Multiplexed electric vehicle charger provides affordable and flexible Level 2 charging

A system to affordably charge multiple electric vehicles (EVs) or plug-in hybrid electric vehicles (PHEVs) utilizing one or more Level 2 (L2) chargers is presented in this paper. This solution overcomes the issues associated with L2 charging such as high equipment and installation costs, underutilization of chargers and grid loading concerns. It is ideal for locations where L2 chargers may remain idle for extended periods such as employee parking lots, hotels and long-term parking facilities. The design uses commercially available L2 EV chargers, a low-cost programmable logic controller (PLC) and support hardware to provide a round-robin charging scheme for multiple EV/PHEV charging spaces. Additionally, the system provides various options including priority charging and smart grid functions like time-of-use charging and peak load control.