变电站直流电源绝缘在线监测新方法  

On-line insulation monitoring of substation DC power supply

作　　者：王瑞祥 刘峰 熊小伏[2] 王尉军[2] 

机构地区：[1]六盘水供电局,贵州六盘水553000 [2]重庆大学输配电装备及系统安全与新技术国家重点实验室,重庆400044

出　　处：《电力自动化设备》2009年第12期65-67,93,共4页Electric Power Automation Equipment

摘　　要：指出了现有变电站直流电源绝缘监测没有直流电源系统历史信息等不足之处,提出基于智能传感器、零点滤波器等技术的直流电源绝缘在线监测新方法。该方法提出在各供电回路装设智能传感器检测故障漏电流,利用通信网络采集各漏电流信号送至监控主机,经过零点滤波器等数字信号处理手段去除干扰成分后,可有效地确定接地回路和接地点。监控主机还可实时监测各支路直流绝缘的变化,根据历史数据对绝缘下降趋势做出预测。提出了对漏电流采样值越限报警和电流变化量越限报警的判据,并对零点数字滤波进行了仿真,通过现场试验验证了所提出方法的正确性。The disadvantages of present insulation monitoring of substation DC power supply system are pointed out and an online insulation monitoring method based on intelligent sensor and zero-crossing filter is proposed for DC power supply. The fault leakage current is detected by the intelligent sensors installed on every power supply circuits ,and then sent to the monitoring computer via communication networks,which are processed by zero- crossing filter to eliminate the interference components. The grounding circuit and point are then effectively determined. The DC insulation variation of each branch is also monitored in real time and its downward trend is forecasted based on the historical data. The alarm ＇criteria of instantaneous current limit violation and current change rate violation are put forward. The zero- crossing filter is also simulated. The validity of the proposed method is proved by on-site test.

关 键 词：直流电源 绝缘在线监测 漏电流 检测判据 零点滤波器 

分 类 号：TM934.3[电气工程—电力电子与电力传动]