A Grid-connected Inverter, The Harmonic Suppression

To achieve the aim of feedback of energy and harmonic control simultaneously, here, we report a new design of line-connected inverter with DSP on the basis of the research on line-connected technology of distributed generation system.First, we introduced the basic structure of line-connected inverter and the fundamental knowledge of harmonic. Meanwhile, three-phase voltage-bridge inverter grid model and the common inverter control technology were analyzed in detail, the relevant conclusions we educed from which provide the basis and foundation for the design of line-connected inverter.Secondly, we made a detailed statement of the harmonic detection method, and the methods to achieve harmonic control were deduced from the theoretical analysis. The harmonic detection logic of instantaneous reactive power theory was emphasized. And we also discussed how to achieve such DSP harmonic detection method.Finally, we analyzed the design of the main circuit, driving circuit, the sampling circuit, digital signal processing circuit etc, software design and process was introduced too. The control strategies of circuit and the implementation of the control strategy were discussed, and what is more, a prototype was designed to prove some conclusions in the paper, the correlative experimental waveforms were given also.