不拆解接地线的GIS导电回路电阻快速测量方法研究

GIS设备在安装及检修过程中,需要利用直流压降法来检测导电回路电阻,以检查断路器、隔离开关等设备的连接状况。但是,直流压降法在测量时需要拆解接地线,其操作繁琐、工作效率低。同时,还存在损伤本体结构,以及从周围带电设备感应出高电压的可能。为此,基于GIS设备的拓扑结构,提出了一种不拆解接地线的GIS导电回路电阻快速测量方法。该方法首先将GIS网络提取成多阶T型阻抗网络,通过节点电压方程和回路电流方程建立对应的阻抗矩阵。通过施加两次不同接线方案的直流激励源来求解该阻抗矩阵。同时,还分析了接地网络分流和三相相间分流对测量结果的影响,并在此基础上提出了该方法的激励源施加方案。经实例验证,该方法的测量结果与直流压降法的测量结果相似,同时还可有效提高工作效率,对同类型GIS设备的导电回路电阻测量具有参考意义。

Research on fast measuring method of GIS circuit resistance without removing grounding wire

During the installation and maintenance of GIS equipment, DC voltage drop method is needed to measure the resistance of the GIS circuit in order to check the connection status of circuit breaker, disconnecting switch and other equipment. However, DC voltage drop method needs to remove the grounding wire when measuring, which is cumbersome and inefficient. At the same time, this method may damage the structure of GIS equipment and induce high voltage from the surrounding charged equipment. Therefore, based on the topology of GIS equipment, a fast measuring method of GIS circuit resistance without removing the grounding wire was proposed in this paper. The GIS network was extracted into a multilevel T-type impedance network, and the corresponding impedance matrix was established through the node voltage equation and the loop current equation. The impedance matrix is solved by applying DC excitation sources of two kinds of wiring schemes. And the influences of earth network shunting and three-phase interphase shunting on the measurement were analyzed, and on this basis, the scheme of applying excitation source was proposed. After validating, the measurement results of proposed method were similar to DC voltage drop method. This method can improve working efficiency. It has reference significance for measuring circuit resistance of the same type of GIS equipment.