Compensation of DC link oscillation in single-phase VSI and CSI converters for photovoltaic grid connection

In this work it is presented a technique to reduce DC link oscillation in Voltage Source Inverter (VSI) or Current Source Inverter (CSI) that operates connected to a single phase grid. That oscillation can be responsible for losses or malfunctioning of the DC sources (photovoltaic panels or batteries). It is also may cause efficiency reduction of photovoltaic generators. The oscillation reduction can be achieved by adding two power switches and a passive energy storage element to the converter topology. Details about design and control strategies for both topologies, which has demonstrated performance improvements, when compared with others solutions, are presented. Simulation and experimental results are provided to validate the theoretical approach and to evaluate the topologies performance and quantify energy efficiency gain.