分层土壤结构变电站接地阻抗测试信号的处理

正确测量变电站的真实接地阻抗是确保变电站安全稳定运行的基本保证 ,而测量时测试信号的正确处理是获得真实接地阻抗的关键。本文通过分析接地电阻测量信号的组成 ,提出了综合采用数字模拟方法进行信号处理 ,去除干扰的方法 ;另外通过采用等效复穿透深度法计算水平分层土壤时电压和电流测量引线间的互感 ,此方法能有效消除引线间感应电压对测量结果的影响。本文根据层状土壤的电磁场理论推导得到了水平层状土壤结构的复穿透深度。该方法在某50 0kV变电站的接地阻抗测试中进行了实际应用 ,如果不考虑测量引线间的互感 ,在本文的实例中可导致接地阻抗增加 7 3% ,影响是比较大的。本文提出的方法可为电力部门提供参考。

Measuring Signal Processing of Grounding Impedance of Substation with Layered Soil Structure

How to correctly measure the real grounding impedance of substation is the basic countermeasure to guarantee the safe and stable operation of substation,and how to correctly handle the measuring signals is the key to obtain the real grounding impedance.By analyzing the composition of the signal,digital and analog methods are used to handle the interference.The method of equivalent complex puncturing depth is proposed to calculate mutual inductance between current and voltage leads under multi-layers soil structure in this paper.This method can efficiently eliminate the influence of inducing voltage between lead wires on measuring results of grounding system.The complex puncturing depth of horizontal multi-layer soil structure is applied in grounding impedance measurement of a 500kV substation,the grounding impedance would increase 7 3% in this case if the mutual inductance between measuring leads,the influence is high.The proposed method can provide reference for power system.