Fully distributed energy management strategy for DC bus charging stations with three charging modes

Although electric vehicles supplied through distributed generators (DGs) have been universally researched to reduce CO₂ emissions, the accurate current sharing regarding islanded multi-bus DC charging stations considering three charging modes of electric vehicles, i.e., constant current mode, constant power mode and constant voltage mode, is rarely realized. Meanwhile, the demand for structure information of global communication networks and the high communication bandwidth have hindered the large-scale development of islanded multi-bus DC charging stations. Based on this, a fully distributed dynamic event-triggered consensus control without global structure information is proposed to realize accurate current sharing among DGs. Firstly, the system model of multi-bus DC charging stations considering electric vehicles with three charging modes is built, and the primary virtual impedance controller is designed to eliminate the low-frequency oscillation caused by the electric vehicle with constant power charging mode. Furthermore, the state-space function considering power coupling among different DC buses is built, which is a fundamental preconditioning for the subsequent controller design. Based on the built state-space function, the fully distributed dynamic event-triggered consensus control is proposed to achieve accurate current sharing among DGs considering three charging modes. Therein, coupling weights are introduced to solve control gains without global communication structure information. Moreover, theoretical demonstration of no Zeno behavior is provided. Finally, the proposed fully distributed control is verified by simulation and experiment results.