With the increasing penetration rate of renewable energy,the inertia of the power grid gradually decreases,and the transient support capacity is seriously insufficient. It brings a series of security problems to the power grid. A distributed grid-connected topology cascaded by energy storage and open-winding permanent magnet synchronous generator (OW-PMSG) is proposed in this paper. By the topology,the renewable energy can be consumed. At the same time,the diesel engines can provide power backup and inertia support. By modelling the OW-PMSG and analyzing the power flow vector,a power transfer strategy based on the source-grid phase closed-loop control is designed to achieve stable synchronous operation of the generator. Based on this strategy,the energy storage converter can have synchronous generator characteristics,which achieves further improvement of grid inertia and transient support capability. The simulation results verify the feasibility of the proposed control strategy.