Induction Motor Optimum Design, Including Active Power Loss Effect

The paper presents the optimum design of three-phase squirrel-cage induction motor on the basis of minimizing the annual cost of the motor. The annual cost is the sum of the annual interest and depreciation of the motor active material costs, annual cost of the active power loss of the motor and the annual energy cost required to supply such power loss. The objective function of the nonlinear optimization problem is deduced in terms of twelve independent motor design variables. These variables are also used to formulate seven important motor performance indices which act as inequality design constraints. The Rosenbrock nonlinear optimization technique is used for solving the optimization problem and is illustrated by a given example. The obtained results are given in comparison with those of an optimally designed motor, designed on the basis of minimizing its active material cost only.