Design and development of open loop CGSM for SR motor

Abstract

This paper presents development and implementation of open-loop current gradient sensorless method (CGSM) for low frequency PWM controlled switched reluctance motor. Prototype SRM drive is developed with split DC converter and low frequency PWM controller. New open loop CGSM is analyzed for constant speed drive. Performance analysis of proposed CGSM with low frequency open-loop and closed-loop PWM control is discussed. Proposed method eliminates the need of phase-lock-loop (PLL) and speed feedback in CGSM which reduce the cost and complexity of the drive. Both simulation and experimental results are presented for validation. Opal's RT-Lab is used as hardware-in-loop controller for easy and flexible implementation of controller and sensorless scheme.