220kV双母线电压切换回路异常分析及解决对策

Abnormal Analysis and Solution of 220kV Double Busbar Voltage Switching Circuit

某发电厂220kV母线倒闸操作过程中由于刀闸辅助触点不到位导致电压切换回路双位置继电器没有根据一次刀闸实际位置进行相应切换,引起双母线电压切换回路异常并列运行导致倒送电。在双母线接线方式倒闸操作过程中,如果电压切换回路发生异常并列可能会导致保护误动,甚至会烧毁电压互感器,给电网运行带来较大的风险。结合公司设备情况,对南瑞继保CZX-12R型操作箱的电压切换回路进行优化改进,防止类似案例再次发生,确保涉网设备安全可靠运行。

During the switching operation of 220kV bus in a power plant,the double position relay of voltage switching circuit did not switch according to the actual position of the primary switch because the auxiliary contact of the switch was not in place,which resulted in the abnormal parallel operation of the double bus voltage switching circuit and the reverse power transmission.In the process of switching operation with double bus connection mode,if the voltage switching circuit is abnormally paralleled,the protection may misoperate,or even burn down the voltage transformer,which will bring greater risk to the operation of power grid.Combined with the equipment situation of the company,the voltage switching circuit of Nanrui Jibao czx-12r operation box is optimized and improved to prevent the recurrence of similar cases and ensure the safe and reliable operation of network related equipment.