恶劣天气下的复杂电网连锁故障在线预警

尽管网架结构日益坚强,但部分区域电网主通道线路走廊气候条件复杂,恶劣天气导致元件发生"故障聚集"现象使电网发生连锁故障的概率大大提高。为此通过分析恶劣天气下电网连锁故障的产生机理,结合小世界理论提出了恶劣天气下复杂电网连锁故障在线预警模型。利用电网具有自组织临界性的特点提出电网临界线路的判断约束标准,通过考察系统局部元件集合性质变化的方式来预判系统整体是否存在进入自临界状态的趋势。分析认为长程连接线路是传播连锁故障的主要路径,并提出以线路介数来定义长程连接线路。预警模型对临界线路集中的长程连接线路进行预警,可为调度员预防连锁故障的发生提供依据。对中国某区域电网的仿真分析验证了理论方法的正确性和预警模型的有效性。

Online Early Warning Model for Cascading Failure in Complex Power Grid Under Severe Weather

Even though the main sturctures of power grids are strengthened increasingly,due to complex weather conditions of the partial corridors for main transmission lines of regional power networks the severe weather leads to the phenomena of ’failure aggregation’ that makes the probability of occurring cascading failure in power grid greatly increased.By means of analyzing the meachnism leading to cascading failures under severe weather and combining with the small world theory,an online early warning model for cascading failures in complex power grid under severe weather was proposed.Through the analogy of sandpile model with powr system a concept of ’critical line’ was put forward,and utilizing self-organized criticality of power system the constraint to judge whether a transmission line was in a critical state was given,and by means of examining the change of partial components cluster status of power system it could be prejudged whether there was the trend that the whole system might enter into self-organized critical status.Analysis results showed that the long range connectivity line was the main path along which the cascading failure was propagaeted,and it was proposed that the long range connective line could be defined by line betweenness.Both the correctness of the proposed method and the effectiveness of the proposed early warning model were verified by simulation results of a certain regional power grid in China.The proposed early warning model can search out the long range connectivity line in critical line set and deliver early warning to the dispatcher to prevent the occurrence of cascading failure.