Phases-controlled coordinated charging method for electric vehicles

When private electric vehicles (EVs), which will be the main part of the EVs' cluster in the future, are plugged in power system by single phase power line, can result to three-phase unbalance problem of distribution network. In this work, a phased-controlled coordinated charging method was put forward to solve this problem. Firstly, the impacts of charging load to distribution network was analyzed based on the equivalent circuit; and then an architecture of the control method and its corresponding optimal control model were introduced. The optimal model is a multi-objective optimization model, which includes minimizing load variance of each phase and minimizing the power asymmetrical degree of three-phase load; lastly, three scenarios considering balance and unbalance cases were envisioned to verify the reasonableness of this control method based on IEEE-37 distribution network. Results show that the phased-controlled coordinated charging method can minimize the load variance as well as the negative sequence current.