Efficiency Optimization of Induction Motor Using a Fuzzy Logic Based Optimum Flux Search Controller

Induction motors are, without any doubt, the most used in industry. Motor drive efficiency optimization is important for two reasons: economic saving and reduction of environmental pollution. In this paper, advantages of using fuzzy logic in steady-state efficiency optimization for induction motor drives are described. Experimental results of a fuzzy logic based optimum flux search controller are presented. There are so many speed control techniques available, like scalar control, vector control, sensor less control etc. Due to coupling effect, the scalar control has inferior performance and vector control is a method of speed control in which both magnitude and phase angle of current can be controlled. In vector control, the presence of speed sensor at shaft decreases the reliability and ruggedness. For transient states, a new original idea is introduced: a fuzzy logic based controller, actuating as a supervisor, is proposed to work with reduced flux levels during transients to optimize efficiency also in dynamic mode. Two different rule tables are designed, for torque transitions and for reference speed changes. With this controller, efficiency can be improved in transients, and also search controller convergence speed is increased. In my work efficiency optimization of induction motor using fuzzy logic controller was carried out using Matlab.