Performance evaluation of a grid-connected three-phase six-switch boost-type current source PV inverter under different switching strategies

Recently, boost-type current source inverters (CSIs) have received a considerable attention in grid connected photovoltaic (PV) applications thanks to their salient features such as high reliability and the aptitude to operate with a DC-link voltage lower than the grid side voltage. This paper investigates the performance of three different switching strategies for grid-connected six-switch boost-type CSI employed in a solar power conversion system. These strategies are analyzed in terms of the global average conduction and switching power losses, DC-link current ripple, and AC power quality. The proposed evaluation is based on experimental investigations of the power devices behavior and computer co-simulations. The obtained numerical and experimental results prove that the switching strategy with a freewheeling state placed in the middle of the overall pulse-period is the most appropriate in terms of efficiency and power quality.