Combined DC and AC Integration of Energy Sources in Hybrid 3-Phase Off-Grid Systems

Abstract

Hybrid systems which incorporate more than one energy source face the challenge of integrating DC sources like PV and AC sources like wind turbines or diesel gensets at the same time. Currently, two main paradigms are pursued in order to supply off-grid AC loads: DC-coupled systems and AC-coupled systems. However, DC-coupled systems are normally not able to integrate AC sources like wind generators directly but via rectifiers. AC coupled systems have to invert the electricity generated by DC sources like PV and rectify them again to charge batteries. The result of these concepts is inefficient operation and high investment costs. Conergy ISA hybrid inverters are designed to integrate DC and AC sources in their natural way: direct integration of AC sources like in a grid and maximum efficiency with direct DC integration