Power-Electronics-Based Energy Management System with Storage

Abstract

This paper demonstrates the 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 user’s preference. The EMS 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 accomplishes peak power control by sup-plying battery power to the local loads while they are powered by the ac grid if the loads get large. The electricity cost savings accom-plished by peak shaving are estimated. The EMS functionality is demonstrated by experimental measurements on a laboratory pro-totype. The control architecture and logic embedded in the EMS are discussed in detail.