Loss Reduction Method Based on Single-Pulse Mode in V/f Control for Switched Reluctance Motors

抄録

This paper proposes a loss reduction method based on the single-pulse mode with a freewheeling period in V/f control for switched reluctance motors (SRMs), specifically targeting the high-speed region beyond the base speed. The proposed method is implemented using the pulse-width modulation (PWM) module of a general-purpose microcontroller, enabling an operation that closely mimics traditional single-pulse behavior while minimizing switching events. This method results in steeper rising and falling edges of the current waveform, contributing to reduced losses. Compared to conventional V/f control based on sinusoidal voltage drive, the proposed method shortens the conduction period in the negative torque region, thereby decreasing copper loss. Additionally, by introducing an appropriate freewheeling period, the voltage-time integral (i.e., flux) is reduced, leading to a reduction in iron loss. The proposed method consists of three main components: (A) a parameter determination strategy to enable single-pulse mode within the V/f control, (B) an efficient control technique tailored for freewheeling operation, (C) a method for suppressing beat phenomena caused by conduction angle errors in discrete-time control systems. Experimental results demonstrate that the proposed approach reduces copper loss by 21.4% and iron loss by 5.7% under base-speed and rated-torque condition, confirming its effectiveness.