Sensorless direct torque and flux controlled IPM synchronous machine fed by matrix converter over a wide speed range

This paper proposes a new sensorless direct torque and flux controlled interior permanent magnet synchronous machine drive fed by a matrix converter. Closed-loop control of both torque and stator flux is achieved by using two PI controllers. The input power factor and output voltage vector are regulated with the indirect space vector modulation. An adaptive observer is used for joint stator flux and rotor speed estimation. At low speeds, the observer is enhanced by introducing a speed correction term derived from the error signal of HF signal injection for stable operation down to standstill. The stator resistance variation is compensated with the current error signal. The operating range of the drive is extended into high speed region by incorporating field weakening. The proposed sensorless drive exhibits high dynamic and steady-state performances over a wide speed range. Experimental results confirm the effectiveness of the proposed method.