Computer representation of brushless excitation system

Abstract

A computer model of brushless excitation system for lar~e alternators has been developed. The model is based on detail understanding of principle of its operation under varying terminal conditions. The exciter-alternator is simulated by fivewinding representation as suggested by Canay and the rectifier unit 1S modelled on the basis of analytical . express10ns representing different mode of operations. Each module of. the brushless excitation system has been joined together to form a complete model which can easily be rearranged to simulate a particular condition. Responses of brushless excitation system under both transient and steady state condition have been simulated. The result of the developed model is compared with test response and found to have good agreement. The outcome of the model 1S also judged against IEEE model and the model developed is ranked to be a superior one. In this respect the shortcomings of the IEEE model are also pointed out. The work presented in this thesis would form a basis of modelling alternators having brushless excitation systems.