A Hierarchical Optimization-Based OMPC Algorithm for Power Sharing in Multi-module Fast EV Charging Systems

Abstract

This article introduces a novel Optimal Modular Power Coordination (OMPC) algorithm for multimodule, multiport Fast Electric Vehicle Chargers (FEVCs). The proposed algorithm addresses the critical challenge of coordinated power distribution at both the module and charger levels through a hierarchical optimization framework. At the upper layer, a mixed-integer optimization model determines the optimal number of active power electronic modules (PEMs), selects the most efficient modules for contribution, and governs inter-port PEM borrowing decisions. At the lower layer, a real-time convex optimization routine computes optimal power-sharing ratios among the selected PEMs while satisfying grid limitations, module constraints, and thermal operating conditions. A key contribution is the introduction of PEM borrowing, a new concept that enables flexible reallocation of module power across different charging ports, significantly enhancing the charging power range and enabling dynamic split dual-port operation. Comprehensive simulation and experimental case studies validate the proposed OMPC algorithm, demonstrating substantial improvements in charging flexibility, module utilization balance, and charging speed reliability. Results confirm that the OMPC approach effectively mitigates charging bottlenecks and enhances the overall performance of multimodule FEVC systems.