On-line Decentralized Charging of Plug-In Electric Vehicles in Power Systems

Plug-in electric vehicles (PEV) are gaining increasing popularity in recent years, due to the growing societal awareness of reducing greenhouse gas (GHG) emissions and the dependence on foreign oil or petroleum. Large-scale implementation of PEVs in the power system currently faces many challenges. One particular concern is that the PEV charging can potentially cause significant impact on the existing power distribution system, due to the increase in peak load. As such, this work tries to mitigate the PEV charging impact by proposing a decentralized smart PEV charging algorithm to minimize the distribution system load variance, so that a ‘flat’ total load profile can be obtained. The charging algorithm is on-line, in that it controls the PEV charging processes in each time slot based entirely on the current power system state. Thus, compared to other forecast based smart charging approaches in the literature, the charging algorithm is robust against various uncertainties in the power system, such as random PEV driving patterns and the output of distributed generators (DG).