Current Gradient Sensorless Method with Phase-Lag Calibration for Switched Reluctance Motors

The current gradient sensorless method is a position detection technique for switched reluctance drives. The method is adaptable and easy to operate. However, this method must filter the current, that causes the phases-lag and notable error in position detection, especially when the rotor runs at high speed. This paper presents an approach that first calculates the phase-lag angle of the low-pass filter to calibrate the detected position signal and then improves the detection precision of the current gradient sensorless method. The experimental results demonstrate the functionality of the proposed method.