Research on low-power and high-frequency photovoltaic grid-connected inverter

摘要

To improve the efficiency of photovoltaic grid-connected system, photovoltaic grid-connected inverter has been designed based on two stages of topology structure. High-frequency and push-pull forward converter is adopted in the front stage and single-phase full-bridge inverter is linked secondarily. Firstly, the working principles of push-pull forward converter and the photovoltaic inverter are analyzed in this paper. Then, the simulation model of system is established under the environment of MATLAB. The part of DC/DC and DC/AC are controlled respectively. The relevant algorithms of fixed voltage tracking control and current tracking control are verified. Especially, a single-polar bilateral control is used in DC/AC part, so reduced the loss of power devices, thus providing a good theoretical guidance for the system's realization.