High-Frequency Behavior Models of AC Motors

In this paper, we present two high-frequency modeling methods of induction motors for frequency- and time-domain simulation. The first, called ldquoasymptotical method,rdquo consists of deriving the motor model parameters from observation of the variations of the motor impedance with the frequency. The second, called ldquoanalytical method,rdquo consists of deriving the motor model parameters from mathematical resolution of the electrical circuit equations. All parameters of the proposed models are obtained by differential and common-mode impedance measurements. The high-frequency model parameters are measured by using an impedance bridge. We validated the models in both the frequency and time domains. The methods can be used to obtain a high-frequency equivalent circuit of an ac motor.