Calculation of the bar resistance and leakage reactance of cage rotors with closed slots

Abstract

The paper describes a technique for calculating the leakage reactance and resistance per bar of a cage rotor with closed slots. The method is based on the use of a finite-element field calculation which enables the precise slot geometry to be modelled accurately, and includes the effects of tooth saturation and stator magnetomotive force. The method is illustrated by means of two examples, which are also used to provide a comparison with previous work on similar geometries. The method may be used to generate reactance against frequency and current characteristics, for design office use.