弱联络海岛微电网群缺乏陆地电网支撑，系统潮流动态不定、故障电流水平低，导致保护设计困难。为此，利用节点电压信息构造虚拟漏电流揭示了正常扰动、区内故障、区外故障工况下线路两端节点的虚拟漏电流特性，基于此建立了故障区段检测判据与故障距离计算模型，提出了适应弱联络场景的海岛微电网群故障检测与定位方法。最后，仿真结果表明，不同故障电阻、故障位置、故障类型工况下所提方法均能准确判别故障线路与故障相，微电网内主干线路和微电网间互联线路的故障定位误差均小于5 %。

Weakly connected microgrid lacks terrestrial grid support, resulting in unstable system power flow dynamics and low fault current levels, and leads to complicate protection design. To address this, virtual leakage current is constructed using node voltage information to reveal the characteristics of line-end node virtual leakage current under normal disturbances, internal fault and external fault conditions. Based on this, a fault section detection criterion and fault distance calculation model are established, a fault detection and location method suitable for weakly connected microgrid is proposed. Finally, simulation results demonstrate that the proposed method accurately identifies faulted lines and phases under varying fault resistances, locations, and types, with fault location errors between main grid lines and microgrids interconnected lines remaining below 5 %.