Jawad. Faiz - Electrical and Computer Engineering, University of Tehran

Design of electrical motors normally involves two main stages: i) Preparation of the main dimensions and parameters. ii) Prediction of the performance. At the first stage the main dimensions of the motor, core stack Lfe and stator outer diameter Do, must be chosen. A set of performance conditions such as breakdown torque, desired output and other important parameters must satisfy the international standard requirements or the specific requirements of the electric motor manufacturer. In order to meet the design objectives regarding the performance, the dimensions and the construction types are chosen, and then the cost within the constraints are imposed by manufacturing standard. The output of an electrical machine can be generally expressed as the product of Lfe, Do and a coefficient Co. at the beginning of the design process, the designer does not know a number of the required parameters, which are incorporated in Co, but these parameters may be determined based on the performance calculations. The present paper considers the various factors affecting the choice of iron and copper volume in the motor. It shows how the geometrical parameters can alter the performance of the motor.