System and method for managing vehicle charging stations

Abstract

A system and method for managing vehicle charging stations such that when at least two of a plurality of electric vehicle charging stations (also known as electric vehicle service equipment, or EVSE) occupied with vehicles awaiting a charge, the present system manages the charging of individual vehicles in cases where the aggregated demand for charging exceeds the capacity of the circuits supplying the plurality of EVSE. By cycling so that only a few of the vehicles are charging at a time, the demand on the circuits is kept below a predetermined limit. In cases where a load shedding event is in progress, the limit can be further reduced. In cases where the cost of electricity is varying dynamically, the system considers a driver's explicit charging requirements (if any) and preferences for opportunistic charging when the price of electricity is not too high.

We claim: 
     
         1 . A system for fairly managing a bank of EVSEs comprising:
 a controller, the controller having control over a plurality of EVSEs, the controller having a queue of requests for charging corresponding to at least some of the EVSEs in the bank, the controller selecting from among the requests in the queue and enabling corresponding EVSEs such that aggregate power draw of enabled EVSEs does not exceed a first predetermined limit, the controller subsequently disabling the corresponding EVSEs and returning requests relating to the corresponding EVSEs to the queue.