Optimal Energy Management of a Hybrid AC/DC Commercial Building Microgrid With Heterogeneous EV Charging Infrastructure
This paper presents the development of an energy management system (EMS) designed for a commercial building microgrid that integrates both AC and DC grids. The building infrastructure includes various electrical loads, photovoltaic (PV) panels, and a battery energy storage system. Additionally, the facility is equipped with seven electric vehicle (EV) chargers, including five AC chargers and two DC chargers, with one of the DC chargers supporting bidirectional power flow. The primary objective of the EMS is to minimize overall energy costs incurred from purchasing electricity in the day-ahead market by optimizing the operation of these components. Several use cases are developed and evaluated, including a reference case and comparisons with baseline charging and rule-based EMS strategies. Additional analyses examine deviations in PV, load, and electricity-price forecasts; variations in user behavior and satisfaction requirements; different peak-shaving limits and penalty factors; alternative system operating modes; and increased PV and battery storage capacities. The evaluation of these use cases provides a detailed analysis of their impact on energy costs, consumption, and operational efficiency. The findings confirm that the EMS effectively optimizes power flow under diverse operating conditions in a commercial building environment.