Dynamic Vector Modeling of Three-Phase Mutually Coupled Switched Reluctance Machines with Single dq-Quadrant Look-up Tables

Abstract

This paper presents a dynamic modeling method for a 3-phase mutually coupled switched reluctance machine (MCSRM) considering spatial harmonics and saturation. The conventional modeling methods of MCSRMs are based on 3D look-up tables (LUTs), where the phase flux linkages are considered as state variables. These 3D LUTs describe the phase currents with respect to phase flux linkages and rotor position. The 3D LUTs represent two dq quadrants and are obtained from finite element analysis (FEA) by multi-phase excitation where the excitation currents cover two quadrants in the dq synchronous reference frame. The LUTs used in the proposed method represent the phase current and electromagnetic torque as vectors. The magnitude and the angle of these vectors are represented by the sine and cosine Fourier coefficients. Hence, rotor position is not an input to the LUTs and the proposed method uses 2D LUTs. Additionally, the flux linkages in the four dq quadrants possess symmetry for MCSRMs. Therefore, LUTs corresponding to only one dq quadrant are required. The single-quadrant based LUTs reduces the number of FEA steps and the size of the LUTs by 50% compared to the two-quadrant LUT based models. Finally, the proposed method is validated using FEA and experiments for a 12/8 MCSRM.

Modeling and Evaluation of Mutual Coupling Effect in Conventional Switched Reluctance Machines Using Space Vector Representation

“…The derivative model is not preferred as it amplifies the simulation error. Hence, these LUTs are usually inverted, in this case, the flux linkage is calculated from the integration, and the model is considered to be an integral model [1], [28]. Gridfit Matlab function tool is used in [28] and it is used in this paper.…”

“…Hence, these LUTs are usually inverted, in this case, the flux linkage is calculated from the integration, and the model is considered to be an integral model [1], [28]. Gridfit Matlab function tool is used in [28] and it is used in this paper. The inversion of the LUTs in ( 3) is done at each rotor position where the 3D LUTs are represented as 2D LUTs (λ lag = f λ lag (i lag , i lead ) & λ lead = f λ lead (i lag , i lead )).…”