选相抑制1000kV线路合闸过电压的仿真研究

Simulation Research on Limit of Closing Overvoltages by Phase-controlled Technology in 1000kV Transmission Lines

为分析选相技术抑制1000k V空载输电线路合闸过电压的效果,首先研究了断路器的合闸预击穿特性和目标合闸相位,然后利用PSCAD/EMTDC软件的自定义模块建立了能考虑合闸预击穿特性及选相控制策略的合闸模型,最后对应用选相技术的1000k V空载线路统计合闸过电压进行了仿真分析,并与随机合闸、加装合闸电阻和金属氧化物避雷器下的统计过电压倍数进行了对比。结果表明:采用选相合闸技术配合避雷器的过电压抑制方式能将计划合闸过电压限制在1.6p.u.以下,将单相重合闸过电压限制在1.7p.u.以下,满足相关标准的要求,同时能够降低避雷器的吸收能量,并有效改善合闸的过渡过程。

In order to analyze the limit effect of the phase-controlled technology, on closing overvoltages of 1000kV nonloaded transmission lines, the closing pre-strike characteristics and target closing phases of circuit breakers were studied firstly. And then, using the custom module in the PSCAD/EMTDC software, a closing model considering both closing pre-strike characteristics and phase-controlled strategy was developed. Finally, the statistics closing overvoltages of 1000kV nonloaded transmission lines were simulated, the multiple of statistics overvoltages using the phase-controlled technology was compared with that of random closing, installing closing resistor and metal oxide arrester. The results show that the phase-controlled technology in coordination with metal oxide arrester can limit the planned closing and single-phase reclosure overvoltages to be below 1.6p.u. and 1.7p.u., respectively, which meet the requirements of relevant standards, also can reduce the absorbed energy by arresters and improve the closing transient process.