Control And Research Of Single Phase Photovoltaic Inverter

With the development of Solar Photovoltaic cells and Power electronics technology, PV had become one of the new main-stream in the use of energy. Nowadays, PV has advanced toward low-cost,high efficiency and high-power direction, which the off-grid connected and grid-connected systems were mainly forms in the Solar photovoltaic power generation. Single-phase PV grid-connected inverter is used to convert DC into AC with same the frequency and phase. This paper focuses on single-phase small power grid-connected system. The grid-connected solar systems were researched in more comprehensive and much depth. The main contents are as follows:1.Single phase grid-connected inverter main circuit topology and operating principle were analyzed in detail. The DC capacitor, AC side inductor capacitor, main circuit IGBT and buffer circuit components parameters were calculated from the wave form simulation and experimental point of view for the single-phase grid-connected. The output voltage and current harmonics waveforms were less, at last, the basic current and voltage have in phase with the purpose of frequency.2. In order to prevent the same bridge arm through the power switch, we propose a method of setting the dead-time during the phase conversion of sinusoidal fundamental wave, and to compensate the dead-time with the current loop. Then we set the appropriate the dead-time to reduce the THD of the output waves by simulate the whole PV system.3.Since the output characteristics of PV cells have strong non-linear, and its output power has been influenced easily by the sunlight intensity,ambient temperature and other factors. The paper described the MPPT methods with a variable algorithm of PV. We also analyzes the causes and hazards of the network when the PV system occurred and the island effected, at last, it introduce both active-passive detection methods and prevention strategies.4.PV inverter by the voltage source controlled on the base of TMS320F2812DSP was analyzed from the experiment results, which has low distortion output waveform and the output PF close to 1, thus it increase the efficiency of PV inverter systems and to ensure its safe and reliable operation.Experimental results show that the circle structured light calibration method this thesis raised can complete the calibration quickly and efficiently, the calibration precision is high, and the expected goal has achieved.