The Research Of PV Grid-connected Based On Flyback Micro-inverter

In recent years, caused by environmental pollution and energy demand tension, solar energy as one of the cleanest energy has become an ideal choice for the development of new energy sources. In the photovoltaic roof plan and building integrated photovoltaic power generation system, the low power micro-inverter has become more widely used. Micro-inverter is attracted the attention of researchers, while the development of inverters tends to high frequency, module integration and digitization. Therefore, research on the micro-inverter has a very high practical value. The design of the interleaved flyback micro-inverter is explained in this paper. Then the MPPT, power decoupling technology and gird-connected control strategy are studied deeply.First of all, the photovoltaic grid-connected inverter development background, status quo, and the structure of the photovoltaic power generation systems are introduced in this paper. The ingle ended and interleaved flyback inverter circuit structure, working principle and control strategy are analyzed in detail.Secondly, the common several kinds of maximum power tracking method are briefly introduced. The adaptive variable step size algorithm is proposed based on disturbance observation algorithm. It can improve the dynamic response speed and precision of the track. In addition, the power decoupling technology is introduced. The PV input side of the ripple and the secondary power grid disturbances are reduced when the power decoupling circuit has been introduced in staggered flyback inverter.Thirdly, the hardware and software of the interleaved parallel flyback inverter are designed. The flyback transformer of main circuit, sampling circuit, and signal processing circuit are designed and the master control chip, switch tube, rectifier diodes and other components are selected. The parameters of each part of the design are calculated in detail.Finally, the micro-photovoltaic (PV) grid power generation system is established, and the whole system is on-line debugged. The waveforms which are tested by oscilloscope show the quality of the waveform is good.Therefore, the purpose of the grid could realize.