Asymmetrical Half-Bridge Converter with Input Current Ripple Reduction

Employing an L-C-L filter cell to modify the asymmetrical half-bridge converter (AHBC), an AHBC with input current ripple reduction (AHBC-CRR) is proposed. In addition to having zero-voltage switching operation, low voltage stress, lossless snubbing, and voltage clamping features preserved from its predecessor, the proposed converter can shape input current waveform of AHBC to a non-pulsating fashion. Consequently, the ripple and undesired harmonic components of the input current can be significantly reduced without adding a large input filter. These characteristics make it suitable for high-input voltage high-frequency high-efficiency and low electromagnetic interference (EMI) power conversion applications. Besides the circuit analysis and design consideration, two 100-kHz converters, AHBC and AHBC-CRR, with the same specification, 300-400-V input, 24-V/10-A output, are built and tested. Several performance comparisons are made to demonstrate the superiority of the proposed converter over AHBC.