Direct position control for ultra-high speed switched reluctance machines based on non-contact optical sensors

Abstract

The maximum speed of ultra-high speed switched reluctance machines (SRMs) is limited by commercial rotary encoders due to mechanical considerations. In this paper a novel direct position control for ultra-high speed SRMs based on non-contact optical sensors is proposed. The paper presents the use of reflective optical sensors to detect the relative position between the rotor and the stator so as to control the on and off states of the switches directly through the analog output trigger signals generated from the optical sensors. The proposed control has many advantages such as versatility, virtually no speed limitations, simplicity and low cost. This technique allows for precise control of SRMs to speeds beyond 1 million rpm.