Integrating photovoltaic (PV) sources into a medium-voltage DC (MVDC) collection network requires a DC–DC converter with specialized grid-compatible characteristics. This paper explores the use of a Phase-Shifted Full-Bridge (PSFB) converter for MVDC collection networks in large-scale PV power plants. The converter’s unidirectional structure provides advantages in cost reduction and simplifies the hardware design of medium-voltage components. The PSFB converter is designed for a power rating of 250 kW, with a 1.2 kV input and a 20 kV output. A detailed converter model is developed along with a novel PSFB input-voltage control strategy for regulating the DC-link voltage. A tuning method is also proposed, accounting for variations in transformer leakage inductance. The converter’s performance is analysed under real PV generation profiles and medium-voltage network fault conditions through simulation. Validation is carried out using a reduced-scale prototype rated at 30 kW and 350 V/600 V, operating at 20 kHz. Experimental tests under realistic PV profiles and fault scenarios closely match the simulation results. The PSFB demonstrates superior fault response characteristics compared to other DC–DC converter topologies with capacitive output filters, making it a strong candidate for grid-connected MVDC applications.