附加直流电源的电缆绝缘在线监测新方法

New Method to Measure One Phase Grounding Current of Mine Electric Power Network

在现有附加直流电源型漏电保护装置的基础上 ,提出了一种利用附加直流电源实现在线监测电缆线路绝缘电阻的新方法 ,采用该方法可实现分支电缆出线对地绝缘电阻的在线监测 ,还可实现井下电网的选择性漏电保护。

The paper introduced a new method to measure one phase current of mine electric power network which is a safe and practical method. The method is to have a resistance and a current meter in between one phase of the power network and ground. Then in between the neutral point and ground, there will be a displaced current and 0 voltage. With a phase voltage or a line voltage measured from the power network and 0 voltage or a current measured from the current meter, a current at a single phase directly grounded or a single phase grounded current can be calculated with a formula. This current is made from a calculation and it is called a indirect measurement method. This is more safe without a harmful to the equipment and human than the direct measurement with a meter directly connected the power network. This method has been applied to measure single phase ground current of many mine electric power networks with satisfactory results. As for a network of 6 kV, the resistance value can be 500～1000Ω, the power can be 2～3 kW and the current mater can be 5 or 10 A.