Optimum design of a three phase squirrel-cage induction motor based on efficiency maximization

Abstract

Efficiency maximization of a three phase squirrel-cage induction motor with constraints imposed upon the performance characteristics of the motor is carried out. Initially a computer program, based upon the numerical and analytical design procedures, has been developed for the design of a three phase squirrel-cage induction motor and its calculated performance has been validated against the performance of the squirrel-cage motor of standard commercial design. The output of this program is the input of the optimization program. A non-linear optimization routine for the motor design is used and this optimized design is compared with those obtained using other optimization procedures and a more complicated optimization procedure. The pattern search method of Hooke-Jeeves is used successfully, by direct imposition of constraints, for optimum design of a 5 h.p. motor. The results of the optimization consisting of variations of the performance conditions and relative variations of these characteristics, are then compared with the results of the optimization based upon the Han-Powell procedure, simple and modified Hooke-Jeeves methods. This comparison indicates that, in spite of different optimization variables and routines used, the relative variations of the performance characteristics are similar.