特高压远距离高补偿度串补线路故障清除操作过电压特性及对策

Fault Clearing Switching Overvoltage Characteristics and Countermeasures on UHV Long Distance Line With High Compensation Degree Series Capacitors

在远距离特高压线路上加装高补偿度串补是实现更远距离、更大容量输电的合理选择,在我国特高压电网发展及全球能源互联网战略中具有广阔的应用前景。特高压高补偿度串补线路发生故障清除过程中,在健全相和相邻线路上产生的操作过电压与无串补或常规串补线路相比有升高趋势,且在现有避雷器及线路保护联动旁路串补措施条件下可能超过现有标准限值,有必要开展过电压特性及抑制措施研究。文章采取理论分析和数字仿真手段,研究了高补偿度串补对特高压线路故障清除操作过电压的影响特性,并基于闪络率评估,分析了快速联动旁路串补、加装低残压避雷器及"联动+低残压避雷器"组合等多种措施对故障清除过电压的抑制效果,并提出了综合对策。研究成果可为特高压远距离高补偿度串补线路的工程设计、设备选型提供技术依据,为实现跨区或跨国输电提供技术支撑。

Installation of high degree series compensation（SC） in long distance UHV line is a reasonable choice to realize farther distance and larger capacity transmission. It has broad application prospects in development of China＇s UHV power grid and global energy interconnection strategy. During line fault and circuit breaker tripping of UHV lines with high degree compensation, overvoltage on healthy phases and adjacent lines is higher than that on lines without SC or with conventional SC, maybe exceeding standard-specified limit in condition of existing MOA and line protection linkage bypass SC measures. It is necessary to make a thorough analysis on voltage characteristics and to investigate new effective suppression measures. Through theoretical analysis and numerical simulation, this paper studies characteristics of fault clearing overvoltage of UHV transmission line with high degree compensation. Based on flashover rate evaluation, measures, such as linkage fast bypass SC, low residual voltage of MOA and combination of linkage and low residual voltage MOA and so on, are researched for fault clearing overvoltage inhibitory effect,and comprehensive countermeasure for fault clearing overvoltage is put forward. Research results can provide technical basis for engineering design and equipment selection for UHV long distance lines with high degree compensation, and also can support to achieve trans-regional and cross-border power transmission.