Research and development of photovoltaic grid-connected inverter based on DSP

In this paper, photovoltaic (PV) grid-connected inverter which is the core device in PV grid-connected system has been in depth research. The current tracking control method is used in the inverter. In structure, this inverter consists of a DC/AC inverter and several connectors for switching and protection. A full bridge structure with the power frequency transformer has been applied in the DC/AC inverter. The prototype with 100W power based on DSP is developed for verifying the grid-connected control methods. Because of the powerful real time processing ability of the DSP, the output power factor of the PV inverter connected with grid can be controlled to unity. This prototype can realize grid-connect control and island protection function, and in addition the experiment results verify the feasibility of the design.