Generator Excitation System Modeling And Parameter Identification

As the development of the electric power system, the scale of the network becomes considerably large, and interconnected network across areas emerges. The interconnectered network causes obvious changes in calculation and analysis of the stability. And fundermental data of the accurate model and parameters of excitation system of generator, speed-governing system of steam turbine and the effects of the dynamic features are needed to considered in these works.In this thesis , the modelling and identifition types and techniques of the large generator unit are summarized, the research achievements on the modeling and idenfication of the generator and it's parameters in home and abroad are analized in detail , the difference and similarity and their relation are compared ,the basic definition of the excitation system and their values in per unit are given . On the fundment of detailed study of the hardware components and software programming of excitation system , detailed method , experience, and principles of models for power system stability studies according the data of field-testing are given in the paper. The model and parameter accuracy are essential for excitation system modelling and parameter idenfication, and the criteria of testing the vadlity is given too.Most excitation system of generators now in use in our power system can be simulated with the exsisted mathmatical models. The excitation system, with the same models, will have different parameters and their adjusting quantity vary in different way. One of the most important tasks of field-testing is to determine the parameters of the excitation system model. In this paper ,the method to determine the excitation system parameters is devised : to simulated-AVR(automatic voltage regulator) , beginning with consideration of an apporiate per unit system , then describe models for the various components , and finally present complete models fo r selected types of excitation systems , to AVRbased on computer , using the method of curve-fitting of the time-domain response of the whole control system.When there are no the exact same model in the program of power system stability computing as the oriental excitation system model ,the oriental model should be transferred into the most near one to the computing program. Having identificated the model and determined the parameters ,the correcting work should be done. To the model and parameter of the generator excitation system , little-disturbance verification and large-disturbance verification should be carried on. The method and steps of each verification are given in the thesis.Finally, the paper indicate the field-testing method to model and identificate the parameters of the large-scale synchronous generator is correct by providing an practical example from testing scheme, data dealing to simulating. At the same time , there are many work to pefect the method and the use will be broad.