Improving the microgrid fault ride-through capability and enhancing the transient performance of microgrid operation due to voltage sags is of great importance. This paper investigates the ride-through capability and feasibility of integrating a mutual inductance between the main grid and the microgrid under short circuit condition. The fault ride-through capability of the microgrid DGs is examined by placing the mutual inductance at PCC to suppress the fault current and to maintain the microgrid grid connected. This inductance requires no control to operate in which the sudden current increase is the key point of its operation. The microgrid DGs can operate successfully in grid-connected mode without reactive power support during the voltage sag duration. The effectiveness of the inserted mutual inductance has been validated considering two case scenarios of the microgrid power flow condition. The proposed methodology shows promising results, in which it confirms the applicability of the mutual inductance in riding through the fault current and maintaining the microgrid DG operation in the grid-connected mode. SimPowerSystems and PLECS toolboxes of Matlab/Simulink software are utilized to implement the proposed work.

提高微电网故障穿越能力，增强微电网因电压暂降运行的暂态性能具有重要意义。本文研究了在短路条件下在主电网和微电网之间集成互感的穿越能力和可行性。通过在 PCC 处放置互感来抑制故障电流并保持微电网连接，检查微电网 DG 的故障穿越能力。该电感无需控制即可工作，其中电流突然增加是其工作的关键点。在电压暂降期间，微电网 DG 可以在没有无功功率支持的情况下以并网模式成功运行。考虑到微电网功率流条件的两种情况，已经验证了插入互感的有效性。所提出的方法显示出可喜的结果，其中证实了互感在穿越故障电流和维持微电网 DG 在并网模式下运行方面的适用性。Matlab/Simulink 软件的 SimPowerSystems 和 PLECS 工具箱用于实施所提出的工作。