Abstract: A novel speed sensor less adaptive robust control method is proposed to improve the trajectory tracking performance of induction motors. The proposed design employs the so called vector control (or field oriented control) theory for the multilevel inverter fed induction motor drives. The inverter design is based on three- level Neutral Point Clamped (NPC) inverter with hysteresis current control technique. Two Mamdani type fuzzy logic controllers are used; one as speed controller and the other is in Luenberger Observer in order to estimate the actual rotor speed. The Particle Swarm Optimization algorithm is used to optimize the parameters such as membership functions, normalizing and de-normalizing parameters of fuzzy logic controller. The performance of proposed scheme is investigated under various load and speed conditions. The simulation results show its stability and robustness for high performance sensor less drive applications.

Keyword: Field Oriented Control (FOC), Multilevel Inverter, Hysteresis Current Control, Particle Swarm Optimization (PSO), Fuzzy Logic Controller.