Cost-effective synchronization strategy for distributed generators in islanded microgrids

A microgrid (MG) is an effective way to integrate various distributed generators (DGs) into a power distribution system. The synchronization of DG voltage with MG voltage is indispensable to prevent inrush currents before connection to a MG system and for working in parallel with other DGs in the MG. In the past, synchronization in terms of both phase and magnitude was realized using additional voltage sensors to measure the MG voltage. However, this increased the system cost. In this paper, a cost-effective synchronization strategy is proposed to allow a DG to connect with an islanded MG system without any additional voltage sensors. The feasibility and effectiveness of the proposed strategy were validated by experiment with a scaled-down islanded microgrid.