A direct measuring method of machine parameters for vector-controlled induction motor drives

A novel and simple offline measuring method for machine parameters of induction motors is presented. The proposed method requires only the knowledge of terminal voltages after the stator current is interrupted. Thus, it can apply to measure machine parameters of induction motor driven by usual PWM inverter. The measuring method is effectively accomplished under any operating conditions including at stationary state. In particular, rotor circuit time constant can be precisely measured without skin effect influence. In this paper, machine parameters obtained from a conventional method and the proposed method are compared. Experiments are performed on a high speed induction motor