Energy management strategy for renewable backup supply

This paper proposes an energy management strategy for backup supply system which efficiently coordinates power flow among renewable energy resources within the DC microgrid. To ensure reliable power at the supply side, the fuel cell is employed to work as a base-load supply and the lead-acid battery storage is used to buffer the power imbalance between renewable generation and load demand. The fuel cell system is interfaced with a 450W current-fed full-bridge isolated DC-DC converter for controlling the output power of the fuel cell. The lead-acid battery bank is interfaced with a 1.5kW dual-active-bridge bidirectional DC-DC converter for buffering the power difference among renewable energy resources and loads. The hybrid renewable energy converters are coordinated by CAN-Bus communication. Experimental tests are conducted to validate the function of the energy management control and strategy.