Efficiency improvement and torque ripple minimisation of four‐phase switched reluctance motor drive using new direct torque control strategy

Abstract

The direct torque control (DTC) strategy is one of the most effective techniques, used to control the switched reluctance motor (SRM) with improved dynamic performance and reduced torque ripple. However, this approach draws a higher source current due to an extension of the phase current into the negative torque region, which lowers the net torque per ampere ratio. This study proposes a new DTC strategy for SRM to overcome this issue by modifying the partition of the sectors and appropriate voltage vector selection. Therefore, the proposed method improves the drive efficiency while minimising torque ripple. To implement this method, a non-linear machine model is developed using the torque and flux characteristics obtained from experimental studies on a four-phase 8/6 SRM. The proposed DTC scheme is implemented on a digital control platform and power loss calculations are performed to evaluate the drive efficiency. Test results show that the proposed DTC method has improved performance in terms of efficiency and torque ripple under various operating conditions in comparison to the conventional DTC strategy.

Advanced Control of Switched Reluctance Motors (SRMs): A Review on Current Regulation, Torque Control and Vibration Suppression

“…The work of [152] points out several key concepts when implementing the DTC method, including the flux-linkage reference value in different operating conditions and the difference between the fluxlinkage vector position and actual rotor position. Improved voltage vectors are used to enhance the torque control performance in [153]- [156]. The speed-dependent flux-linkage reference was presented in [157] to reduce the phase current RMS value.…”

Simulation of Switched Reluctance Motor with an optimized Direct Torque Control minimizing Torque Ripple

“…Yang proposed his paper paying attention to combining fuzzy PID controller instead of hysteresis controller with DTC strategy to decrease the torque ripple. [ [5] In this paper, a 2D model is built for finite element analysis (FEA) to analyze the flux and torque parameters of a 20kW 8/6-pole four-phase SRM. After that, CCC and conventional DTC methods are carried out by MATLAB/SIMULINK software to simulate the motor working conditions.…”

Variable Flux Direct Torque Control System of Switched Reluctance Motor

“…Based on the three-phase asymmetric bridge as the main circuit of the six-phase switched reluctance motor, Liang and Zhang [6] proposed a DTC system suitable for the motor. In [7], the torque and flux characteristics obtained from the study of four-phase 8/6 SRM were used to establish a nonlinear model, and then the proposed DTC scheme was calculated on the digital control platform for power loss to evaluate the drive efficiency. The results show that the efficiency and torque ripple suppression performance of the DTC method is improved compared with the conventional DTC under various working conditions.…”