Local automatic load control for electric vehicle smart charging systems extensible via OCPP using compact submeters

There are many challenges in implementing grid aware electric vehicle charging systems with local load control. New opportunities for innovative load control were created as a result of changes to the National Electric Code (NEC) for automatic load control definitions for EV charging infrastructure. Stakeholders in optimised dispatch of EV charging assets include the end users (EV drivers), site owner/operators, facility managers and utilities. NEC definition changes allow for `over subscription' of more EV charging stations than can be continuously supported if the total load at any time is within the supply system safey limit. Local load control can be implemented via compact submeter(s) with locally hosted control algorithms with direct communication to the managed EVSEs. Larger groups of EVSEs can be managed as a constrained system via network connections, or meshes of smaller nodes, with cloud based control algorithms coordinating local control nodes. This paper is constrained to only AC charging, from grid to vehicle, in a modestly sized system, extensible to larger meshes of EV charging stations.