Research on the switched reluctance machine drive system for electric vehicles

The drive system of switched reluctance machine (SRM) for electric vehicles (EVs) is studied. Based on the analysis of the three basic control methods, i.e. current chopping control (CCC), voltage PWM control (VPWMC) and angle position control (APC), three different control methods for low speed, medium speed and high speed are proposed to widen the speed range. The turn-on and turn-off angles are changed in real time to improve the system efficiency. In terms of hardware, voltage, current, temperature sensing circuits and output signal logic synthesis circuit are designed. The flow diagram of main program and subroutines are designed according to the proposed control strategy. The 7.5 kW SRM drive system for electric vehicles is built and speed waveforms and current waveforms in different speed sections are compared and analyzed. Experimental results indicate that the three-section drive control methods can achieve good start, acceleration and deceleration performance, which is well applied to the EVs drive system.