Operating cost optimisation of speed-changing induction motors

A computer program is developed for the optimisation of single-winding, dual speed induction motors using least pth approximation method combined with Rosenbrock technique. The overall economy in designing the motors for minimum operating cost is brought out with examples. Optimisation results show that the performance values, as well as manufacturing cost, are essentially the same for a dual-speed motor of a given kW rating and pole combination designed for various duty cycles. The treatment of independent variables, and constraint specifications and the logic incorporated in the program are discussed.