| With the development of the remote transmission system and the foundation of grid system as well as the usage of high capacity generator set in the system, it becomes an important problem that how to keep the operation of power system stable and reliable. The synchronous generator's excitation system plays an import role in advancing power system's stability and reliability. Enhancing the performance of excitation devices has been acknowledged as one of the most efficient and the most economic method to improve generators'stabilities.The excitation controller and the excitation manner are regarded as two aspects of excitation system's development. This paper represents the self-shunt excitation system's merit and flaw and discusses some problems about excitation transformer of main circuit, silicon controlled rectifier and the parameters'selection of some extra equipments. For excitation controller the generation reasons of negative damping and the improvement programs are studied by analyzing mathematic model of self-shunt excitation in detail. Then the excitation manners which take automatic voltage regulator (AVR) as main control and power system stabilizer (PSS) as auxiliary control are the focus of the paper. The characteristics of PSS with different input modes are studied and their merit and flaw are analyzed, which provide the gist for selection of stabilizers.In the end of this paper a model of single-machine infinite bus system with excitation controller is constructed and simulated by Sim-PowerSysems toolbox of Matlab, which certifies the results of theory analysis for excitation system. According to the results of excitation simulation the performance of PID excitation control system is analyzed. And the influences of the excitation control with different stabilizers on control target are discussed, as well as the dynamic curves of excitation system with different stabilizers are cross compared. Then the references for excitation system's design and selection are derived. |
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