Equivalent circuit of mush wound AC windings for high frequency analysis

The paper describes a lumped parameter equivalent circuit for the HF analysis of mush wound coils of AC windings. The equivalent circuit takes account of turn-to-turn and turn-to-iron stray capacitances. Dissipative phenomena due to eddy currents in the coil wires and the laminated iron core are also considered. The parameter identification is based on sinusoidal impedance measurements on a test coil. The model of a multi-coil AC stator winding can be easily derived from the proposed equivalent circuit. This model allows one to predict both common- and differential-mode conducted EMI in switching converters supplying AC motors. The simulation results obtained by PSpice are in good agreement with the experimental data.