Pseudo Partial Power Processing Multilevel Modular High Gain Switched Tank Converter for Data Center Intermediate Bus Converter

In this paper, a pseudo partial power processing (P-PPP) multilevel modular high step-down gain switched tank converter (HGSTC) is proposed for data center application. The proposed HGSTC comprises high step-down gain multilevel modules, a low-voltage-side rectifier, and a non-isolated auto-transformer, of which the auto-transformer is the key to realize the P-PPP structure. Compared with full power conversion, the topology reduces the processing power by 12.5%. A detailed operation principle analysis of the converter is conducted, including derivation of voltage gain and soft-switching analysis. Furthermore, systematic configuration methods for the topology family are established, along with generalized expressions for voltage gain. The comparison with existing topologies reveals the advantages of the proposed converter. A 6mm-high planar auto-transformer design and optimization methodology is presented for ultra-thin intermediate bus converters in data center application. A 1 MHz 46–50 V input 5.75–6.25 V / 84 A output prototype is built for verification. The peak efficiency of the proposed converter reaches 96.03%, and the power density reaches 816 W / in³.