Determination of saturated parameters of PM motors using loading magnetic fields

The precise knowledge of parameters is of critical importance for the correct performance prediction and design optimization of permanent magnet (PM) motors. A method for numerical calculation of the saturated direct and quadrature reactances X_d, X_q and excitation voltage due to magnets E₀, related to any arbitrary operational case, is proposed. Based on the evaluation of internal voltage from nonlinear load magnetic fields by finite-element method, the parameters X_d, X_q, and E_O are obtained. The proposed procedure has been applied to analyze a laboratory 25 hp PM motor and determine its saturated parameters. There exists a close agreement between the simulation and experimental results.