A novel modular power converter for SRM drive

Abstract

In this paper, a novel modular power converter for four-phase switched reluctance motor (SRM) is proposed. Firstly, a converter with motor phases grouped in pairs which share one common converter phase is introduced. This discrete-type converter is equivalent to the asymmetrical half-bridge converter (AHBC) in terms of the number of semiconductor components and functionality. The common converter phase concept enables modularization using two standard, commercially available six-pack IGBT modules, thus simplifying mass production. Compared to existing modular topologies, the proposed modular converter has the advantage of enabling an overlap of current pulses, which is a key feature for the SRM performance at elevated speeds while retaining a minimal number of standard power switch modules. In addition, owing to inherent operating regimes, the proposed modular converter enhances the motor performance over almost the entire range of the exploitation characteristics compared to AHBC and existing modular topologies. The advantages of the proposed modular topology were determined by means of finite element method (FEM) simulations. Experiments confirm the conclusions obtained from FEM analysis and verify the feasibility of the proposed modular converter.