Sensorless direct torque and flux control for matrix converter-fed interior permanent magnet synchronous motor using adaptive sliding mode observer

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. The adaptive sliding mode observer simultaneously estimates the stator flux, speed and rotor position. A permanent magnet flux estimator is integrated with the observer to compensate the effect of inaccurate PM flux on the estimation error. 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 overmodulation 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, while maintaining constant switching frequency and fast dynamics. Experimental results are shown to illustrate the effectiveness of the proposed sensorless DTFC-ISVM matrix converter IPM motor drives.