基于参数闭环控制的配电网柔性接地消弧方法  

Flexible-grounding Arc-suppression Method for Distribution Network Based on Parameter Closed-loop Control

作　　者：周江华[1] 万山明[1] 张勇[1] ZHOU Jianghua;WAN Shanming;ZHANG Yong(State Key Laboratory of Advanced Electromagnetic Engineering and Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]华中科技大学强电磁工程与新技术国家重点实验室,武汉430074

出　　处：《高电压技术》2020年第4期1189-1197,共9页High Voltage Engineering

摘　　要：针对配电网小电流接地系统在发生单相接地故障之后故障点残余电流无法实现全补偿从而影响消弧性能的问题,在中性点柔性接地的技术基础上提出了基于零序导纳参数闭环控制的有源消弧方法。分析了开环电流补偿指令将受到参数测量误差的影响,理论推导了柔性接地系统故障前后零序导纳参数的变化规律,并以此作为参数闭环控制的依据,通过参数闭环控制策略提高了故障点电流补偿的准确性。在考虑高斯白噪声(50 dB)干扰的仿真算例中,采用参数闭环控制的结果(接地电流为0.25 A)优于参数开环控制的结果(接地电流为1.35 A);在金属性接地的仿真算例中,采用参数闭环控制的结果(接地电流为0.38 A)优于电压闭环控制的结果(接地电流为4.51 A)。仿真与实验结果表明了所提方法能够准确补偿故障点接地电流的有功分量和无功分量,降低了系统对零序互感器测量精度的要求,且适用于不同接地过渡电阻的故障情况,实现了接地故障的快速处理与可靠消弧。In consideration of the problem that residual current at a fault point cannot be fully compensated when single-phase grounding faults occur in a distribution network, an active arc suppression method based on zero-sequence admittance parameter closed-loop control was proposed on the basis of neutral point flexible grounding technology. The influence of parameter measurement on open-loop current compensation instruction was analyzed, and the change rule of zero-sequence admittance parameters before and after faults of a flexible grounding system was deduced. The accuracy of fault point current compensation was improved by using the method of parameter closed-loop control. In a simulation example where the interference of Gauss white noise(50 dB) is taken into account, the result of parameter closed-loop control(grounding current is 0.25 A) is better than that of parameter open-loop control(grounding current is 1.35 A). In a simulation example of low earthing resistance grounding, the result of parameter closed-loop control(grounding current is 0.38 A) is better than that of voltage closed-loop control(grounding current is 4.51 A). Through simulation and experimental verification, this method can be adopted to effectively compensate the active and reactive components of the grounding current at the fault point, and to reduce the requirement for the measurement accuracy of zero-sequence transformer, and is suitable for the fault situations of different grounding transition resistors, thus realizing the rapid treatment of grounding fault and reliable arc suppression.

关 键 词：配电网 有源消弧 中性点柔性接地 单相接地故障 闭环控制 

分 类 号：TM862[电气工程—高电压与绝缘技术]