微电网的有限区域集成保护

Limited Area Integrated Protection of Microgrid

针对低压微电网的特点和保护要求,提出了一种基于有限区域集成的微电网保护新方案。通过将微电网以母线为依据分割为若干个区域,在每个区域设置一个有限区域保护单元。首先提取每个区域内各馈线的正序故障分量电流,通过比较区域主馈线与各从馈线的正序故障分量电流相角差,可以确定故障区域,其次比较故障区域内各从馈线之间的正序故障分量电流相角差,从而判定故障线路。该方案能够准确排查和定位故障区域,快速隔离故障线路,可靠切除微电网内部故障。文中利用PSCAD/EMTDC软件进行仿真分析,仿真结果验证了所述保护方案的正确性和可行性。

In consideration of the characteristics and requirements of low voltage microgrid protection,a new microgrid protection scheme based on limited area integration is proposed.The microgrid is divided into several areas based on the bus node,and the limited area protection unit(LAPU)is installed in each area.First,the positive-sequence fault components of each feeder current are extracted,and the fault area can be confirmed by comparing the phase angle difference between the main feeder and slave feeders.Then the fault line can be confirmed by comparing the phase angle difference of the positive-sequence fault current component between different slack feeders.The scheme is capable of inspecting and locating the fault area accurately,isolating the fault line quickly and eradicating the internal fault of microgrid reliably.The PSCAD/EMTDC software is used in the simulation analysis,and the correctness and effectiveness of the protection scheme is verified by simulation results.