Travelling waves in induction machines: input impedance and equivalent circuits

The problem of travelling electromagnetic waves in multiregion induction machines at power frequencies is examined. Using the concept of surface impedance, a method is derived whereby equivalent circuits can be established in a systematic manner. A method of determining levitation force from a knowledge of the equivalent circuit is developed. Calculation of input and output power is simplified using the approach outlined. The ferromagnetic portions of the multiregion system are assumed to have constant permeability.