High-frequency full-bridge isolated DC–DC converter for fuel cell power generation systems

The paper presents high-frequency isolated soft-switching DC–DC converter for generating regulated high output voltage from fuel cell power modules using secondary-side phase-shift control to eliminate idling and circulating currents. The converter topology incorporates high-frequency center tap transformer with secondary-side phase-shift soft-switching control. Parasitic capacitors of the switching devices and the transformer leakage inductance are utilized to achieve zero-voltage switching (ZVS) in the primary side of the high-frequency transformer. Therefore, no extra resonant components are required for ZVS in the proposed converter. The inherent soft-switching capability allows high power density, efficient power conversion, and compact packaging. A prototype rated at 6.5 kW is proposed and simulated in PSIM software for validation purposes. The outcomes are very encouraging and confirm the wide range voltage control and soft-switching operation of proposed phase-shift converter.