Abstract：Three-phase grid-connected voltage source inverter(VSI) is often used to feed high quality current into grid in photovoltaic(PV) power generation system. But many factors, such as switching dead-time effects and disturbance of grids etc, will deteriorate the current waveform, and a large number of harmonic will be fed into grid too. Owing to the conflict between stability and fast response, proportional-integral (PI) controller has limited capabilities to restrain harmonic disturbances and can not guarantee the output performance of grid-connected inverter, so a new control algorithm using compound controller constituted by repetitive controller(RC) and PI controller is proposed in this paper to overcome the shortcomings of PI controller in harmonic control. A dynamic model of grid-connected inverter in synchronous rotating frame(SRF) is derived and the compound current controller design is presented too. Theoretic analysis and experimental results on a 20kW prototype verify that the proposed current controller offers a high performance of current control.
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2010, Vol. 25 
