计及系统连锁故障风险的电网预防控制

A preventive control strategy for power grid considering system cascading failure risk

电网连锁故障控制策略一般根据选定的运行条件和故障状态,采用确定性的安全校验方法进行预防控制,忽略了系统中存在的不确定因素,并且人为选定的故障方式难以完全反映系统动态特性。考虑初始故障、继电保护动作等不确定因素的影响,计及故障后元件运行状态变化对后续故障的影响,进行连锁故障的预防控制。建立了基于贝叶斯网络的连锁反应故障概率分析模型,对故障进行筛选和识别。根据系统故障发展过程中连锁故障搜索和分析情况,提出以连锁故障风险最小为目标的预防控制方法。针对IEEE30节点系统的故障演化路径求取预防控制措施,仿真结果表明控制策略能有效降低系统发生连锁反应故障的风险,预防连锁故障的发生。

Traditional contingency control strategy is generally based on the selected operating conditions and failure status,and adopts definite security analysis method to prevent cascading failure,which ignores the uncertain factors in the system and is hard to reflect the whole dynamic characteristic of power system because the failure status is selected artificially. Hence,it is important to consider the uncertain factors such as initial failure,relay protection actions,etc,and the effect of component operating characteristic after failure on cascading failure during preventive control process. First,Bayesian network based cascading probability analysis model is established to screen and identify failures .Furthermore,according to cascading failure search and analysis,an optimal preventive control method is built with the purpose of minimizing the contingency risk. Finally,the proposed approach is tested on the IEEE-30 bus test system. The results show that preventive control strategy can decrease the contingency risk,thus the cascading failures can be prevented effectively.