In this paper, a novel microinverter for a residential energy storage system is designed based on the series resonant dual-active-bridge (SRDAB), with a full-bridge on the primary side, and a bidirectional half-bridge as well as split resonant capacitor on the secondary side. Meanwhile, the corresponding modulation strategy is also optimized. Firstly, the time-domain analysis method is used to establish a time-domain model. Furthermore, taking the root-mean-square (RMS) of the resonant current as the optimization goal, the modulation strategy of the topology is designed, and constraints for zero-voltage-switching (ZVS) are further added to reduce the switching losses. Finally, the particle swarm optimization (PSO) algorithm is used to solve the numerical solution of the modulation strategy, and its feasibility is verified by simulation and experimental results.