A three phase motor drive using IGBTs and constant V/F speed control with slip regulation

This paper deals with the design and analysis of a three phase induction motor drive using IGBTs at the inverter power stage. An analysis of the steady state equivalent circuit model of an induction motor is presented to establish the equations that justify the use of a constant Volts/Hertz speed control. In order to compensate the voltage at low frequencies it is necessary to obtain the equivalent circuit model impedances by means of laboratory tests. The paper also describes the design of the control stage and presents the results obtained from the motor operating at different frequencies