计及SSSC的高渗透率新能源电网静态电压稳定特征研究

Static voltage stability characteristics of high permeability new energy grid considering SSSC

随着大规模风电、光伏等新能源接入电网,高渗透率新能源逐渐影响到电力系统的安全稳定运行。同时受新能源接入电网的网架特性约束以及新能源装备自身安全限制,新能源并网后的静态电压问题更加突出。探讨分析了计及静态同步串联补偿器(SSSC)的高渗透率新能源电网系统静态电压稳定特征,从系统静态电压特征方面评估SSSC发挥的潮流控制效能。首先分析了SSSC的等效电路及工作原理,并基于SSSC的等效功率注入模型得到潮流计算方程;其次,基于潮流计算方程提出能够反映系统静态电压稳定特征的效能评估指标,并计算分析接入不同容量新能源对静态电压稳定特征的影响,以及SSSC对新能源并入电网后薄弱节点静态电压稳定特征的影响;最后通过仿真验证,安装SSSC后能够改善新能源电网薄弱节点的电压稳定问题,提升电力系统运行时的安全稳定性。所提方法具有快速简洁的特点,并且具有一定的工程应用价值。

As large-scale wind power, photovoltaic and other new energy sources are connected to the power grid, new energy with high permeability gradually affects the safe and stable operation of the power system. Meanwhile, the static voltage problem becomes more prominent after the new energy is connected to the power grid due to the constraints of the grid characteristics of new energy sources and the security limitations of new energy equipment. The static voltage stability characteristics of high permeability new energy power grid system with static synchronous series compensator(SSSC)are discussed, and the power flow control efficiency of SSSC from the aspect of system static voltage characteristics is evaluated. Firstly, the equivalent circuit and working principle of SSSC are analyzed, and the power flow calculation equation is obtained based on the equivalent power injection model of SSSC.Secondly, based on the power flow calculation equation, a performance evaluation index is proposed to reflect the static voltage stability characteristics of the system, and the influence of different capacity of new energy on the static voltage stability characteristics, and the influence of SSSC on the static voltage stability characteristics of weak nodes after the integration of new energy into the power grid is calculated and analyzed. Finally, through simulation, it can be verified that the installation of SSSC can improve the voltage stability of weak nodes in the new energy grid and improve the safety and stability of the power system during operation. The method presented is quick and simple, and has certain engineering application value.