Off-line identification of PWM driven induction motors using reference voltages

In this work we present a method for off-line identification of induction motors with PWM drives, i.e., the standstill estimation of all its electrical parameters. The method is achieved when we digitize the PWM driven induction motor model by considering the PWM signal from the inverter as a sequence of continuous impulses. The PWM inverter nonlinearity caused by the turn on/off time dependency of the current level in the switching transistors is modeled, allowing the method to be based only on reference voltages and measured currents. Simulation and experimental results illustrate the methodology.