A novel direct instantaneous torque control strategy in permanent magnet-assisted switched reluctance motor based on optimization of conduction angle

Abstract

A novel direct instantaneous torque control (DITC) strategy based on optimized conduction angle is proposed with the aim of reducing the torque ripple of permanent magnet-assisted switched reluctance motor (PMa-SRM) during the two-phase exchange (TpE) region in this paper. Firstly, according to the inductance characteristics, the TpE region is subdivided into TpE I and TpE II region where the turn-off angle is acted as the region separation point, and the corresponding torque hysteresis strategies are formulated in different regions. Secondly, K-fold extreme learning machine (ELM) method is used to optimize the turn-on angle in order that the current of incoming phase can quickly increase to maintain torque balance. In order to make full use of the ability of torque generation of two adjacent phases, the position where the torque of adjacent phases is equal is used as the turn-off angle of incoming phase. Finally, a 6/20 PMa-SRM prototype is simulated and verified. Compared with the conventional DITC strategy, the novel strategy not only diminish torque ripple and negative torque under different operating conditions, but also expands the operating range of the motor and improves the motor efficiency.

Keywords

• Permanent magnet-assisted switched reluctance motor
• Direct instantaneous torque control (DITC)
• Extreme learning machine (ELM)
• Torque ripple
• Turn-on angle
• Turn-off angle