Grey Prediction Control And Extension Evaluation Of The Generator Governor Control System

With the increasing expansion of modern power system, as the basis to ensurethe stable operation of power grid, the research of power system stability has beenpaid more and more attention. To address the stability of power system under a big orsmall perturbation, this document started with the governing system, proposes acontrol method of synchronous generator speed control system based on grayprediction theory, then carries out computer simulation about the control effect, andalso carries out evaluation analysis work for the control performance of the methodbased on extension principle.This paper describes the function and importance of generator speed systembriefly, and introduces the development history and research status of synchronousgenerator speed control system, then discusses the application of various controlstrategies in the speed control system, thus have one conclusion that due to thenonlinear and time-varying of complex power system, it is not very perfect forvarious control methods, so study on a new control method of speed control systemwhich is more advance is very necessary.This paper uses a compound control method which combines grey predictionand PID control technology. firstly, the grey prediction algorithm is written usingMATLAB language; then one model of improved GM(1,1) is proposed based on theclassical grey GM(1,1) model, and confirms its “predict” feature by simulation. Bycombing PID control technology and grey prediction link, the grey prediction PIDcontroller is designed, the simulation results of simple system show that greyprediction control can improve the dynamic characteristic of system effectively, andrealize prior-control to “prevented accidents before they occur”.As a basis for the study, this paper describes the working principle and controlmethods of the generator speed control system briefly, and introduces themathematical model of hydro-generator governing system in detail, includinggovernor model, hydro-turbine and its diversion system model and synchronous generator model known as typical second-order single-machine infinite system.Using these models established the simulation model of hydro-generator governingsystem in the MATLAB/Simulink software. Grey prediction PID control isintroduced in the synchronous generator governing control system; thecorresponding simulation model is established using MATLAB. Then we researchthe system’s transient process under a given step signal input and a disturbancesignal input, the simulation results suggest that the grey prediction control canreduce the overshoot and adjustment process time effectively, and allow the systemcome into a stable state quickly. Compared with the conventional PID controller,control effect of the grey prediction PID control is more effective.To evaluate the control performance of grey prediction PID control, in thispaper, the characteristics of the system’s dynamic performance such as overshoot,peak time, rise time and adjustment process time are regarded as the evaluation index,and takes all kinds of factors which affect the system performance into account in toconsideration, using extension method to compare multiple objects throughhorizontal comparison The index value is obtained by the simulation results, andthen using these value establishes the matter-element model. Using the knowledge ofcorrelation function to evaluate and compare the results of the grey prediction PIDcontrol and PID control. The results show that, the control effect of the former isbetter than the latter, and verify the validity of grey prediction control.