Advantages of DC-Coupled EV Chargers to Benefit Next-Generation Clean Power Systems

Electric vehicle supply equipment (EVSE), more commonly known as electric vehicle (EV) chargers, are traditionally categorized by how they charge the EV ̶ either alternating current (AC) or direct current (DC). Regardless of whether charging is AC or DC, almost all are powered exclusively by AC. But EV chargers are ever more likely to be components of clean power ecosystems with DC-based devices, such as energy storage batteries, photovoltaic (PV) solar modules, hybrid PV string inverters and DC microgrids. In these types of power ecosystems, AC-coupled EV chargers (that is, those which are powered by AC) suffer significant disadvantages, including unnecessary conversion power losses and duplication of expensive converter power subsystems. This session explores the advantages of DC-coupled EVSEs (that is, those which are powered by DC), including higher EV charge rates, greater power efficiencies, lower system cost, bi-directional (V2G, V2H, V2L) charging benefits, and multi-source and hybrid-source input flexibility.