Research Of Excitation Control For Synchronous Machines With Brushless Excitation System

The rotor winding of Synchronous Machines with Brushless Excitation System is excitedby ac exciter.which leaves out the brush and slip ring. This exciting mode has nocommutation spark, and is suitable for operation in hazardous working conditions. At thesame time, it also improves the insulation of the motor life. saves the maintenance work, andimproves the reliability of excitation system. The excitation source is taken from the motorshaft, which gets a reliable guarantee for the stability of the excitation source. The stand orfall of the design for the generator excitation control system directly affects the performanceof the generator and power system.Combined with domestic and foreign literatures, this paper introduces the developmentof brushless excitation generator as well as the status quo, development and status quo ofexcitation system control method. Then establishes of a synchronous generator three-phasenatural coordinate system and two-phase rotating coordinate system of the mathematicalmodel of generator on the basis of the introduction the working principle of the brushlessexcitation generator and per unit system. Then establishes the mathematical model of acexciter.This paper conducts a comprehensive study of the excitation control system for thebrushless excitation generator. Based on the principle of fuzzy control method is introduced,the method conventional PID control in combination with fuzzy control applies to thebrushless excitation generator excitation control system. Then introduces in detail the designmethods and steps of the excitation control system. For the problem of large time constant ofthe ac exciter, this paper adopts the method of time constant compensation, improve theresponse speed of the control system.Using the mathematical model of brushless excitation generator, the paper builds thesimulation model of brushless excitation generator in the Matlab/Simulink software. whichmakes a more accurate mathematical model to the brushless excitation generator excitationcontrol in design. Then conducts a simulation research on the designed model with the fuzzyPID excitation controller. The results demonstrates the validity of brushless excitationgenerator model, as well as the design of fuzzy PID controller has better static and dynamicperformance, is a kind of more excellent excitation controller.