When speed is controlled by varying the frequency in a VVFD (Variable Voltage Variable Frequency Drive), what is the need of varying the Voltage?

Thanking you in advance...

Sanjeev

 

In simple terms, the ratio of voltage to frequency (i.e. V/Hz) is related to the motor flux which is proportional to motor torque. Thus, if the V/Hz ratio is not constant then motor torque is affected.

 

Thank you, Chris.