新型微电网外部短路故障保护方案  

New protection scheme for external short-circuit fault of microgrid

作　　者：童荣斌 牟龙华[1] 庄伟[1] 

机构地区：[1]同济大学电气工程系,上海201804

出　　处：《电力系统保护与控制》2014年第5期78-84,共7页Power System Protection and Control

基　　金：上海市科学技术委员会资助(12ZR1451300);上海市教育委员会科研创新项目(11CXY12)

摘　　要：结合微电网与配电网的隔离策略,提出了一种基于正序故障分量原理的新型微电网外部短路故障保护方案。该原理分别提取微电网与配电网之间的联络线两端的正序故障分量进行阻抗计算,然后利用阻抗角构成的新判据确定是否发生微电网外部故障。该原理无需考虑负荷电流和故障电阻的影响,克服了微电网故障时短路故障电流小以及潮流双向流动的问题。同时采用正序故障分量电流幅值差动保护作为阻抗角保护判据的启动判据,构成了一套完整有效的微电网外部短路故障保护方案。用PSCAD/EMTDC建立一个连接配电网的微电网仿真模型,进行各种短路故障仿真,仿真结果验证了所述保护方案的正确性和有效性。Considering the isolation strategy of microgrid and utility power, the paper proposes a new protection scheme for external short-circuit fault of microgrid＇ based on positive-sequence fault component principle. The principle extracts the positive-sequence fault components of two terminals of tieline between microgrid and utility power and calculates their impedances, then uses the impedance angle as new fault criterion to identify the external fault of microgrid. Without considering the load current and fault resistance, the principle overcomes the bidirectional characteristic and finiteness of short-circuit current. Meanwhile, the current magnitude of positive-sequence fault components is used as trigger criterion, thus the comprehensive protection scheme is presented. A microgrid model connected to utility power is built by PSCAD/EMTDC, and all kinds of fault type are simulated, the simulation result shows that the protection scheme is correct and effective.

关 键 词：微电网 隔离策略 外部故障 正序故障分量 

分 类 号：TM773[电气工程—电力系统及自动化]