Distributed cooperative charging for plug-in electric vehicles: A consensus+innovations approach

Abstract

Leveraging flexibility of charging schedules of Plugin Electric Vehicles (PEVs) charging schedules could reduce PEVs' charging cost and alleviate transportation electrification challenges. The rapid growth in the number of PEVs and their geographical spread hinder applicability of centralized approaches to coordinate charging schedules for a fleet of PEVs. In this regard, we propose a fully distributed solution for solving the PEVs' Cooperative Charging (PEV-CC) problem, i.e., minimizing cost of procuring electricity for a PEV fleet whilst accounting for each PEV's battery constraints and the charging infrastructure limitations. Our proposed method assigns communication and computation responsibilities to charging stations (agents) and obtains a distributed solution for the PEV-CC problem through an iterative collaboration between agents. The collaborative efforts of agents over the course of iterations result in solving the first order optimality conditions of the PEV-CC optimization problem. The structure of each agent's update functions ensures an agreement on a price signal while enforcing individual PEVs' constraints, hence, each iteration yields a feasible solution for the PEV-CC problem. Finally, we tested the performance of our proposed algorithm on a fleet of PEVs.