单电源线路保护问题分析及对策

Problems and countermeasure of radial supply line protection

单电源线路在220kV系统中广泛存在,这些线路保护在运行中有些明显不同于双电源线路的特点。为发现、解决存在的问题,河北省调从电网运行的实际需求出发,组织进行了针对国内主流保护装置的动模试验,分析了运行对策。从试验结果看,纵联保护的动作、保护选相等存在一定问题,线路运行方式、变压器中性点接地方式、保护弱馈控制字的整定、线路重合闸方式等对不同保护的运行性能有不同的影响;从保护运行的角度看,应立足于现状,采取简洁、可靠的处理措施。正常单电源单回线运行,可不依赖纵联保护;临时单电源线路,末端变压器中性点均接地,末端保护置弱馈。河北电网采取的运行对策已付诸实践,效果良好。

The single source radial supply lines are general arranged in 220kV power system. There are some special problems in operation other than the double source supply lines. With a view of actual demand in grid, the dynamic examination to internal main protection equipment is organized by Hebei Electric Power Dispatching Centre, for discovering and solving of problems. At the same time, the countermeasure is took into account. Think of examination result, there are some problems in operation of pilot protection and select polarity, which have a different effect on the different protection, running mode of the lines, grounded mode of the terminal transformer, setting of feedback control code, reclosing mode of the lines,etc. The dispositional measure must be succinct and reliable from the point of view of operation. The pilot protection may be unused for the natural single source radial supply lines. For the interim lines, the terminal transformer should be grounded, and the terminal feedback should be used. The Hebei province is succinct and effective.