Fuzzy logic approach for energy efficient voltage controlled induction motor drive

The tracking of maximum efficiency point of a lightly loaded induction motor is generally obtained using the search technique which is time consuming and the machine is subjected to many step changes of voltage which is undesirable. This paper presents a novel technique for energy efficient operation of voltage controlled induction motor drive using fuzzy logic principles. In the proposed method, the time required to converge to the best efficiency point of the drive is minimum and the machine is subjected only to one step change of voltage, irrespective of load change. The fuzzy logic variables and the fuzzy rules are formulated based on experimental investigations. The rule base for the optimum voltage identification is generated in the entire operating range of the motor with a no priori knowledge of the machine parameters. The fuzzy logic estimator is then used for performance optimization of induction motor and the simulation results are presented. The simulation results demonstrate the efficiency of the fuzzy logic estimator based voltage controller