Phase Shifted Full Bridge DC-DC Converter for Photovoltaic MVDC Collection Network

Abstract

This article presents the application of a phase-shifted full bridge (PSFB) converter for medium voltage dc collection networks suited to photovoltaic power plants. The unidirectional structure of the converter is beneficial in terms of cost and simplicity of hardware implementation of the MV circuit components. The design of the PSFB converter is presented considering ratings of 250 kW power, 1.2 kV input and 20 kV output. A converter model and a novel input voltage control are developed and verified. A tuning method is given taking into account the effect of different transformer leakage inductance values. The behaviour of the PSFB under PV power production profile and MV network faults is studied in simulation and verified against a reduced-scale prototype with ratings of 30 kW and 350 V / 600 V operating at 20 kHz. The experimental verification of the control is performed considering a real PV power profile. The experimental results under faults show the same response as in simulations. The PSFB fault response is observed to be superior compared to other dc-dc topologies with capacitive output filter only.

Pierre Le Métayer, Quentin Loeuillet, François Wallart, Cyril Buttay, Drazen Dujic, Piotr Dworakowski

Published in IEEE Access