Single stage inverter for a direct AC connection of a photovoltaic cell module

There are several possibilities to transfer the energy taken from a photovoltaic cell to the grid. In the past, several cell modules used the same centralized inverter to transfer the energy to the grid. Nowadays, decentralized modules are preferred because of their versatility to harvest a larger amount of power, even when some of the modules of the total surface are covered and do not receive the same solar irradiation. This paper presents an inverter topology that can be used to connect a photovoltaic cell module directly to the grid. The inverter is based on a single stage Flyback topology and it is quite simple. Furthermore, a maximum power point tracking algorithm is proposed. The system can be implemented in a very simple microcontroller and the output current, although it is not sinusoidal, its harmonic content is lower than the limit imposed by IEC 61000-3-2 regulations. A prototype of the topology has been built and tested.