Distributed Peer-to-Peer Coordination of Hierarchical Three-Phase Energy Transactions among Electric Vehicle Charging Stations in Constrained Power Distribution and Urban Transportation Networks

The electrical vehicle charging station (EVCS) paradigm will become more proactive progressively owing to the massive deployment of on-site distributed renewable energy (DRE) and battery energy storage systems (BESS). In this environment, the coordination of peer-to-peer (P2P) transactive energy (TE) trading among EVCSs would be a critical topic that would demand further investigation. This article proposes a hierarchical framework for the optimal P2P trading among EVCSs in constrained urban transportation networks (UTNs) and power distribution networks (PDNs). The UTN operation is incorporated through a multiperiod traffic flow assignment problem (MTAP), which is solved by the transportation system operator (TSO). After receiving the corresponding EV assignments, a P2P trading approach is considered among EVCSs, which would emphasize EVCS privacy while minimizing the TE trading cost. The trading results are subsequently delivered by EVCSs to the distribution system operator (DSO), which would solve a three-phase unbalanced optimal power flow to guarantee the secure PDN operation. If any PDN constraints are violated, a trading adjustment signal will be returned to each EVCS in an iterative process. Numerical experiments based on EVCSs located on a 12-node UTN and the modified IEEE 33-bus PDN validate the effectiveness of the hierarchical P2P coordination approach and solution methodology, where the total operation cost of EVCSS is reduced by 16.61%.