Combining the principles of sliding mode, direct torque control, and space vector modulation in a high-performance sensorless AC drive

A sensorless induction motor drive is presented, in which the principles of sliding mode, direct torque control and space vector modulation are combined to ensure high-performance operation both in the steady state and under transient conditions. The motor state observer and torque and flux controllers are of the sliding mode type. The inverter is indirectly controlled on the basis of torque and flux control errors using a space vector pulse width modulator. Computer simulations and experimental results confirm the robustness, accuracy, quickness, and low-chattering operation of the drive.