交流滤波器投入暂态对母线电压互感器冲击影响分析

Analysis of the Impact of AC Filter Input Transient on Bus Voltage Transformer Impulse

电容式电压互感器主要由分压电容器以及中间变压器电磁单元组成,具有体积小、成本低且抗绝缘强度大等特点。近年来不少直流换流站或变电站交流滤波器投入过程中,会在交流滤波器母线侧产生一次涌流冲击,对设备安全造成威胁,特别是母线电压互感器。通过从交流滤波器投入暂态过程、绝缘过电压保护设计、铁磁谐振、阻尼回路等角度分析原因,提出改进的方法。

Capacitive voltage transformer is mainly composed of voltage divider capacitor and intermediate transformer electromagnetic unit. It has the characteristics of small volume, low cost and high anti insulation strength. In recent years, when many DC converter stations or substation AC filters are put into operation, an inrush current will be generated on the bus side of the AC filter, posing a threat to the safety of the equipment, especially the bus voltage transformers.The reasons are analyzed from the perspectives of AC filter input transient process, insulation overvoltage protection design, ferromagnetic resonance, damping loop, etc., and solutions and improvement methods are proposed.