中文摘要：

为解决分布式电源微网在并网运行下快速感知公共配电网单相接地短路故障,确保公共连接点PCC处的有效保护,提出了一种故障分量加dq坐标变换的单相接地短路识别方法。利用PCC处的工频三相电压推算故障相故障分量电压,判别是否发生不对称短路故障,对三相故障分量电流进行正序、负序及零序分解,利用故障分量电压的有无决定是否进行零序电流补偿并进行dq变换,构造出故障电压、电流特征量判定单相接地短路故障,根据正、负序故障分量电流相位关系实现故障选相。仿真结果表明,基于故障分量和dq变换的单相接地故障识别方法是有效的和实用的,该方法能准确识别单相接地故障,实现故障选相,从而为微网的运行提供参考依据。

英文摘要：

When a microgrid composed of distributed generators is controlled in grid-connected operation mode, its rapid reaction to the single-phase ground fault in the distributed network as well as the effective protection of PCC （Point of Common Coupling） should be required. A method for identifying single-phase ground fault by using fault components and dq transformation is presented. Fault component voltage of fault phase can be calculated to identify the unsymmetrical short circuit fault according to the three-phase voltages of PCC, and then the three sequence fault components can be obtained by using symmetrical component law. Zero sequence current compensation is conducted in case of fault component voltage in dq frames. Fault characteristics are constructed to identify single-phase ground fault. Fault phase selection is decided by phase angle of positive and negative fault component. Simulation test is presented to demonstrate the effectiveness of the proposed method. Single phase ground fault identification and fault phase selection are realized. All aspects are proposed for improving microgrid in better operating mode.