A New Charging Scheme Based on Mobile Charging Robots Cluster: A Three-Level Coordinated Perspective

The rapid development of electric vehicles (EVs) brings great challenges to the charging infrastructure construction and the smooth operation of power systems, which facilitates emerging of a new charging scheme based on mobile charging robots (MCRs) cluster. In this article, a novel framework with three-level optimization and control on multiple time scales is proposed, and the interactions among the MCR operator, power systems and EVs are realized by means of the cloud-edge-terminal coordination-based architecture. In the first level, the operation dispatch scheduling of the MCRs is formulated as a multiobjective optimization problem considering the voltage security of power grids, which improves the charging service efficiency of MCRs on a slow time scale. In the second level, a new solution algorithm based on the proposed resource competition and occupation model is used to handle the charging decision for the MCR operator, which greatly reduces the calculation time and ensures the solution accuracy simultaneously. In the third level, a local coordinated control is proposed to enable cooperation among the MCRs on a fast time scale, which provides charging services for EVs within the optimization interval of the second level and achieves the fairness of the residual state of charge of the MCRs. Finally, simulation results validate the effectiveness and superiority of the proposed three-level coordination with comparisons of existing methods.