Measurement of rotor time constant taking into account magnetizingflux in the induction motor

摘要

Rotor time constant is essential for high performance motorcontrol in the induction motor. A simple and exact measurement method ofrotor resistance and rotor time constant of induction motor is proposed.A DC current is injected to the magnetizing inductance, and then themagnetizing current is discharged to the rotor, so that the voltage istaken at the stator. Then the measured stator voltage has information ofrotor time constant as a function of magnetizing current. In this paper,rotor time constant obtained from conventional method and the proposedmethod are compared. The accuracy of the measurement is tested with avector controller by a linear relation between the input torque commandand output torque at steady state