Leading Factor Based Grid Voltage Feedforward Strategy for Grid-connected Converter
Grid voltage feedforward(GVF)is widely adopted in grid-connected converter control.However,the instability oscillation may be induced by GVF in a weak grid.To this end,the trend of the converters'stability changing with grid impedance when using traditional GVF is analyzed,and a leading factor-based grid voltage feedforward(LFB-GVF)strategy is proposed for the small stability region of the converter under the weak grid.In addition,the relationship between the leading factor and the maximum equivalent grid inductance that is adaptable for the converter is also analyzed.The analysis shows that compared with the traditional GVF,LFB-GVF can significantly improve grid-connected converter's stability region under the weak grid with an appropriate leading factor.Finally,the simulation and experimental results of two feedforward methods with the different grid impedances are given separately,and the results are consistent with the theoretical analysis.
grid voltage feedforwardgrid-connected converterweak gridstabilityleading factor