论文部分内容阅读
一、前言矿井电网运行经验表明:无论是高压电网还是低压电网,都容易发生单相接地故障。其事故率约占矿井电气事故的60～70％。特别是6kV电网,有时会因单相接地故障引起“两相异地短路”造成6kV电缆放炮,如事故发生在煤矿井下,有可能引起瓦斯爆炸。为杜绝上述危险,《煤矿安全规程》规定,在矿井供电网中必须安装漏电保护装置。要求在地面变电所应装有选择性漏电保护装置;在井下中央变电所向移动变电站馈
I. Introduction Mine operation experience shows that: whether high-voltage power grid or low-voltage power grid, are prone to single-phase ground fault. The accident rate accounts for about 60 ~ 70% of mine electrical accidents. Especially 6kV power grid, sometimes caused by single-phase ground fault “two different short-circuit” caused by 6kV cable blasting, such as the accident occurred in the coal mine, may cause gas explosion. In order to eliminate the above-mentioned danger, “Coal Mine Safety Regulations” stipulate that earth leakage protection devices must be installed in the mine power supply network. Requirements in the ground substation should be equipped with selective leakage protection device; in the underground substation to the mobile substation feed