Steady-state analysis of a dual active bridge interface for offshore solar photovoltaic farms

Abstract

The integration of offshore renewable energy sources including solar photovoltaic (PV) systems and wind farms, necessitates reliable and efficient grid interfacing. High Voltage Direct Current (HVDC) systems based on voltage source converters (VSCs) are well-suited for this task due to their controllability and long-distance transmission capabilities. In such systems, modular sub-conversion stages are often employed to manage power from multiple PV arrays. This paper focuses on the Dual Active Bridge (DAB) topology as the DC-DC converter used in one submodule of the PV-side converter of a VSC-based HVDC system. The DAB converter is ideal for this purpose, as it offers high-efficiency and isolation. Steady-state analysis of the PV-DAB is presented, with the system modeled and simulated using PLECS standalone software. Control considerations such as cascaded voltage and current loops, along with maximum power point tracking (MPPT), are discussed in the context of submodule performance and integration.