher speed the target will be reduced, the maximum torque produced by the motor
will use at the higher speed.
So we can see this is the constant power that is in.
When your reduction in torque takase depend upon the inversely proportional to the motor speed, if
creating this dark will reduce and inversely proportional relation make it a constant power.
This is called the maximum power of the military, the first 10 kilowatt motor.
So if we multiply the TARKAN speed output of the mechanical output, power will remain constant during
this region.
So if models designed to operate at the maximum efficiency in this region, so we will get the highest
efficiency in this region and we are interested more in this constant power reason to expand this constant
partizan, because you can understand more yet operating at the maximum power point or the greater power
for which it is designed.
If further, if we required to further increase in speed, it's possible, but in this case, takase
inversely proportional to the square of the speed.
And due to this, the takase reduce with the much higher rate, with increasing speed.
So your power is also reducing that.
This is the constant power.
This is the constant thought.
And yet motor power is reducing what is meaning of power is reducing.
And currently still Castanza throughout this all point, the maximum current is still constant during
the 20.
So it is also doing 20 for this reason.
It is also doing 20 NPF during this operation and also doing 20.
For this reason.
But yet the output power is reduced.
So you can see the motor is doing the same amount of current output.
Mechanical power is getting reduced.
We are more interested in this vision.
Now, if you recall the fourth characteristic of the icy engine and compared with the top speed characteristic
of the motor, then we can have idea in its engine we required the gear arrangement and the force that
can be produced back and forth that can be produced at a certain speed is in go and it is reducing with
the speed.
If you recall then it was something like this is for first gear or second gear or target.
So.
That's the limitation.
And now if we draw that.
Lower characters are the top characteristic of the electric vehicle or vehicle load.
So if you recall, that white driver can draw something like this and if we call this the dark, that
will represent lower thought.
So what are the lower court is opposing or due to the mainly drink caution and empathy?
And this is the thought developed by the electric motor.
So at a certain amount of speed, we required the minimum amount of thought and a certain amount of
speed, the motor capability that can be developed, some amount of thought.
So if we consider these two characteristics and if we supplied the motor directly with the full current,
that means maximum current.
That is limited.
So what will happen at this speed?
Our law or vehicle demand 13 million out of torque, but the total deadlock by the motor is too much
higher than what is demanded at certain speed.
So whatever the result, the thought developed by the motor is too large.
Then motor speed will increase with very high rate of rise in speed and a speed increases.
That means both motors.
After that, the vehicles of speed will increase and this difference will reduce.
So if when the speed is reaching toward this intersection point, as long as speed is reaching this
point, you can see the difference is getting reducing here.
And if we consider this point a pause at this point of intersection, the dark by the motor and are
required by the law, the difference is less with compared to starting, and that means the rate of
radar speed will reduce.
But still speed is increasing.
Only the rate of increasing will reduce.
And when it's come to this point, we will have the steady state speed.
And for this.
Amount of currency.
When we applied the maximum current to the Märta, then we will achieve this maximum speed for this
vehicle that this is how we can.
Use the lower characteristic that Mr. characteristic of vehicle and characteristic of motor to understand
the performance of the vehicle in terms of maximum speed.
Now, if we further discuss about the.
How can we?
Jane.
The current limit and how the markets will behave in speed control, so we need to understand, if we
consider the reduction in current limit so much to spare control, then we will have the next characteristic
with the reduced current, something like this.
So in this case, if we apply the less current, then we will have this operating point and reduce speed.
Now, if we further reduced the current.
And we can have the intersection point and now you can have idea how the speed control can be possible
by controlling the current voltage of the motor.
The characteristic vary slightly, according to the different models in somewhat of to square up the
current somewhat comparable to the current, and there is also nonlinear relation between the start
up and supply voltage for 13 models.
So we need to understand how we can have the best control by controlling the parameters that govern
the speed characteristic of electric motor.
So you got an idea about what is.
Characteristic of electric motor, what is load characteristics of a vehicle and how we can combine
these two to.
Analyze the behavior of the vehicle when it is supplied by the electric motor.