串联补偿的远距离输电线路潜供电弧参数特性

Secondary Arc Parameters Characteristics of Long-distance Series Compensated Transmission Lines

对于综合配置串、并联补偿的输电线路,在某些配置方案情况下,潜供电弧参数中将存在由故障相串联电容通过短路点与并联电抗器放电形成的低频分量,不利于单相重合闸的成功。基于EMTDC仿真计算和拉普拉斯变换数学分析相结合的方法,针对这一问题在远距离输电线路中表现出的特点,分别对远距离输电线路中设置和不设开关站的情况进行了研究分析。研究结果表明:在线路中不设开关站时,输电距离的增加使低频分量的振荡频率和衰减系数同时增大,导致其衰减较快。在线路中设置开关站时,即使对故障线路段故障相串补电容采取了旁路措施,某些情况下仍会有非故障线路段故障相的串补电容通过开关站内的电气联系经接地点的潜供电弧放电,产生的低频分量较严重时将影响单相重合闸的成功。在此基础上,探讨了低频分量限制措施的采用和优化潜供电弧参数的串、并联补偿配置方案等相关问题。

When transmission lines operate with series capacitors and shunt reactors, under certain circumstances, the series capacitor of fault phase can discharge through the shunt reactors and the secondary arc after the fault phase is shut off. It is a low frequency component against the single pole reclosure. With the EMTDC simulation and Laplace transformation analysis, this paper analyzes the feature of this low frequency component in a long-distance series compensated transmission line with and without switching station. With the increase of transmission distance, the decay factor and oscillation frequency increases at the same time, and the stored charge will be discharged faster. When the transmission line is with switching station, although the series capacitor of fault phase in fault line section is bypassed, the series capacitor of fault phase in healthy line section still discharges through the secondary arc under certain conditions. This low frequency component sometimes is serious and harmful to single pole reclosure. Based on these results, adoption of limiting the low frequency component and optimizing the scheme of series and shunt compensations are discussed.