Reduced Torque Ripples in 8/6 Switched Reluctance Motor by Fuzzy-Logic Controller

Abstract

Switched Reluctance Motors (SRMs) have a number of features that make them interesting for use in electric vehicles, including their simplicity, high reliability, high speed range, and lack of permanent magnets. But due to the nonlinear magnetic behavior and discontinuous phase excitation of an SRM, it can lead to high electromagnetic torque ripple, leading to vibration, acoustic noise and loss of drive performance. A fuzzy logic based torque ripple reduction control strategy for 8/6 SRM is presented in this paper. The proposed drive is modeled in MATLAB/Simulink with a dc source, asymmetric converter, rotor position sensor, and a switching table with a hysteresis current controller. To improve the phase current regulation a Fuzzy Logic Controller (FLC) with two inputs (speed error, change in speed error) is used to produce the reference current. Each of the input is assigned seven triangular membership functions, and the total numbers of fuzzy rules are 7×7 = 49. The rotor position is then used for phase switching sequence determination and the hysteresis controller keeps the phase current within the band. The proposed controller is simulated and tested using the simulation results to assess the performance of the controller in terms of torque ripple, speed response, and phase current characteristics. The proposed approach offers a smoother torque production and better dynamism in the SRM driving. The proposed FLC-based SRM drive successfully reduces torque ripple, improves torque smoothness, has better dynamic response and produces stable speed control when compared to conventional control schemes. The proposed method provides a simple, reliable and computationally efficient control solution which is suitable for enhancing the overall performance of SRM drives, and can be used in the advanced electric propulsion and industrial motion control applications.