Modular isolated DC-DC converter with multi-limb transformer for interfacing of renewable energy sources

This paper presents a modular isolated scalable three phase dual active bridge(DAB) DC-DC converter configuration using three multi limb high frequency transformers. The proposed converter has the advantage of having multiple low and high voltage dc links, which can be used at different power levels. The converter has three high voltage dc links which can be used for cascaded inverters or can be connected in series to provide a high dc link voltage for medium voltage grid-tie inverter. Multiple number of renewable energy sources(RES) can be connected to the low voltage side dc links to feed power to the grid. The paper work contains converter configuration, equivalent circuit of multi limb transformer, control of converter for a single renewable energy source and multiple renewable energy sources.