Model-Based Spatial Harmonics Vector Compensation Method for Three-Phase Mutually Coupled Switched Reluctance Machine With Sinusoidal Current Excitation

This paper presents a spatial harmonics compensation method for mutually coupled switched reluctance machines (MCSRMs) with sinusoidal current excitation. The regulation by linear controllers to achieve sinusoidal currents in MCSRMs is challenging due to the substantial presence of spatial harmonics. The standard vector control with using Proportional-Integral controllers cannot effectively suppress the spatial harmonics of the current waveform due to the bandwidth limitations. In the proposed method, the essential voltage harmonics are added to the fundamental voltage component to create sinusoidal currents. The voltage harmonics are calculated from the flux linkage harmonics where voltage and flux linkage harmonics are represented as vectors in terms of Fourier coefficients. The Fourier coefficients of the flux linkage are function of direct-and quadrature-axis currents. Hence, they are in the form of two-dimensional look-up tables (LUTs). The used LUTs in the proposed method are independent of rotor position and they are obtained from the finite element analysis (FEA) model. The proposed spatial harmonics compensation method is validated using FEA and experiments for a 3-phase 12/8 MCSRM at generating and motoring modes of operation.