3kW Single-phase Non-insolated PV Grid Inverter Research And Design

As one of the optimal new energy sources，the solar energy has been applied more and morewidely by the human. And the grid-connected photovoltaic inverter is one of the necessaryequipment of the grid-connected photovoltaic system.The grid-connected photovoltaic inverter is an equipment which changes the DC from the solarcell to AC according with the public grid and transports to the public grid. According to differentstandard, the structure of the grid-connected photovoltaic inverter is divided to many kinds. Thisarticle introduces a kind of line frequency unisolated inverter.In this article the principle of design and the choice of the devices and preferences of theintelligent power module (IPM) board, the CPU board and the assistant power board are introducedin detail. It has introduced each MPPT control mode of the grid-connected inverter and have acomparison among them. TMS320F2808A of TI company is the micro-control chip of the system.The function and characteristic of the chip and the generating process of the whole system isintroduced in detail too, and the flow charts of the programs are list.Finally, it introduces the harm of the islanding and several kinds of familiar islanding detectionmethods.