Coordinated charging of plug-in electric vehicles in unbalanced three-phase residential networks with smart three-phase charger

Abstract

The penetration levels of plug-in electric vehicles (PEVs) is expected to rapidly increase within the next few years due to global trend of energy saving and environmental protection. It is well-known that uncoordinated charging of PEVs in residential distribution feeders will have significant negative impacts on grid performances causing increased losses, poor voltage regulations, network congestion and overloading of distribution transformers. Furthermore, the forthcoming smart grids will be unbalanced due to non-uniform distributions of DGs such as rooftop PVs as well as PEVs in the three phases with unpredictable charging rates, times and durations. This paper explores the detrimental impacts of random PEV charging on the distribution transformer loading and bus voltage profiles of an unbalanced smart grid. A decentralized three-phase PEV charging strategy is introduced which is capable of switching vehicle charging between the three phases based on the network data provided by the smart meters. Simulation results will be generated and analyzed for an unbalanced three-phase 62 node residential network populated with PEV chargers using Matlab/Simulink software.