A time domain equivalent circuit for the inverter-fed induction motor

Abstract

This paper derives an equivalent circuit for an induction motor. This model can be used in a time domain simulation to study the steady state performance of drives when the motor is supplied from a voltage type variable frequency inverter, and is particularly useful when used in conjunction with a time stepping circuit analysis program. It is shown that the conventional equivalent circuit model does not give the correct current waveform in cases when the applied motor voltage contains harmonics. This is allowed for in the new model and a comparison is made with a full representation of the machine using coupled stator and rotor windings.