ABSTRACT
The recent energy crisis has led to renewed interest in induction generators as sources of electrical power . This is due to certain advantages they possess. For example, they are of simple construction ; of low cost and rugged. Moreover, they can be easily coupled to many types of motive sources , thus they can be utilised in rural areas of developing countries. In such situations the reliability of the self excitation process is of paramount importance. The survey of previous works on induction generators indicated that most of the authors are concerned with, steady-state conditions , well after the machine has built-up. Furthermore, there is no adequate model that could be used to study the transient build-up stage. The aim of this work was to develop such a model with a view to study the effect of machine parameters and other external effects. The machine is modelled in a quasi-stationary d-q reference frame in which the mutual inductances are considered non-linear . The derived machine equations are of the form already developed by other authors [40,65] for motor operation Appropriate changes are then carried out in order to investigate the induction generator conditions of excitation. A computer program was then developed using PASCAL language in order to study various excitation methods ,with a unique attempt to study the possibility of excitation from the rotor side. The model indicated a need for further work in the area of excitation from the rotor side. Using the results of the simulations, suggestions are then given on how to improve the reliability of the self-excitation process.