煤矿井下高压电网过流保护整定计算方法的改进研究

为了提高煤矿过流保护的可靠性,针对各级变电所6 kV出线开关,给出了一种改进的过流保护整定计算方法。分析了传统方法的不足,并详细介绍了新方法的整定计算过程。新方法中用线路载流量对定时过流与过负荷保护进行了整定,并介绍了瞬时速断保护是否设置的判定方法。以定时过流保护为例,介绍了灵敏度不合要求时的处理方法。最后以河南大有能源某煤矿局部供电系统为例进行了计算论证,并进行了分析。结果表明,新方法是有效和实用的,能够保证过流保护装置可靠动作,从而提高过流保护的可靠性。

Improvement and research on the setting calculation method of overcurrent protection of the underground high-voltage distribution network of coal mine

In order to improve the reliability of overcurrent protection of coal mine, for 6 kV outlet switch of substation of all levels, this paper gives an improved setting calculation method of overcurrent protection. It analyses the shortcomings of traditional method and introduces setting calculation process of the new method. The new method uses the line ampacity to set the timing overcurrent and overload protection, and introduces the judging method of setting instantaneous overcurrent protection or not. Taking the timing overcurrent protection as an example, it introduces the processing method when sensitivity does not meet the requirment. Finally, the local power supply system of a mine of Henan Da You Energy is taken as an example to calculate and demonstrate, and then make analyses. The results show that the new method is effective and practical, and it can guarantee the overcurrent protection device action reliably, so as to improve the reliability of overcurrent protection.