**4.3. Problem formulation**

A very important problem in the induction motor design is to select the independent variables otherwise the problem would have been very much complicated using too many variables (Thanga, 2008). Therefore variables selection is important in the motor design optimization. A general nonlinear programming problem can be stated in mathematical terms as follows.

Find � = (��� �� �..��) such that ��(�) is a minimum or maximum ��(�) 0, � = �� �� � �

�� is known as objective function which is to be minimized or maximized; ��'s are constants and ��'s are the variables. The following variables and constraints (Thanga, 2008) are considered to get optimal values of objective functions.
