Modeling and Control of a Three-Phase Interleaved Buck Converter as a Battery Charger

This paper proposes a control design methodology for implementing a three-phase interleaved buck converter as a battery charger for electric vehicles (EVs). The control strategy utilizes a multi-loop cascade controller to implement the constant-current/constant-voltage (CC-CV) charging protocol, enabling fast and efficient battery charging. To address the inherent imbalance in current distribution among the converter phases, the inner control loop employs the democratic current sharing technique. The two outer loops form a seamless controller that facilitates a smooth transition from constant-current (CC) mode to constant-voltage (CV) mode. The controllers are designed using the root locus method in conjunction with conventional cascade control design principles. The proposed methodology is validated through numerical simulations of the switched system model implemented in MATLAB. Simulation results demonstrate robust performance in the presence of input voltage fluctuations, load variations, component failures, and parametric uncertainties.

Keywords: Battery charger, interleaved buck converter, cascade control, fast charging.