Abstract：This paper focusses on the problem of direct current injection caused by voltage-controlled inverter connection. Based on the axial-voltage regulation single phase LCL inverter, the mathematical model of grid connected inverter has been built. This paper shows the details of mathematical analysis and formula derivation by analyzing the reasons of DC component indection. The result shows that the DC component has a nearly linear relationship with the voltage amplitude and frequency. Thus, this paper proposes the current deviation compensation (CDC) control strategy to diminish and eliminate the impacts of DC component. This strategy can compensate the injection direct current when the grid voltage and frequency fluctuation happen. The CDC control can also improve the performance of voltage-controlled inverter at the same time. Finally, simulation and experiment verify the effectiveness of the proposed control strategy.
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2017, Vol. 32 
