新能源汇集系统短路故障清除后的暂态过电压机理

新能源汇集系统交流短路故障后产生的非工频暂态过电压可能导致新能源机组大规模脱网甚至损毁，这已成为制约新能源汇集系统送电极限的决定性因素。基于华北地区典型新能源汇集系统构建算例系统，分析短路故障下的暂态过电压形态特征，阐明易产生暂态过电压的系统参数条件，建立数学模型进行定量研究，利用RLC电路的全响应理论解释产生暂态过电压的本质原因。分析结果表明，短路故障清除后新能源汇集系统的电路固有谐振过程是导致暂态过电压的主要原因之一。

Transient overvoltage mechanism after short circuit fault removal of renewable energy collection system

The non-power frequency transient overvoltage produced after short circuit fault of renewable energy collection system may lead to large-scale disconnection even damage of renewable energy units, which has become a decisive factor for restricting the power transmission limit of renewable energy collection system. An example system is built based on a typical renewable energy collection system in North China region, the morphological features of transient overvoltage are analyzed under short circuit faults, the system parameter conditions that are prone to transient overvoltage are clarified, a mathematical model is established for quantitative research, and the full response theory of RLC circuit is used to explain the essential cause of transient overvoltage. The analysis results show that the inherent resonance process of renewable energy collection system after short circuit fault removal is one of the main reasons of transient overvoltage.