煤矿高压电缆绝缘电阻的微分差值在线监测方法

Differentials difference value online monitoring method for insulation resistance of mining high voltage cable

为了实时在线监测矿用高压电缆的绝缘状态,准确获取电缆线路绝缘参数,建立了电缆线路的对地等效电路模型,提出微分差值法的在线监测原理,设计了一种矿用高压电缆绝缘在线监测系统。采用高性能的嵌入式处理器结合软件平均值滤波法,计算出表征高压电缆绝缘状态的特征量绝缘电阻和分布电容值,在电缆线路正常供电情况下,对电缆线路的首末端电流信号和电压信号的瞬时值进行精确测量和调理。同时,通过以太网控制器实现电缆线路绝缘状态的远程监控。实验结果表明:监测系统可以实时监测电缆线路的对地绝缘电阻和等值电容,测量误差在3%以内。

The paper is motivated the need for online monitoring of insulation condition of mining high voltage cable in real time and obtaining accurate insulation parameters. The research consists of developing equivalent circuit model of cable to ground; providing the differentials difference value; and explaining its on-line monitoring principle in detail; designing the system of mining high voltage cable insulation resistance monitoring; in normal power supply,computing the cable insulation properties of insulation resistance and equivalent capacitance by employing a high-performance embedded processor combined with average value filter method; accurately measuring the instantaneous voltage and current of cable ends and signal conditioning circuits and simultaneously using an Ethernet controller to establish the monitoring system capable of real-time and networked monitoring and management of operation status of mining high voltage cable. The experiment indicates that the monitoring system is able to monitor the realtime data of insulation resistance and equivalent capacitance,combined with management system,with the relative error of automatic inspection of less than 3%.