多馈入直流输电系统换相失败风险评估简化指标

Research on Simplified Indicators of Commutation Failure Risk Assessment for Multi-infeed HVDC Transmission Systems

换相失败是直流输电系统最常见的故障,受端系统交流故障是其最主要的诱因之一。对于大规模多馈入交直流系统,如何准确并快速地评估受端系统交流故障导致多回直流系统同时换相失败的风险,对于保障我国电网安全稳定运行、防止大停电事故发生具有重要意义。考虑电力系统实际运行情况,基于临界交直流系统电压耦合作用因子(critical AC-DC voltage coupling factor,CADVCF),推导出简化临界交直流系统电压耦合作用因子(simplified critical AC-DC voltage coupling factor,SCADVCF)的3种计算公式,解决了受端交流系统规模过大导致的计算繁杂的问题。针对直流系统额定功率运行和非额定功率运行的场景,分别给出了不同的换相失败风险评估方法。仿真结果证明了所提简化指标和评估方法的准确性和有效性。

Commutation failure is the most common fault in HVDC systems,and the receiving-end AC system fault is one of its main causes.For large-scale multi-infeed AC/DC systems,how to accurately and quickly judge whether the AC faults of the receiving system will cause simultaneous commutation failure in the multi-infeed HVDC system(MIDC),which is of great significance to ensure the safe and stable operation of China’s power grid and preventing the occurrence of blackouts in China.Considering the actual operating conditions of the power system,based on the critical ac-dc voltage coupling factor(CADVCF),three calculation formulas of the simplified critical AC-DC voltage coupling factor(SCADVCF)were derived,and the complicated calculation problem caused by the large scale of the receiving-end AC system was solved.For the rated power operation and non-rated power operation of HVDC systems,different assessment methods for evaluating commutation failure risk were given respectively.Finally,the simulation results proved the accuracy and effectiveness of the proposed simplified indicators and evaluation methods.