直流系统绝缘监测的直流漏电流法改进方案  

Modification of the DC Leakage Method for DC System Insulation Monitoring

作　　者：赵梦欣[1] 陈国峰[2] 余伟成[1] 

机构地区：[1]中国电力科学研究院,北京市100192 [2]北京市电力公司,北京市100031

出　　处：《电力系统自动化》2009年第14期83-88,107,共7页Automation of Electric Power Systems

摘　　要：支路巡检是确定接地点前的重要步骤。针对传统直流漏电流法所引发误报和漏报,文中归纳为5个方面的原因,并提出了一套改进方案。在分析漏电流传感器中电流分量和直流网络中各级母线电压差的基础上,通过对算法的优化,本方案不仅提高了测量精度,而且克服了传感器零点漂移的影响,回避了下级母线接地电压表导致的泄漏电流。通过对闭环状态下穿越电流和开环状态下电流分流的分析,改进的故障支路指示方式取代了传统的漏电流决定绝缘电阻、决定报警的工作方式,避免了对运行人员的误导。模拟试验验证了该方案算法的正确性,以及与多种母线绝缘监测方式配合的适应性。Branch scan is an important approach to locate insulation faults. Nevertheless the conventional DC leakage method often makes false alarms or omissions, which is resulted from 5 factors in the malfunction. There is a need for modification. Based on the analysis of current components through leakage sensors and voltage drops between buses, the optimized algorithm can significantly improve the measurement accuracy, without the disadvantage of zero-drift in leakage sensors, and without the leakage from sub-bus to earth voltage meters. Through analysing the pass-through current to a sub-bus and the current splitflow into a closed loop, the new method outperforms the conventional residual current warning based method which often misguides operators. Experimental results show validity of the algorithm and adaptability to diversiform omni-bus insulation monitoring methods.

关 键 词：绝缘监测 支路巡检 直流漏电流法 零点漂移 泄漏电流 穿越电流 闭环 

分 类 号：TM862[电气工程—高电压与绝缘技术]