新型接地故障基波电流全补偿柔性控制系统  

New Flexible Control System of Full Compensation Single-phase Ground Fault Fundamental Current

作　　者：刘宝稳[1] 马宏忠[1] 沈培锋[2] 陈冰冰[2] 

机构地区：[1]河海大学能源与电气学院,江苏省南京市211100 [2]江苏省电力公司南京供电公司,江苏省南京市210008

出　　处：《中国电机工程学报》2016年第9期2322-2330,共9页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51177039);江苏省电力公司科技项目(J2014055;J2015054)~~

摘　　要：单相接地故障电流和间歇性弧光过电压严重影响供电系统的安全,为此提出一种偏置接地柔性控制系统,其具有中性点不接地系统和谐振接地系统的优点。中性点不接地系统正常运行时加入偏置元件,实现电网电容电流和绝缘电阻的精确测量,测量结果不受电网不对称度的影响;当发生单相接地故障后,根据故障前后零序电压和测得的线路分布参数计算故障电流,比较各相电压与故障电流的相位实现故障选相,选相结果不受过渡电阻的影响;然后在故障相的超前相对地接入一阻感性补偿元件,补偿元件可实现接地故障基波电流的全补偿,可有效地将故障相电压钳制为零,消除电弧重燃的可能性。由于高阻接地故障的接地电流小、零序电压位移度小,不满足电弧自燃的条件,因而根据接地电流实际测量值柔性控制补偿元件的投切,为配电网接地故障消弧提供新的理论。Single-phase-ground fault current and intermittent-arc over-voltage jeopardize the safety of the power systems seriously. This paper proposed a bias earthed flexible control system, which has both advantages of ungrounded systems and resonant grounded systems. In the normal state of ungrounded systems, the capacitive current and the insulation resistance can be measured by adding a bias-element. The measurement results cannot be affected by the asymmetry of network. When single-phase ground fault occurs, fault current could be calculated. And the fault phase can be selected by comparing the phase-angle between the phase-voltage and the fault current which cannot be influenced by the transition resistance. Full-compensated bias-element which can fully compensate the fault current is connected with the wire advanced the fault phase. Then the fault phase voltage can be suppressed to zero effectively. When the low-current faults（LCFs）occurs, the fault current and the zero-sequence voltage displacement are both small, which cannot meet the conditions to trigger an arc naturally. Consequently, flexible control of bias elements can be achieved based on the actual value of ground fault current. Analysis and simulations demonstrat the novel fault arc suppression method.

关 键 词：偏置接地系统 单相接地故障选相 柔性控制 全 补偿 分布参数测量 接地电流 

分 类 号：TM74[电气工程—电力系统及自动化]