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 2ω<inf xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0</inf> 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.