Design And Simulation Research Of Optimal Excitation Control System Based On Parameters Identification Of Synchronous Generator

Generator excitation control has become an extremely important measure toimprove power system stability and the dynamic quality. Both static stability andtransient stability can be effectively improved by applying the appropriate control forgenerator excitation.It is of great significance for safe and stable operation of system toresearch and design of the efficient synchronous generator excitation control system.Generator excitation control is very to power system stability,but detailed andaccurate generator model parameters are required for research and application of controlstrategy. Synchronous generator parameters and their accuracy have a direct influenceon excitation control system.It is very necessary to identify synchronous generatorparameters before design of synchronous generator excitation control system.This paper discussed the research situation on the method of synchronousgenerator parameters identification and excitation control in detail and systematicallyintroduced mathematical model and basic theory that this paper required.In order to avoid solving complex differential equations, simplify parameteridentification method and improve the efficiency of identification,this paper deducedsynchronous generator electrical parameter identification model in detail based on Parkmodel, on which all the variables can be measured. According to the parameteridentifiability principle,this paper analyzed the identifiability of electrical parameteridentification model and mechanical parameters identification model. It is pointed outthat both the electrical parameters and mechanical parameters are uniquely identifiableunder the circumstances of the steady-state equation being the additional condition andmotive torque approximately unchanged respectively. Synchronous generator parameteridentification strategy was put forward, and then electrical and mechanical parameterswere identified by the nonlinear least square method and integral least square methodrespectively. The test results with MATLAB showed that the model presented in thispaper is correct,feasible and valid.After obtaining the parameters of the synchronous generator, this paper presentedlinear state-space equation for a single machine to infinite system based on Parkmodel,which was used for the design of optimal excitation control law. Applying thisequation on the basis of optimal control theory,a new excitation controller wasdesigned,in which the terminal voltage, active power, reactive power, angular velocity and angle were the feedback. Load angle and reactive power were introduced toexcitation control law,which are closely related to stability and quality. At the same time,in order to improve the terminal voltage regulation accuracy, the integral control wereintroduced the excitation control law. The outcome of MATLAB simulation indicatedthat compared to the other methods, excitation control the paper presented caneffectively improve the power system’s stability in large and small disturbance,as wellas in voltage regulation precision.