全过程电压稳定故障筛选和排序方法及辅助决策

Full-Dynamic Voltage Stability Contingency Screening and Ranking Method and Control Strategy

提出了全过程（机电暂态和中长期）电压稳定故障筛选和排序方法。中长期电压失稳的可能性不可忽视,但是中长期分析难以应对大量故障。为了克服这一困难,通过静态、暂态和中长期三个分析阶段进行严重故障的筛选和排序。首先利用静态和暂态分析手段从预想故障集中筛选出可能导致中长期电压失稳的故障,再利用中长期分析手段针对这一部分故障进行校核。基于实际电网对所提方法进行了测试,静态分析阶段有效筛选出了功率裕度较低的故障;暂态分析阶段筛选出了少量导致过励和电压稳定裕度较低的故障;中长期分析阶段从中筛选出了中长期电压失稳故障;针对电压失稳故障,在关键节点制定了辅助决策,实施后能够使系统保持电压稳定。

A systemic approach of full-dynamic（electro-mechanical transient and mid-long term） voltage stability contingency screening and ranking was proposed. Mid-long term voltage instability possibility was non-negligible, but it was difficult for mid-long term analysis to deal with large number of contingencies. To address this problem, critical contingencies were captured through three stages of analysis, i.e. static, transient, and mid-long term. Firstly, static and transient analysis methods were used to shortlist a number of probably critical contingencies form a large list of credible contingencies. Mid-long term analysis method was then used to identify contingencies causing mid-long term voltage instability from the list. Testing on practical power systems showed that static analysis stage screened out low MVA margin contingencies, transient analysis stage shortlisted a number of contingencies of over excitation and low voltage stability margin, and mid-long term analysis stage finally screened out contingencies causing mid-long term instability from them. Under contingencies caused by voltage instability, control strategies were made on critical nodes, and they were able to mitigate voltage instability.