.3 Kw Photovoltaic Grid-connected Inverter Developed

As one of the optimal new energy sources ,the solar energy has been applied more and more widely by the human.And the grid-connected photovoltaic inverter is one of the necessary equipment of the grid-connected photovoltaic system.The grid-connected photovoltaic inverter is a equipment which changes the DC from the solar cell to AC according with the public grid and transports to the public grid . According to different standard, the structure of the grid-connected photovoltaic inverter is divided to many kinds.This article introduces a kind of line frequency isolated inverter.In this article , the principle of design and the choice of the devices and preferences of the IPM board,the CPU board and the assistant power board are introduced in detail.It has introduced each control mode of the grid-connected inverter and have a comparison among them. TMS320LF2407A of TI company is the most control chip of the system. The function and characteristic of the chip and the generating process of the SPWM is introduced in detail too ,and the flow chart of the programs are list.Finally , it introduces the harm of the islanding and several kinds of familiar islanding detection methods.