Versatile Controller Architecture for a Universal DC Fast Charging Front-End

Universal dc fast chargers, capable of operating from either single-phase (1ϕ) or three-phase (3ϕ) grids, require a configurable, high power density ac-dc front-end which not only involves a high degree of hardware re-utilization between 1ϕ and 3ϕ operation, but a corresponding level of control versatility as well. This work develops a general control architecture for a universal ac-dc front-end based on a three-leg topology, which can operate the system as a unity power factor corrector in both 3ϕ and 1ϕ configurations. A simple and effective control solution is employed in 1ϕ operation to re-utilize one of the system legs as an active power filter and remove the 2ω0 fluctuating power without needing dedicated harmonic suppression loops. The proposed control operation is validated through simulations and Hardware-in-the-Loop (HIL) testing for a 10kW/6.6kW design, with experimental results demonstrated for 1ϕ closed loop operation at reduced power.