母联电流相位比较式母差保护放电回路分析

Analysis on Inhibiting Auto Reclose of the Bus Bar Differential Protection

母联电流相位比较式母差保护在110kV及以上双母线接线的厂站中广泛应用,为防止非预期的重合闸,220kV母差保护的出口接分相操作箱的直跳端子,而110kV母差靠放电继电器给线路重合闸放电。通过对母联电流相位比较式母差保护放电回路的分析,指出了部分设计中该回路不能可靠起到放电作用,应改进放电回路或更换放电继电器。

The bus bar differential protection based on the current phase of bus liaison CB is widely used in double bus substation over 110 kV. In order to prevent the unprospective auto reclose, the trip output of 220 kV bus protection connects to “R” of control terminal, but for 110 kV bus protection,there is a relay to inhibit auto reclose. In some design this circuit is not reliable in inhibiting auto reclose, so, the inhibiting auto reclose relay must be replaced or its circuit improved.