谐振接地系统电容电流检测的改进调谐法

The Improved Tuning Method for the Detection of Capacitance Current in Resonant Grounding System

谐振接地系统中的消弧线圈调谐控制依赖于接地电容电流检测,以安徽芜湖某变电站为背景,研究了接地电容电流检测的方法。首先介绍了调谐法基本原理以及两种主要调谐方法;然后以提高接地电容电流检测精度为目的,考虑PT精度及测量等环节在中性点电压较低时的影响,提出了利用切掉阻尼电阻来放大中性点电压的改进调谐法;采用本文方法分析了装有阻尼电阻的串联谐振回路,给出了具体实施步骤;最后基于实际系统进行了MATLAB仿真,结果表明文中所提出接地电容电流检测的改进调谐法合理有效。

The tuning control of the arc-suppression coil depends on the detection of grounding capacitance current in resonant grounding system.Taking a substation in Wuhu as example,the detection method of grounding capacitance current is studied in this paper.The principle and two main methods of tuning are introduced firstly.By considering the influence of accuracy of PT and measurement part when the neutral point voltage is low,an improved tuning method by cutting damping resistance is presented to improve detection accuracy of capacitance current.The feasibility of this method is verified by analysis of equivalent circuit of series resonance with damping resistance theoretically,the detail step is also presented.Finally this method is simulated by MATLAB,and results show that the proposed method is rational and effective.