Dual Active Half Bridge Converter with Integrated Active Power Decoupling for On-Board EV Charger

Two-stage architecture is widely used in single-phase on-board chargers (OBCs) due to its intuitive design and simple control. To buffer second harmonic ripple power drawn from grid, Active Power Decoupling (APD) circuits with high reliability are preferred over conventional Aluminium Electrolytic Capacitor (AEC). However, APD circuits require additional power devices, which increase cost. To address this challenge, this work integrates APD in primary side of dual active half-bridge converter. The proposed circuit buffers second harmonic ripple power without using any additional power semiconductor devices. Detailed analysis and parameter selection for the proposed topology is included in this paper. The increase in current stress of transformer and power semiconductor devices due to circuit integration is limited to acceptable values by optimal selection of design parameters. Further, a control technique is suggested to buffer the second harmonic ripple power and transfer average power to battery. The transient and steady-state performance of the proposed 3.3 kW OBC to charge 72V battery pack is validated by circuit simulation studies in PLECS/Blockset.