煤矿地面660V电网中性点接地方式和选择性漏电保护

就当前能源部在煤矿开展洗煤厂和地面生产系统低压电网升压660V的工作中,从现有老矿老厂升压改造的经济合理性,中性点高阻接地方式的适应性,以及高阻接地电阻值和专用接地变压器和专用电抗器的接线、容量等特点作了阐述,举例介绍了一种具有选择性强、灵敏度高、自检等功能全的实用线路。

THE NEUTRAL GROUNDING MODE AND SELECTIVE LEAKAGE PROTECTION IN 660V ELECTRIC NETWORK OF THE MINE SURFACE

In the light of that the Ministry of Energy is carrying out the work of stepping up the voltage of low voltage electric network of the coal washery and the surface production system in collieries to 660v. This article lakes an elaboration on ground of the economical rationality of step-up voltage and reformation of the existing old nine and old plant. the adaptability of the high inpedence neutral grounding mode and high grounding resistance, and the characteristics of connection and capacity of special grounding transformer and special reactor etc, and also introduces, with examples, a practical full function circuit with strong selectivity,high sensitivity and self checking etc.