为解决大规模风电接入电网后可能引起的紧急低频问题,提出一种抽水蓄能机组的低频切泵策略。传统的切泵策略没有考虑大规模风电接入后的影响,而该策略推导了风电接入后电网动态频率轨迹的计算方法。基于最优频率轨迹的方法建立目标函数并给出约束条件,采用外点罚函数法优化求解。利用PSASP软件对某个省电网进行仿真,结果显示:大规模风电接入后渗透率能对电网频率动态轨迹产生影响进而会影响到切泵的方案,但在不同渗透率下优化方案的各项性能指标均好于未经优化的。这表明,不同渗透率的风电接入电网后,经过所提优化的方案均能获得良好的控制效果,这为首次利用抽水蓄能解决大规模风电带来的紧急低频问题提供了理论的依据和现实的手段。
Traditional strategy does not consider the influence brought by wind power. To solve the low frequency problems of power system caused by large scale wind powers, this paper proposed a novel under frequency pump shedding strategy. The calculation methods of frequency dynamic curve were inferred, with large scale wind power integration into the system. The objective function was established and constraint conditions were given and the function was solved by external point function method. At last simulation results with PSASP packages verified the effect of wind power penetration on frequency dynamic process and it also confirmed that the optimal strategy of under frequency pump shedding have a better effect on restoration of the grid frequency. It gives a theory evidence and practical means of using pumped storage power station to solve the low frequency problems caused by large scale of wind power.