the use of elg for stand alone power system frequency control is investigated in this thesis. characteristics of a stand alone power system with pcr-elg are presented. dynamic simulation of the system is developed using simulink/simpowersystems and is verified by comparing the simulation results with experimental results in the literature. the simulation results show that terminal waveforms of the synchronous machine with controller rectifier load are highly distorted. pulses in phase voltage caused by negative current through thyristors affect rectifier control if appropriate snubber/filter is not imposed. based on the simulation results, pcr-elg control with feedback loop is designed. the control results are compared with those of the system having only normal governing and excitation systems. the results show that pcr-elg can provide much better frequency control for a stand alone power system than normal governing and excitation control.