基于点渗流和熵权法的连锁故障路径风险评估

Risk Assessment on Cascading Failure Path Based on Site Percolation and Entropy Weight Method

为了搜索电力系统连锁故障发展路径,提出了支路故障预测模型和连锁故障路径风险评估模型。首先在点渗流理论的基础上建立了支路潮流转移渗流概率模型,结合支路抗冲击因子得到支路故障渗流概率,得到故障支路候选集,考虑保护的隐性故障对故障支路候选集修正;其次,建立了评估支路故障对系统影响程度的功率、电压、失负荷3个后果分项指标,采用熵权法计算3个分项指标的客观权重,建立了连锁故障路径的风险评估模型。IEEE39节点系统的仿真结果表明,所提模型能够准确找到各级的故障支路候选集、风险最大的连锁故障路径,验证了模型的有效性。

In order to search for the cascading failure path of power system,a forecasting model of branch fault and arisk assessment model of cascading failure path are built in this paper. First,a power flow transfer percolation probabili-ty model of branch is established based on site percolation theory with the combination of branch impact-resistant abili-ty,thus the branch fault percolation probability is obtained and the fault branch candidate set is formed. With the con-sideration of the hidden fault of protection devices,the fault branch candidate set is modified. Second,three conse-quence sub-indexes are set up with respect to power,voltage and load,which can evaluate the impact of branch fault onthe system. The objective weights of these sub-indexes are calculated according to the entropy weight method,and arisk assessment model of cascading failure path is established. Finally,the simulation results of an IEEE 39-node sys-tem show that the proposed model can accurately find the fault branch candidate set at all levels and the cascading fail-ure path with the highest risk,which verifies its effectiveness.