Sensorless direct torque and flux control for matrix converter IPM synchronous motor drives using adaptive sliding mode observer combined with high frequency signal injection

This paper presents a speed and position estimation method for the sensorless direct torque and flux control scheme for matrix converter driven interior permanent-magnet synchronous motor. This method is based on an adaptive sliding mode observer that is enhanced with a high-frequency signal injection technique at low speed and standstill. The direct closed-loop control of both torque and stator flux are achieved using two proportional-integral controllers and indirect space vector modulation with a new over modulation strategy. The system is characterized by low torque and flux ripples, unity input power factor, sinusoidal input/output currents, inherent bidirectional power-flow capability and good speed sensorless control performance over wide speed range, including zero speed, while maintaining constant switching frequency and fast dynamics. A new compensation method is proposed to correct the effect of L_q saturation under load. Experimental results are shown to illustrate the effectiveness of the proposed sensorless DTFC-ISVM matrix converter IPM motor drives.