Plug-in Electric Vehicle Charging Coordination Considering Distribution Protection System

Plug-in Electric vehicles (PEVs) imposed an extra-large electricity demand in distribution system. The high penetration of PEV charging could significantly stress the distribution system and causes severe voltage fluctuations, excessive power loss, line current and system overloading. Typically, in distribution system, the overcurrent relay is set 25% higher than the nominal current. Without proper control of PEV charging, the nominal current could be higher than nominal current. This will cause tripping of overcurrent relay and interrupted the charging of PEV. This paper proposes real-time multi-objective PEV charging coordination considering protective device constraints with aim to prevent power interruption which might be due to protection system failure.