计及水轮机调速系统作用的电力系统强迫振荡机理研究

Research on Mechanism of Force Oscillation Considering the Effect of Turbine′s Governor System in Power System

从理论上分析了不同阻尼状况、不同扰动下,电力系统强迫功率振荡情况.详细分析了外界扰动源频率与发电机组固有振荡频率相同或相近时,对系统功率振荡幅值的放大作用;研究了发电机组调速系统的固有振荡频率与输入扰动具有相同或相近频率时,调速系统发生共振的机理.当调速系统发生共振时,导水叶在调速系统的调节作用下发生大幅度振荡,输出机械功率也随之振荡.如果输出机械功率振荡频率与电力系统固有振荡频率相同,就会使系统发生持续性的强迫功率振荡.建立了MATLAB仿真模型,验证了理论分析的正确性.

Under the conditions of different disturbances and damping,the characteristics of forced power oscillation in power system are analyzed in this paper.A detailed analysis is done to the amplification on amplitude of the system power oscillation in the case of external disturbance source frequency equal or similar to the natural oscillation frequency of generator.The resonance mechanical theory is studied when the natural frequency of generator governor system is equal or similar to external disturbance source frequency.When resonance occurs in the generator governor system,the flow guide vane will oscillate severely under the effect of governor system.If the output mechanical power frequency is equal to the natural frequency of power system,continual oscillation occurs in the system.A single-machine infinite-bus simulation model is established based on MATLAB,which verifies the correctness of the analysis.