考虑一二次耦合多重故障的电力系统风险评估

为了综合评估恶劣天气下输电线路故障与二次系统隐性故障导致的多重故障风险，提出了考虑一二次耦合多重故障的电力系统风险评估方法。首先，分析了气象灾害导致输电线路故障的特点，总结了一二次设备耦合多重故障的特点。其次，综合考虑输电线路及保护装置的失效概率，建立了一二次耦合多重故障模型。然后，应用拉丁超立方抽样实现初始故障集的快速生成，进而评估系统失负荷、节点电压越限、支路潮流越限等风险指标。最后，采用IEEE39节点系统对所提方法进行测试。研究结果表明：考虑一二次耦合的多重故障，系统面临的风险更为严重；使用拉丁超立方抽样，可兼顾不同气象分区内线路故障概率分布差异，提高计算效率；通过多维度风险指标排序，能够有效筛选灾害天气落区内影响电网风险的关键线路和母线，为电网风险防控和薄弱环节治理提供决策依据。

Power system risk assessment considering primary and secondary coupled multiple faults

To comprehensively assess the risk of multiple faults that are due to transmission line and hidden faults in secondary systems during severe weather, a risk assessment method for power systems considering primary and secondary coupled multiple faults is proposed. First, the characteristics of transmission line faults caused by meteorological disasters are analyzed, and the characteristics of primary and secondary coupled multiple faults are summarized. Second, a primary and secondary coupled multiple fault model is established by considering the fault probability of transmission lines and protection devices. Then, a Latin hypercube sampling method is applied to quickly generate the initial fault set and evaluate the loss of load, node voltage out-of-limit, branch power flow out-of-limit, and other risk indeices. Finally, the proposed method is tested using the IEEE39-node system. The results reveal that the power system faces more serious risks when considering primary and secondary coupled multiple faults; the use of Latin hypercube sampling allows taking into account fault probability distribution differences of transmission lines within different meteorological subareas and improve computational efficiency; multidimensional risk ranking can effectively screen critical lines and buses that affect power grid risk within severe weather subareas, and provide a decision basis for power grid risk prevention and weak link management.