Research on DTC system with variable flux for switched reluctance motor

Abstract

When switched reluctance motor(SRM) is in the status of the traditional direct torque control(DTC) system, due to the high saturation nonlinearity of the electromagnetic relationships of switched reluctance motors, the torque ripple and the stator phase current are larger. In order to resolve the above problems, through the analysis and deduction for SRM flux model and the influence of characteristics of flux and speed on torque ripple, this paper presents a variable-flux control strategy with the three closed-loop structure based on the critical flux supersaturated speed. And a DTC system of SRM with variable flux and three closed-loop is built up in Matlab/simulink. Moreover, the DSP hardware experiment platform based on the TMS320F2812 is established to validate the performance of the improved algorithm. The simulation and experimental results show that the new scheme has an obvious effect on torque ripple reduction, and the three — phase stator current is obviously reduced, which greatly reduces the stator winding copper consumption during the operation of SRM. Moreover, the improved system has good system stability.

Keywords

• critical flux supersaturated speed
• direct torque control
• switched reluctance motor
• three closed-loop
• variable flux