Speed And Direction Control of Motor

[ENE]

Hello,
In case of DC we use H-Bridges To control Dc motor direction and Speed with PWM.
But in case of AC motor Single phase and 3 phase motor how to control Speed and direction?

 

[MalcolmB]

Hi...
I reckon your best bet would be a Variable Frequency Inverter drive.

 

[ENE]

How it will work i mean in H bridges there is mosfet with PWM channel.
in the we will change the frequency of 3 phase how?

 

[Harrison G]

You can shift the direction of an 3 phase motor by swaping two of its three phases. The speed depends on how hast the stator magnetic field rotates. So you can change the AC frequency if possible or change the supply voltage, but i recommend someone who works with electrical machines to reply to you.

 

[CWatters]

Perhaps see...
http://www.me.ua.edu/me360/spring05/Notes/Topic17-AC_Motor_Speed_and_Other_Motors_sv.pdf

It is possible to use PWM to produce a sine wave of variable frequency. See page 5.

 

[ENE]

Hello,
I know the theory procedure we use PWM with sin table in look up i think