| Abstract |
A new variable structure, direct torque controlled, sensorless induction machine drive is presented, in which the principles of Variable Structure Control (VSC) and Direct Torque Control (DTC) are combined to ensure high-performance operation, both in the steady state and under transient conditions. The drive is directly controlled on the basis of torque and flux errors, using Variable Structure Control and Space Vector Pulse Width Modulation. Classical DTC transient merits are preserved, while the steady-state behavior is significantly improved. The novel full-order state observer is of Sliding Mode type and it does not require the rotor speed adaptation. A new stator resistance adaptation scheme is proposed. The proposed solution allows wide speed range sensorless operation, including very low and zero speed, full load. Extensive experimental results confirm the robustness, accuracy, quickness, and low-chattering, sensorless operation. |
