摘要
含电压平衡器的双极性直流微电网能够实现多电压等级的负荷供电,应用前景广泛,但仍缺乏相应的直流馈线故障隔离与定位方案。为此,引入故障场景下的选极可靠系数,建立了直流馈线单极和极间短路故障灵敏检测判据,并通过电源出口断路器的快速跳闸和并网变流器出口断路器的延时跳闸相互配合,实现了故障元件准确隔离和故障区段精准定位。最后,改进了直流微电网多储能DC-DC变流器的电压控制策略,由此形成了应对直流馈线故障的完整保护方案。PSCAD仿真结果表明,所提方案能够实现不同直流馈线故障的可靠辨识与区段定位,结合相应控制策略可显著提高单极故障下非故障极的运行稳定性和供电连续性,且经济性较优。
A bipolar DC microgrid containing voltage balancers can realize multiple-voltage power supplies with broad application prospect,but still lacks specific DC feeder fault isolation and location schemes.Therefore,a reliability coefficient for fault pole selection under fault scenarios is introduced to establish the detection criteria for the single pole and inter-pole short circuit faults of DC feeders.The fault element is accurately isolated and the fault section is precisely located through the cooperation between the fast tripping of the DC Circuit Breakers(DCCBs)at the outlets of power sources and the delayed tripping of the DCCBs at the outlet of the grid-connected converter.Finally,the voltage control strategies of the DC-DC converters of multiple energy storages in DC micro grids are improved,and a complete protection scheme for DC feeder faults is formed.The PSCAD simulation results show that the proposed scheme can realize reliable identification and section location of different DC feeder faults,and combined with the corresponding control strategy,the operational stability and supply continuity of the non-fault pole under a unipolar fault condition is significantly improved.In addition,the economic performance is relatively good.
作者
王阳光
张孝军
徐宇新
黄勇
叶雨晴
马啸
李正天
吴宇奇
WANG Yangguang;ZHANG Xiaojun;XU Yuxin;HUANG Yong;YE Yuqing;MA Xiao;LI Zhengtian;WU Yuqi(State Grid Hunan Electric Power Co.,Ltd.,Changsha 410004,China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology(Huazhong University of Science and Technology),Wuhan 430074,China)
出处
《电力系统保护与控制》
CSCD
北大核心
2021年第4期81-88,共8页
Power System Protection and Control
基金
国家自然科学基金面上项目资助(51877088)
国网湖南省电力有限公司科技项目资助(5216A018007W)。
关键词
直流微电网
故障定位
电压平衡器
直流限流器
直流断路器
DC microgrid
fault location
voltage balancer
DC fault current limiter
DC circuit breaker
