Multi-Objective Power Management for EV Fleet With MMC-Based Integration Into Smart Grid

Modular multilevel converter (MMC) is a possible solution for integrating an electric vehicle (EV) fleet into the smart grid. Considering the differences of initial state of charge (SOC) and the inherent randomness in charge/discharge demands from the various EVs connected to the MMC, it becomes challenging to control the MMC in order to satisfy the network and EV fleet requirements. This paper proposes a multi-objective power management strategy for a MMC-Based EV fleet to be integrated into the smart grid using a virtual SOC model and coordinated control of the power flow among the arms of the same and different phase-units by taking advantage of circulation current. The model of the MMC-based EV fleet system is developed in MATLAB/Simulink and simulation results show that the multi-objectives of differential charging/discharging power control and interactive power management between EVs and utility can be effectively realized, while the three-phase output power of MMC is kept in balance and circulation current is controlled, thus, mitigating the negative impact of large-scale application of EVs on the utility grid.