Multicriterial optimisation of squirrel-cage induction motor design

The task of finding an optimal induction-motor design is defined as a discrete multicriterial optimisation problem. An approach to solving this problem through two-level optimisation is described. A bicriterial problem is solved by the assumption that all optimisation variables are continuous. Criterial functions in the example are material and operating costs of the motor. The possibility of applying two methods (multipliers and constraints) is considered and both these methods are employed in the optimisation process. Corresponding scalar optimisation problems are solved by means of a quadratic approximation method. An analysis of obtained optimisation results is performed, with the major conclusions that two local compromise solution sets exist and that the global solution sets exist and that the global compromise set in the decision space is not continuous. The computational model (more sophisticated than in the majority of other works dealing with the optimisation of an induction-motor design) and the synthesis program are briefly described. The results of design calculations are analysed mainly for two optimal solutions determined for minimal operating and material costs, although intermediate results are also presented