Abstract
In the field of electric vehicle charging, achieving fast charging at the current mainstream voltage levels of 800 V or 1000 V typically requires the use of a cascaded voltage-source converter to generate higher output voltages. However, traditional cascaded voltage-source converters often rely on two-stage independent control, making them vulnerable to voltage imbalances in the power grid. To address these challenges and simplify control while reducing current distortion and imbalance on the grid side, this paper proposes a coordinated control strategy for cascaded voltage-source converters. The proposed strategy unifies the control of both the front and rear stages, allowing for coordinated adjustment of the grid-side current and output voltage by leveraging the degrees of freedom of both stages. Notably, this approach eliminates the need to sample the DC link voltage, resulting in improved stability and balance in the grid-side current and output voltage. Simulations and experimental results demonstrate the effectiveness and superiority of the proposed control strategy.