Radiated EMI modeling and performance analysis for PWM PMSM drive system based on field-circuit coupled FEM

The radiated electromagnetic interference (EMI) behavior may have a negative impact on the machining accuracy of grinding machines. Therefore, this paper focuses on radiated EMI generated by an ultra-precision pulse width modulation (PWM) permanent magnet synchronous motor (PMSM) drive system. The excitation for the radiated EMI model, the common mode (CM) ground current at the output terminal of the converter, is obtained by simulating its conducted EMI model. The reasonable simplified FE models for the converter frame, the shielded power cable and the motor frame are established. Additionally, an equivalent circuit macro model of the CM impedance of the three-phase PMSM windings is obtained by using impedance measurements, the vector fitting method (VFM) and the fast residue perturbation method (FRPM). Finally, the 3D time harmonic field-circuit coupled finite element method (FEM) is employed to evaluate the radiated EMI.