A network-secure two-stage framework for hierarchical energy management of EVs, charging stations, and distribution network

Emerging electric vehicles (EVs) and charging stations (CSs) with renewables and energy storage systems (ESSs) promote the diversity of market participants. However, they also increase the difficulty in energy management and even pose threats to the secure operation of distribution networks. To address the issues, this paper presents a two-stage hierarchical energy management method. In the first stage, a hierarchical distributionally robust optimization (DRO) model is developed for the interaction between EVs, CSs and distribution system operator (DSO). By leveraging dual transformation, KKT conditions, McCormick relaxation and the big-M method, this nonlinear model is transformed into mixed integer linear programming (MILP), which can be directly solved by commercial solvers. Then, based on transactive results in the first stage, several active network management (ANM) techiques, such as network reconfiguration and demand-side resources (DRs) management are adopted by DSO in the second stage to ensure network security without sacrificing different entites' payoffs. In case studies, comparing to traditional centralized market managed by DSO, the proposed hierarchical interaction mechanism with trade-off objectives can increase total social welfare by 10%. Meanwhile, each market participant's payoffs can rise >3% with ANM techiques.