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.
关键词
电网电压前馈/并网变流器/弱电网/稳定性/超前因子
Key words
grid voltage feedforward/grid-connected converter/weak grid/stability/leading factor
维普
万方数据