摘要
高压直流断路器在直流系统保护中起着重要作用。针对现有直流断路器在经济性、合闸电弧问题和快速性方面不能兼备的缺陷,提出了一种强制换流型混合式高压直流断路器拓扑。所提方案的拓扑结构中引入了1个绝缘栅双极晶体管(insulated gate bipolar transistor,IGBT),用来配合隔离开关进行合闸操作;引入二极管组并将平波电抗器均分在断路器两侧,以减小对避雷器的压力,延长避雷器的使用寿命;电力电子支路用子模块级联拓扑,避开了大规模IGBT动态均压的技术难题。基于所提拓扑设计了10kV直流断路器,对正常运行以及故障切除、故障恢复合闸下的运行情况进行了分析及仿真,同时与含ABB方案的两种典型方案进行了比较。仿真结果表明:基于所提拓扑的直流断路器最快切除故障电流时间为3.63 ms,开断电流容量为4.09 kA,正常合闸机械支路端电压为0,实现了无弧合闸,IGBT使用数量较ABB方案减半,避雷器吸收能量较传统方案减半,经济性较好,符合直流断路器性能要求。该结果验证了所提拓扑结构具备可行性。
High voltage DC breaker is the core device of DC grid protection.In accordance with the shortcomings of the existing economy,closing arc problem and rapidity,we propose a scheme of hybrid high voltage DC circuit breaker with forced current commutation.An IGBT was introduced in the proposed topology to eliminate the coordination problem of the circuit breaker with disconnecting switch in closing operation.Diode groups were introduced in the proposed topology,and the current limiting inductor is divided into two parts,which are respectively installed at both ends of the circuit breaker.In this way,the fault clearing time and stress of arrester can be decreased,which can prolong the useful life of the arrester.The cascaded submodules are adopted in solid-state switch branch,which can reduce the difficulty of engineering technology.A 10 k V DC circuit breaker was designed based on the proposed topology.The fault clearing,closing and opening process are analyzed and simulated.At the same time,it is compared with two typical schemes including ABB topology.The simulation results show that the fault current clearing time is 3.63 ms;the breaking current capacity was4.09 kA;the voltage at mechanical branch in closing process is zero,and the arc-free closing is realized.The number of IGBTs used is halved compared with the ABB scheme;the energy absorbed by the arrester is halved compared with the conventional scheme,and the economy is better.The results verify the feasibility of the proposed topology structure.
作者
王辉
马超
郝全睿
韩国庆
WANG Hui;MA Chao;HAO Quanrui;HAN Guoqing(Department of Electrical Engineering,Shandong University,Jinan250061,China;State Grid Tianjin Electric Power Company,Tianjin300010,China)
出处
《高电压技术》
EI
CAS
CSCD
北大核心
2019年第8期2425-2433,共9页
High Voltage Engineering
基金
国家重点研发计划(2017YFB0902400)~~
关键词
直流电网
混合式直流断路器
强制换流
短路故障
拓扑结构
DC grid
hybrid DC circuit breaker
forced current commutation
short circuit fault
topological structure
