基于模态级数法的功角失稳和电压失稳主导性识别

Recognition of dominant mode between power angle instability and voltage instability based on modal series method

准确区分电压稳定和功角稳定问题是评价电力系统稳定性的基础.单独分析其中某一方面的问题,不考虑两者之间的相关性,就会使分析结果不全面,从而不能准确地反映系统的真实情况.基于传统的暂态电压分析模型,利用模态级数分解法,通过分析系统平衡点附近的非线性相关因子,得到平衡点附近的非线性失稳模式,通过分析二阶解析解响应得到了主导失稳模式指标,最终确定系统主导失稳模式.通过WSC4机系统仿真结果表明,该方法能准确反映平衡点附近的稳定状态和辨别系统主导失稳模式.

It is the basis of evaluating the stability of power system to accurately distinguish between volt- age stability and power angle stability. Both of them are related with each other, so that if only one of them is analized without considering their correlativity to each other, the analysis result will be incomplete and the real condition of the system will not be reflected precisely. Based on the traditional model of tran- sient voltage analysis, using the modal series decomposition method, and analyzing the nonlinear correla- tion factors near the equilibrium point of the system, the nonlinear instability mode near the equilibrium point are obtained. Finally, the dominant instability index and mode of the system are determined by ana- lyzing the response of the two-order analytical solution. It is shown by the simulation result of WSCA ma- chine system that the proposed method can reflect precisely the stable state at the equilibrium point and discriminate the dominant instability mode of the system.