摘要
500kV输电线路安装串联电抗器后,断路器开断短路电流时产生的暂态恢复电压(TRV)较高,可能会导致断路器重燃而无法正常开断。文中以江苏500kV电网为对象,建立了断路器TRV仿真计算模型,研究石牌-常熟南线安装串抗后,出现单相接地故障时断路器的TRV,分析断路器断口两端的TRV是否满足超出了其绝缘水平,提出了相应的抑制措施,并通过仿真计算验证了措施的有效性。计算结果表明,石牌侧安装串抗后,其断路器TRV不符合标准要求,可在串抗两端并联35 n F以上的电容器有效抑制TRV的上升率。文中成果可为串抗及TRV防护措施在工程中的实际应用提供理论参考。
For the 500 kV transmission lines with series reactors, high transient recovery voltages（TRVs） may be caused between the contacts of the breakers when they are dropping out short circuit currents. A serious TRV may result in a restrike,which makes cutting short circuit current off different. In his paper, a TRV simulation model for the 500 kV grid in Jiangsu province is constructed. There are two series reactors installed on the line between Shipai substation and Changshu South substation in the model. The TRVs are calculated when a single-phase earth fault occurred at different positions in the line. A protection scheme is proposed and verified by calculations. The results show that the TRVs are too high to meet the requirements in the standard when there are series reactors on the line without protections. The TRVs can be suppressed effectively by installing a parallel capacitor with reactor. The capacitance should be greater than 35 n F. This work provides a reference for the practical application of series reactor and protections against TRV in projects.
出处
《江苏电机工程》
2014年第6期45-47,共3页
Jiangsu Electrical Engineering
