Speed Tracking nonlinear Control using Second order Luenberger observer of Five Phase Permanent-Magnet Synchronous Motor Supplied by a Flying Capacitor Multi-cellular Inverter

This paper proposes a speed and position sensorless nonlinear sliding mode control (SMC) scheme of a five-phase permanent magnet synchronous motor (FP-PMSM) drive supplied by a Flying capacitor multi-cellular (FCMC) inverter. The SMC strategy is developed using an integral switching surface, where the saturation function is used as the switching function instead of the signum function to reduce the chattering problem in the SMC strategy. In order to extract accurate rotor position and reduce position estimation error in both forward and reverse rotation of the FP-PMSM drive, a second-order Luenberger observer is proposed for simultaneously estimation of the rotor position and the motor speed. The proposed sensorless control has advantages of simple design and robust estimation performance at a wider speed range, where the estimation accuracy is obtained even when the drive operates at reverse rotation. The validity of the proposed sensorless control has been successfully demonstrated with simulations on virtual platform.