考虑线路停运概率的电力系统连锁故障阻断控制

Blocking Control of Power System Cascading Failures Considering Line Outages Probability

随机故障造成系统潮流转移,并进一步导致线路过载停运是引发连锁故障的一个重要因素,对此,提出一种考虑线路停运概率的连锁故障阻断控制方法。首先,基于输电线路可靠性模型搜索过载主导型连锁故障路径,并根据风险指标筛选高风险路径。在此基础上,针对高风险的连锁故障路径,将阻断控制表述成一个基于风险指标的多阶段最优潮流问题。以调整发电机出力、切负荷为调控手段,将线路运行可靠性模型用Sigmoid函数近似表示并作为约束,建立连锁故障阻断控制模型,然后采用内点法求解该问题。算例分析表明,由该连锁故障阻断控制方法得到的控制方案能够考虑线路故障概率的影响,在阻断连锁故障发展的同时,有效协调安全性和经济性的需求。

Power flow transfer and transmission line overload caused by random contingencies is an important factor leading to cascading failures.A blocking control model of power system cascading failures is proposed considering the probability of transmission line outages.Based on operational reliability model,the spread path of overload-dominated cascading failure is searched,and high risk paths are selected according to risk indices.On this basis,for a specific cascading failure path,the blocking control is described as a multi-stage optimal power flow problem based on risk indices.Taking the means of adjusting the output of generators and shedding load,a blocking control model is proposed.In this control model,the operational reliability model is approximated with Sigmoid function and considered as a constraint.At last,interior point method is used to solve the model.Case study shows that the control scheme generated from the blocking control method could consider the influence of failure probability and effectively coordinate the demands of security and economy while blocking development of cascading failures.