基于组合波工程化测量消除引线互感的接地阻抗测量方法

Ground Impedance Measurement Method based on Combined Wave Field Measurement to Eliminate Mutual Inductance

摘要:

摘要: 以正弦波电流为激励信号测量接地网接地阻抗时，由于电压线、电流线之间不可避免的存在平行共线，由此产生的互感耦合会导致接地阻抗测量结果偏高，影响接地网安全性能评估。为解决此问题，提出了一种基于组合波工程化测量消除引线互感的接地阻抗测量方法，用方波电流测量接地阻抗电阻分量，用正弦波测量接地阻抗模值，在测量现场通过改变平行共线距离获得不同互感耦合强度的测量值，解析剔除互感耦合分量后，获得准确的接地阻抗测量值。在110kV变电站现场通过夹角法、反向法测量，并与土壤分层的接地网模型仿真结果对比，组合波工程化测量结果与接地阻抗仿真值误差仅为1%。

Abstract:

Abstract：When measuring the grounding impedance of grounding grid with sine wave current as excitation signal, due to the inevitable parallel co-linearity between voltage lines and current lines, the resulting mutual inductance will lead to the high measurement result of grounding impedance, and affect the safety performance evaluation of grounding grid. In order to solve this problem, a grounding impedance measurement method based on combined wave measurement to eliminate lead mutual inductance is proposed. The grounding impedance resistance component is measured with square wave current and the grounding impedance modulus is measured with sine wave current. The measured values of different mutual inductance coupling strength are obtained by changing the parallel col-linear distance at the measurement site. After the mutual inductance coupling component is analytically eliminated, accurate grounding impedance measurements can be obtained. Comparing the grounding grid measurement results at the 110kV substation site by angle method and reverse method with the simulation results based on layered soil model, the the error between the combined wave method measurement results and the simulation value of grounding impedance is only 1%.