Abstract: This paper demonstrates the proposed functionality of a power electronics-based energy management system (EMS). The EMS includes batteries and a digitally controlled single-phase voltage source inverter (VSI), which can be controlled as a current source or a voltage source depending on the status of the ac grid and the userís preference. The proposed EMS can give guarantees that the critical loads are powered when the ac grid fails; in which case, the VSI is controlled as a voltage source. It also expect peak power control by supplying battery power to the local loads while they are powered by the ac grid if the loads get large. The electricity cost savings will be accomplished by peak shaving are estimated. The control architecture and logic embedded in the EMS are discussed in detail.

Keywords: EMS, Peak power control, Cost saving, Peak shaving, Islanding mode.