TY系列小电流接地选线装置注入电流分析

Analysis of Injection Current of TY Series Low Current Grounding Line Selection Device

介绍了TY系列小电流接地选线装置的原理,对电压互感器短路阻抗进行了计算,在此基础上,分析了不同电压互感器接线方式下10 kV和6 kV系统单相接地时TY系列小电流接地选线装置向电压互感器二次侧注入的电流,对注入电流与实际注入电流进行了对比。同时分析了注入电流限值问题和增大注入电流的影响。通过分析得出结论,发生6 kV~10 kV系统单相接地时,TY系列小电流接地选线装置的注入电流不宜高于3 A,这样基本不影响电压互感器的正常运行。

The principles of the TY series low current grounding line selection device were introduced,and the short-circuit impedance of the voltage transformer was calculated.On this basis,the current injected into the secondary side of the voltage transformer by the TY series low current grounding line selection device when the 10 kV system is single-phase grounded under different voltage transformer wiring modes was analyzed as well as 6 kW system,and the injection current and the actual injection current were compared.At the same time,the injection current limit and the influence of increasing injection current were analyzed.It is concluded through analysis that when single-phase grounding occurs in the 6 kV~10 kV system,the injection current of the TY series low current grounding line selection device should not be higher than 3 A,so that it will not affect the normal operation of the voltage transformer.