基于精确隐性故障模型的输电系统连锁故障风险评估

Risk Assessment of Transmission System Cascading Failure Based on Accurate Hidden Failure Model

针对继电保护隐性故障进行研究,改进了现有的隐性故障模型,并在此基础上评估了保护隐性故障造成连锁故障的运行风险。首先根据不同隐性故障造成保护不正确动作概率的不同,将隐性故障详细分类,建立了隐性故障概率模型;其次应用置信规则库,建立考虑环境和系统潮流影响的保护系统马尔可夫模型,将隐性故障概率模型和马尔可夫模型结合,建立精确隐性故障模型。再次,根据隐性故障造成连锁故障的传播机理,建立连锁故障模型,并从概率、网络结构、能量损失3个角度建立相关的严重度指标。最后,将模型应用于IEEE-118系统,通过对比传统隐性故障模型和文中所提精确隐性故障模型所得风险评估结果,验证了所提精确隐性故障模型更加贴合实际,其风险评估结果更加真实可靠。

In this paper, hidden failure of protective relay is investigated and existing hidden failure model was improved. Based on the model, cascading failure risk caused by hidden failure was assessed. Firstly, according to different probabilities of misoperation caused by different hidden failures, hidden failures were categorized in detail. Then hidden failure probability model was established. Secondly, Markov protection model changing with environment and load flow was presented. Markov protection model was based on confidence rule base. Then accurate hidden failure model was established by combining probability model with Markov model. Thirdly, a cascading model with three assessment indexes including probability, structure and energy loss was developed. Finally, based on IEEE-118 system, comparison between traditional hidden failure model and the proposed hidden failure model showed that the proposed model is more realistic and its assessment result is more reliable.