# Help required for 3ph induction motor

I am looking to design a driver circuit that can run 33v AC induction motor through 48V Battery for Electric Vehicle.The motor tag is attached. I have seen 33v AC induction for the first time.
I was able to design 3 phase half bridge driver on proteus but as proteus does not have induction motor I can not test it. Also, I dont have much experience in power electronics. Can anybody guide me how I can control the speed and direction of this motor using Arduino ?

Your circuit looks interesting however I cannot read it nor determine what parts you used. It appears you use N channel devices for both upper and lower FETs. This causes me to assume the driver chip has a charge pump to drive the gate of the upper FET or a higher voltage supply. I would suggest you spend some time understanding 3 phase circuits and how they work. This link will help you get started. How a Three-Phase Motor Works | Sciencing

You might need to learn more about motor control - induction motor control is nearly the hardest sort
to control alas!.

I found these lectures useful, but its quite a high level and assumes familiarity with control theory

The simplest scheme for induction motors is dumb V/f control - this might be a good starting point as
no feedback is needed.

Hi,
Welcome to the forum.
Your circuit/code outputs 3 squarewaves offset and not 3 sinewaves which the motor is designed for.

This will make a big difference to how your circuit will perform and survive?
An inductive load responds and has a load characteristic different in square-wave to sinewave powering.

Have you considered the current that the motor will need to run?

You should be able to model a 3ph motor in proteus, it will be a combination of resistors and inductors basically.
The cosO of 0.86 should help.
Tom...
PS, The resolution of the circuit diagram is not high enough to read component labels. Did you export the diagram as a jpg or did you screen grab?

TomGeorge:
Hi,
Welcome to the forum.
Your circuit/code outputs 3 squarewaves offset and not 3 sinewaves which the motor is designed for.

All electronic motor control uses square waves for the voltage - the current can be sinusoidal
even with PWM drive as it is smoothed significantly by the winding inductance.

3-phase PWM with sinusoidal variation in duty cycle is a common technique.

Hi

All electronic motor control uses square waves for the voltage - the current can be sinusoidal
even with PWM drive as it is smoothed significantly by the winding inductance.

Yes I am aware that PWM is modulated to produce a current/voltage that is sinusoidal due to the motor impedance, but does the OP know that.
Think a UNO would be pushing to do this job in modulated PWM form.

Tom...

Hi all! There's here a note about the implementation of a V/f control for an induction motor. You may want to use the attached simulation model to see how it works: https://kb.imperix.com/x/OAkz
Hope it helps!
Matt

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