Interleaved SEPIC PFC converter using coupled inductors in PEV battery charging applications

In ac/dc power factor correction (PFC) applications, where a wide range dc link voltage is required, boost derived topologies are no longer the most suitable circuit topologies for universal grids. In this paper, an interleaved SEPIC PFC converter, capable of providing a wide range dc link voltage, is investigated for onboard isolated battery chargers for plug-in electric vehicle (PEV) applications. The proposed converter is well adapted to achieve the maximum efficiency point tracking of the second stage LLC topology of an onboard isolated charger. Coupled inductors are utilized to reduce the component count and to bring the benefits of reduced input ripple current, lower switching losses, less total harmonic distortion (THD), and resistance to duty cycle mismatch. A 3.3 kW interleaved and coupled SEPIC converter, generating 200V-420V dc link voltages from the universal grid, is designed and simulated to verify the proof of concept.