Study On Some Technical Problems Of Grid Connected Inverter Devices Of Photovoltaic Power System

The fossil energy is limited on contradictory global non-renewable storage capacity. With the development of human society, unlimited energy demand increasingly fierce, this conflict will lead to a global economic slowdown and imbalances. In such a world energy situation in the background, the use of new energy sources has become an effective way to resolve this contradiction.Solar energy as a form of new energy sources, the development and use by the world's attention, so the research of new energy generation systems and related technologies related equipment is necessary, and inverter device is a grid system and the interface between the grid and the network control system is directly related to the stability of the method. The suitable and effective grid control method can improve the stability of the solar photovoltaic power system, and the technology of the photovoltaic grid connected inverter is studied.First, we study the topology of the network and systems targeted for grid-connected inverter circuit, DC boost circuit analysis system, to develop the overall system design. Then the key technologies islanding detection technology, photovoltaic maximum power point tracking method and inverter grid control for a more detailed elaboration.Secondly, according to the sinusoidal pulse width modulation(SPWM) technology is one of the key technologies to control, the paper improved the original sampling method, using reverse-phase carrier intersection Sampling method, the modulation effect close to natural sampling rather than asymmetric regular sampling France, SPWM wave generated by the modulation method is closer to the sine wave, less harmonic content, and because each half cycle of the carrier once the switch-off time to update retains asymmetric regular sampling method to control the characteristics of real-time high, calculated for rapidly changing the output voltage needs of the occasion, the control point time that just solves a simple straight line equation of the intersection, the control algorithm is simple, saving the storage space of the microprocessor, is easy to implement in the DSP system. Experiments showed that the method is effective and feasible to compare the experimental results with asymmetric regular sampling method showed the intersection of style inverted carrier waveform sampling methodis superior to the asymmetric regular sampling method.Finally, for the case of photovoltaic power generation, and its related network device hardware design, including a boost Boost circuit parameters, the inverter circuit drive circuit and sampling circuit.