Soft-Switching Bidirectional Step-Up/Down Partial Power Converter With Reduced Components Stress

This article introduces a step-up/down series partial power converter (S-PPC) based on isolated current-source dc–dc converter topology. The proposed S-PPC exploits the most important feature of the used current-source topology, such as the capability to operate with both voltage polarities in the series port to decrease its rated power. Other advantages include soft switching in the entire operating range and low current stress of semiconductor components even at very low series voltage. In addition, the proposed S-PPC provides protection and soft-start capabilities due to the integration of a solid-state circuit breaker. The article explains the operation principle of the proposed S-PPC and compares it to the closest known competing S-PPC based on the dual active bridge topology. An experimental prototype rated for 3.5 kW with maximum processed power of 600 W was built to confirm the converter operation principle and its features. Its experimental efficiency reaches 99.3%. The proposed S-PPC also shows a good regulation capability at challenging operating points, like nearly zero series voltage.