基于等效电路法的负阻尼能量机理及振荡源定位方法探讨

Discussion on Energy Mechanism of Negative Damping and Oscillation Source Locating Method Based on Equivalent Circuit Method

为解释自由振荡中产生振荡源的机理,在能量法基础之上提出了等效电路法。对电力系统各元件分别建立了其等效电路并组合得到系统的等效电路。根据电路理论,将积分形式的振荡源定位判据转化为相量判据。对于励磁系统,提出了3种振荡源定位判据。将这3种判据转化为相量形式并组合,分析了励磁系统产生振荡源的机理。算例仿真证明了该分析方法的正确性和有效性。该方法可用于在线定位励磁系统振荡源,并分析由于励磁参数设定不当而形成振荡源的机理。

In order to explain the mechanism of forming oscillation source in free oscillation, an equivalent circuit method based on the energy method is proposed. The equivalent circuits of various parts of the power system are developed, and the equivalent circuit of the system is obtained by combining them together. According to the circuit theory, an oscillation source locating criterion calculated with integral is converted into a variety of criteria represented by phasors. Three criteria are proposed for locating the oscillation source of the excitation system. By converting the three criteria into criteria represented by phasors and combining them together, the mechanism of forming oscillation source in the excitation system is analyzed. The correctness and effectiveness of the methods are verified by simulation. The methods proposed can be used to locate the oscillation source in the excitation system online and analyze the mechanism of oscillation source formed by inappropriate excitation parameter setting.