Reform Of Excitation System For Plant #8 Of Bai Yu Tan Hydropower Power Station

The main research of this paper is the design of the excitation system for Bai Yu Tan #8 power station.Refering to the frequent problems of the original excitation system,a new excitation system was designed after cofirm the excitation system of the control object and control target.Through refering to works at home and abroad,as well as to analysis the problems of the original excitation control system existing in the equipment,the paper choose a digital self-shunt excitation regulator which is suitable for the excitation control system.We put forward an AVR + PID + PSS2 A excitation suitable for small and medium-sized,it is based on the technical requirements for environment and the excitation control system.This research has been completed design the hydropower wheel generator and testing experiment for from excitation excitation control system.Firstly,this paper introduced that the excitation system has a great influence to the stability of the terminal voltage,the distribution of reactive power and the stability of the power system.At the same time,it is briefly describe the situation of the development of the domestic and foreign exciter and the background of the design of the #8 engine excitation system.The feasibility of the #8 excitation was analyzed based on computer excitation control technology.The control scheme of excitation system has been determined by comparing the excitation method used in generator sets with several typical excitation system control methods.Secondly,this paper designed the system power unit.The excitation transformer was the first part work.Then it is introduces the principle of rectifier,which is mainly composed of single or multiple three-phase full controlled rectifier and it is auxiliary equipment.In this paper especially use the pulse train instead of the traditional pulse wide,it is significantly improving the reliability of thyristor trigger conduction and guarantee the realization of the generator excitation function.In this papaer,the method of average the current is used to effectively realize the high horizontal current coefficient.Lastly,it is describ the excitation unit of excitation system.Thirdly,the hardware and software for the exciter was designed.In this paper the hardware is includ the main control panel board,which adopts the embedded mainstream ARM + FPGA system,I/O interface board,open board and out board,then the basic principles of several A/D converters and D/A converters was designed,it is also includ analog signal acqusition and output interfaces.At the same time,this paper analyzes the composition unit of excitation controller which is includ measurement comparison unit,adjustment unit,integrated amplification unit and phase shift trigger unit.In this paper the software mainly designed for the state measurement,adjustment,excitation given management,excitation system stabilizer(ESS)and power system stabilizer(PSS).In this paper,the AVR and the manual mode FCR are analyzed,and then the mathematical model was established.Finally,this paper carried out the test of excitation system,it is includ the static test,no-load dynamic test,load dynamic test and load test of excitation system,which comprehensiuely tests the performance and parameters of excitation system of #8 units.The test results show that the excitation system can run normally for meeting thestandard requirements of the technology and the design.