某水电厂500kV系统线路-主变中间开关重合闸见解分析

Opinion Analysis of the Intermediate Swich Reclosing of the Main Transformer for 500kV System Line of Some Hydroelectric Plant

某水电厂500kV高压输电线路采用3/2和4/3联合接线方式向外输电,主要针对特殊运行方式下,该电厂500kV线路-变压器中间开关重合闸的保护方式进行分析,虽然其具有较高的保护可靠性和供电稳定性,但该方式使用的设备多,二次接线复杂,给设备运行操作中投退自动化装置、维护继保装置带来不便。特别是对于线路-变压器中间开关保护重合闸的来说,主变故障时,不许中间开关重合于故障主变。若该中间开关单相重合闸保护退出,则在线路发生单相故障时,可能导致该中间开关三相不一致运行,对发变组和电力系统运行均会造成严重危害。对此进行分析,提出改进方法,保证发变组、电网稳定运行。

500 kV power transmission lines and the high pressure 3/2 and 4/3 joint wiring way to outside transmission, this paper is mainly for special operation mode, the plant 500 kV lines-transformer switch among the protection of reclosing mode analysis, although it has high reliability and stability of the protection of the power supply, but the way of the equipment used, secondary wiring complex, give equipment operation, maintenance automation devices has back after the device to bring inconvenience. Especially for line-transformer switch protection among the reclose it, the main transformer fault, no middle switch in main transformer faults overlap. If the middle switch single-phase reclose protection exit,it happened when a fault line in single phase, may cause the intermediate switches three-phase inconsistent running on hair become group and power system running all can cause serious harm. This paper analyzes these, put forward the improvement method, ensure hair become group, the stable operation of the grid.