Speed Sensorless Vector Control of Cascaded Inverter for Asynchronous Motor

According to speed sensorless vector control of Asynchronous motor for Cascaded high voltage inverter, a model reference adaptive system (MRAS) implemented in two phase rotating reference frame was studied to identify the rotor speed of an asynchronous motor. To eliminate the inherent limitations of MRAS in two phase stationary reference frame, the reference model and adjustable model used in this MRAS scheme are composed of an improved rotor flux voltage model and rotor flux current model in two phase rotating reference frame respectively. Simulation and experimental results show that the vector control system can estimate the flux and speed with good accuracy, and run with good static and dynamic performance in start, speed regulation and steady operation.