中性点经消弧线圈接地系统中柔性环网控制装置接地故障分析  

Grounding Fault Analysis of Flexible Loop Network Control Device in Neutral Point Grounding System with Arc Suppression Coil

作　　者：姜田贵[1] 谢晔源[1] 李洪涛[2] 连建阳[1] 邱德锋[1] 

机构地区：[1]南京南瑞继保电气有限公司,南京市211002 [2]国网北京市电力公司,北京市100031

出　　处：《电力建设》2016年第5期146-152,共7页Electric Power Construction

基　　金：国家高技术研究发展计划项目(863计划)(2015AA050102)~~

摘　　要：中性点经消弧线圈接地系统采用无连接变压器接线方式的柔性环网控制装置与交流系统共用接地支路,装置的接地故障特性不同于常规有连接变压器的换流装置,需要对其接地故障特性进行分析,为装置故障诊断、保护的设计提供依据。分析了基于模块化多电平换流器的柔性环网控制装置交流侧单相接地故障时的故障机理,阐述了故障后装置故障侧和非故障侧换流器的电气量特征,分析了柔性环网控制装置直流单极接地故障特性,推导了故障后换流器在不同工作模式下故障电流的解析方程,指出在消弧线圈接地支路增加阻尼电阻可以加快故障电流衰减。通过建立的基于模块化多电平换流器的柔性环网控制装置PSCAD/EMTDC仿真模型,验证了本文故障特性分析的正确性和有效性。Flexible loop network control device without transformer shares the same ground branch with the AC system,whose neutral point is grounded by arc suppression coil. The grounding fault characteristic of the device is different from that of the conventional device with transformer. It is necessary to analyze the characteristics of the grounding fault,which provides the basis for fault diagnosis and protection design. This paper analyzes the fault mechanism of the single phase grounding fault in the AC side of the flexible loop network control device based on the modular multilevel converter,and describes the electrical characteristics of the fault side and the non-fault side of the converter. Then,this paper analyzes the characteristics of DC monopolar grounding fault in the flexible loop network control device,derives the analytical equations of fault current in different operating modes of the converter,and points out that the increase of damping resistance of arc suppression coil grounding branch can speed up the fault current attenuation. Finally,this paper constructs the PSCAD /EM TDC simulation model of the flexible loop network control device based on the modular multilevel inverter,and verifies the correctness and validity of the fault characteristic analysis.

关 键 词：柔性环网控制装置 消弧线圈接地 模块化多电平换流器 单相接地故障 直流单极接地故障 

分 类 号：TM721[电气工程—电力系统及自动化]