Two-phase operation for coordinated charging of electric vehicles in a market environment: From electric vehicle aggregators' perspective

The increasing penetration of electric vehicles (EVs) poses challenges to the operation of existing power systems owing to the spatial and temporal randomness and dynamics of EV charging. Although substantial theoretical research efforts have been made for EV coordinated charging management, the implementation and validation in the context of a practical market mechanism in the presence of EV aggregators require further exploitation. This study develops a two-phase coordinated charging scheduling solution in the energy market environment to optimally schedule EV charging loads for profit maximization from the perspective of EV aggregators. In the first phase, EV aggregators bid for energy in the day-ahead markets, considering a wide variety of uncertainties from EV charging and electricity markets. In the second phase, EV aggregators manage the charging loads of EVs in real time using purchased energy. The proposed solution was implemented and assessed using the Guangdong energy market as a case study through extensive simulation experiments. The numerical results confirm that the proposed method can enable the actual consumed energy from EVs to match the day-ahead bidding energy well. In this regard, the charging demand of EVs can be met with proper planning, to fulfill the coordinated charging operation of EVs in power grids.