大电网连锁故障风险评估方法研究

发布时间：2018-06-12 10:19

本文选题：电力系统 + 连锁故障　；参考：《哈尔滨工业大学》2014年硕士论文

【摘要】：随着经济的不断发展，，用电量的需求急剧增大，大电网应运而生。电网规模的扩大，虽然提高了供电水平，但也给电网的安全可靠运行带来新的挑战。近年来国外发生了多起大停电事故，使得连锁故障及其风险评估成为了研究热点。本文首先建立基于实时运行状态的连锁故障停运概率模型。模型包含两个部分：考虑不同停运因素的线路、发电机、负荷停运模型；考虑保护动作逻辑的隐性故障模型。基于脆弱度和灵敏度对初始故障进行重要度排序，适当地筛选初始故障。考虑继电保护隐性故障，按一定的终止条件进行模式搜索，模拟电力系统连锁故障。最终找到连锁故障路径，并求出不同终止条件下发生连锁故障的概率。其次，在连锁故障路径的基础上，考虑故障的严重度，从静态安全的角度，基于效用熵原理，定义运行风险指标，建立连锁故障风险评估模型，并用层次分析法和主成分分析法对各项风险指标进行综合评估。在完成连锁故障风险指标综合评估的基础上，将连锁故障综合风险指标与连锁故障概率指标、发生初始故障的概率作比较，结果显示：综合风险评价指标与概率评价指标的趋势基本一致，可以定量地比较出哪些线路发生连锁故障后给系统带来的后果比较严重；而发生初始故障概率大的线路未必风险值大，两者之间并无必然联系。最后，采用聚类分析方法对概率指标、脆弱度指标和风险指标进行分级。基于模糊推理方法建立风险指标的隶属度函数，获得综合风险指标的分级结果。综合考虑概率指标、脆弱度指标和综合风险指标，实现对连锁故障的分级预警。这一方法全面考察了概率、脆弱度以及风险对系统的影响，对于低概率、高风险的故障也能正确、有效进行预警。以10机39节点系统进行计算分析，结果显示：该方法可有效地对系统进行风险评估及分级预警，表明了该方法的有效性。
[Abstract]:With the continuous development of economy, the demand for electricity consumption increases sharply, and large power grid emerges as the times require. The expansion of power grid has raised the level of power supply, but also brought new challenges to the safe and reliable operation of power grid. In recent years, many power outages have occurred in foreign countries, which makes cascading faults and their risk assessment a hot topic. Firstly, the probability model of cascading failure outage based on real-time operation state is established in this paper. The model consists of two parts: line with different outage factors generator load outage model and hidden fault model considering protection logic. The importance of initial faults is sorted based on vulnerability and sensitivity, and the initial faults are properly selected. Considering the hidden fault of relay protection, the mode search is carried out according to certain termination conditions, and the cascading fault of power system is simulated. Finally, the cascading fault path is found, and the probability of cascading fault under different termination conditions is obtained. Secondly, considering the severity of the fault, based on the utility entropy principle from the point of view of static safety, The operational risk index is defined, the risk assessment model of cascading fault is established, and the comprehensive evaluation of each risk index is carried out by the analytic hierarchy process (AHP) and the principal component analysis (PCA). On the basis of comprehensive evaluation of risk index of cascading fault, the probability of initial failure is compared with that of comprehensive risk index of cascading fault and probability index of cascading fault. The results show that the trend of the comprehensive risk evaluation index and the probability evaluation index is basically the same, and it can be quantitatively compared which lines have serious consequences for the system after the cascading faults occur; However, the line with high probability of initial failure is not necessarily related to the risk. Finally, the probability index, vulnerability index and risk index are classified by cluster analysis method. The membership function of risk index is established based on fuzzy reasoning method, and the classification result of comprehensive risk index is obtained. Considering probability index, vulnerability index and comprehensive risk index, hierarchical early warning of cascading faults can be realized. The influence of probability, vulnerability and risk on the system is comprehensively investigated in this method. For the low probability and high risk fault, it can also be correctly and effectively forewarned. The results show that the method is effective in risk assessment and hierarchical early warning of the system, and the effectiveness of the method is demonstrated.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM711

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