Inductance test method of permanent magnet synchronous reluctance motor for electric vehicle

Because the saturation and cross-magnetization of permanent magnet synchronous reluctance motor (PMSRM) in the operating area of electric vehicle vary greatly, there is no ideal testing equipment and method to accurately obtain the inductance parameters of d and q axes in the working region of the motor. A large number of experiments are needed to achieve optimal control. Therefore, By formula derivation and test method research, two suitable methods for this kind of motor are proposed in this paper. One method is static testing when the motor can not be driven. The inductance of the motor was obtained by measuring the voltage and current waveforms. Then the errors of calculation results were dealt by the least square method, which effectively solves the problem that the asymmetry of the magnetic circuit and the cogging groove cause fluctuation of the calculation results. Thus, the test accuracy is improved. Another method is to use common testing equipment to solve the problem of measuring the power factor angle of the motor in operation. Through testing the electrical parameters of the motor in the working region, the inductance parameters under different working conditions were calculated. Finally, the inductance parameters measured by these two methods and volt-ampere method were applied to the same controller (maximum torque per ampere, MTPA). The applicability of the two methods is verified by comparison. © 2021, Harbin University of Science and Technology Publication. All right reserved.