Partial Power Processing Based Two-Stage Half-Bridge Resonant Converter With Reduced Component Count

Partial power processing is an attractive solution that processes only a portion of the total power, which has the advantage of increasing efficiency. It can maintain high efficiency over a wide input range when combined with two stages. Since the conventional two-stage partial power processing structure adopts a full-bridge topology or multiple transformers to achieve smooth integration with a DC regulator, it results in a relatively high partial power processing ratio or a large number of circuit components, which limits the achievable efficiency. To deal with this issue, this article proposes a half-bridge-based partial power processing two-stage resonant converter combined with a buck-boost regulator. The integration of a parallel resonant converter and a buck-boost regulator within a half-bridge topology enables high conversion efficiency and a wide input voltage range while minimizing component complexity. This structure also enables a low partial power processing ratio while achieving a high step-up suitable for the target application. The theoretical analysis presented in this article highlights that the choice of DC regulator and the partial power processing ratio are critical factors in the design of a two-stage partial power processing converter. To experimentally validate the proposed converter, a 200W prototype was developed, operating at a switching frequency of 100kHz. The prototype was tested to confirm the functional feasibility and evaluate the performance of the proposed design.