Research On Photovoltaic Grid-Connected Inverter Based On DSP

Since the Industrial Revolution, the traditional fossil fuels represented by coal, oil andnatural gas has been had the large-scale use, which has promoted the development of humansociety greatly, and the productivity of human society has reached a new stage. However,the traditional fossil fuels are not inexhaustible. With the gradual depletion of fossil energy,mankind began looking for the alternative energy sources. In recent years, the solar energy asa renewable green energy more and more wins the favor of mankind, which is renewable andpollution-free. Photovoltaic power generation is a form of solar power in the mostrepresentative. Among which photovoltaic power generation is an important direction forutilization of solar energy, and has broad prospects.This paper focused on the topology and control method of household roof photovoltaicgrid-connected inverter with Low power. The design used two classes structure withouttransformer or isolation, including the former DC-DC converter and the after DC-ACinverter. The former DC-DC converter uses a boost chopper circuit that plays the role of theboost and achieves maximum power point tracking control in PV systems to improve theutilization efficiency of photovoltaic systems. The after DC-AC inverter uses voltage single-phase full-bridge inverter circuit as the main circuit topology, connected with the former DC-DC converter through the DC bus, direct current on DC bus is inverted to alternating currentand output grid current that has same frequency and phase with grid voltage and its Powerfactor is one.This paper used the fuzzy control method to control the output of the photovoltaic cellsand achieve maximum power point tracking. The after inverter controlled the output currentof inverter using SPWM. The system used a DSP chip as the main chip, which made the gridcurrent output of the inverter to be able to track the grid voltage. On the basis of theoreticalanalysis, the paper has built a MATLAB simulation model for the maximum power pointtracking control and Grid-connected current control. The simulation results demonstrate thefeasibility of the control scheme. On this basis, analyzed and designed voltage and currentdetection circuit, the IGBT drive circuit, the fault detection circuit, network synchronizationcircuit and so on. And analyzed the software design of DSP-based system, it can provide areference for the design of single-phase grid-connected inverter.