既定PSS在不同运行状态下的适应性分析*

分析了不同运行状态下既定PSS的适应性。首先阐述了Prony算法的基本思想,并通过案例验证了Prony方法在工程PSS分析中精度是可行的;然后通过PSD-BPA仿真计算分别分析了机组负荷系数、电网负荷、电网结构变化时机组的振荡特性变化规律和既定PSS的适应性,并给出了PSS参数整定的建议参考流程。分析表明,机组负荷系数和电网负荷增大均会使发电机主导振荡频率降低,但电网结构改变时,其主导振荡频率有可能升高也有可能降低,不具备明显规律;当机组负荷系数变大时,既定PSS适应性先变差再变好,而当电网负荷增大时,结论相反。论文成果对于PSS参数的整定改进有参考意义。

Adaptation Analysis on Fixed PSS under Different Performing Conditions

This paper investigates the adaptation of PSS under different running conditions.The basic principles of Prony are firstly studied, and the accuracy of this method for the engineering calculation is also confirmed by an exam-ple.Then, based on the PSD-BPA simulation computing, the vibration characteristics of the generator set, and the adaptation of PSS with the variations of the generator load factor, the grid load and the grid structure are respectively analyzed.The corresponding suggested flow chart of the PSS parameter setting is proposed as well.It is shown that, as the generator load factor or the grid load is increased, the vibration frequency of generator will be decreased.Howev-er , there are no evident rules for the frequency change when the grid structure is changed.As the generator load factor rises, the adaptation characteristic will be firstly debased and then optimized, while the increment of the grid load will result in an opposite result.The achievements obtained in this paper can be used as a reference for the PSS parameter setting improvement.