电网大扰动动态稳定影响因素分析

Analysis of Influencing Factors of Power Grid Dynamic Stability under Large Disturbances

电力系统受到大扰动后,由于受到动态过程中非线性因素和事故后潮流重新分配两方面因素影响,电网自身阻尼特性会发生改变。首先研究事故后方式和非线性因素对电网受到大扰动后动态稳定性的影响,然后通过对非线性因素与事故后方式共同作用下的大扰动动态稳定进行分析,得出大扰动下若自动调节控制装置的非线性环节对电网阻尼特性影响较小,则电网大扰动动态稳定性主要由事故后方式下电网自身阻尼特性决定的结论。最后,利用某电网实际运行方式的仿真分析对结论进行了验证。

When the power system is subjected to large disturbances,the damping characteristics of the power grid itself change due to two factors： the nonlinear factors in the dynamic process and the reallocation of power flow after the accident. In this paper,first,the impact of the accident operation mode and nonlinear factors on large disturbances dynamic stability of the power grid is studied. Second,the large disturbance dynamic stability under the joint action of the accident operation mode and nonlinear factors is analyzed,and a conclusion is obtained that if the nonlinear part of the control and automatically adjusting devices have little effect on the damping characteristics of a power grid,the large disturbance dynamic stability of the power grid is mainly determined by the damping characteristics of the grid itself under the accident operation mode. Finally,the results are verified by simulations of the actual operation mode of a power grid.