Research On The Stability For The Synchronous Machine Excitation System In Pumped-Storage Power Station

Pumped-Storage power station is one of the effective means to load peak removal and load valley filling, and improving the power system economy and reliability. The synchronous machines play an important role in energy conversion in the working process of the power plant. Excellent excitation control system can not only ensure the reliable operation of generators, but also enhance the effective performance of the system.Based on a maintenance project of an excitation control system of an internal Pumped-Storage power station, this paper has specifically made researches on the static excitation system’s excitation control of the synchronous generator.First of all, this paper introduces the excitation controller operating mode, analyzes the low-frequency oscillation mechanism in detail when the excitation system is running in the grid and explains the working principle of PSS (Power System Stabilizer) and tasks of the excitation system.Secondly, in order to analyze the stability of the excitation control system, this article establishes the static excitation systems’ double-loop mathematical model under the no-load state of synchronous generator, resulting from the models of the synchronous machine and the excitation system. Additionally, this topic tries using fuzzy self-tuning PID control algorithm as the generator terminal voltage control method.Finally, this paper makes simulation research on the excitation control system respectively based on the conventional PID control algorithm and the fuzzy self-tuning PID control algorithm using MATLAB software. Through the generator terminal voltage simulation curves using different control algorithms, results show that the fuzzy self-tuning control algorithm does not depend on the object’s precise mathematical model, and it has strong robustness.