A digitally controlled double stage soft-switching converter for grid-connected photovoltaic applications

A photovoltaic generator exhibits nonlinear voltage-current characteristics and its maximum power point varies with solar radiation and temperature. In order to suitably connect the photovoltaic generator with the grid, single or multi-stage inverters are used addressing many specifications as high efficiency and large input voltage range. In the paper, the design, realization and performance evaluation of a single-phase 3 kW DC/AC power converter, using an active bridge DC/DC converter and a full bridge DC/AC is introduced, presenting a novel solution on the industrial scenario for the considered application. The control algorithms, including the maximum power point tracking, paralleling to the grid, and converter switching signals are digitally implemented on a standard microcontroller.