Research on droop control based on comprehensive compensation improvement
WU Fuzhuan
YIN Qingsen
ZHU Yongsheng
ZHANG Yiming
LIANG Mingxin
Abstract：For grid-connected inverters adopting droop control in low-voltage microgrids,due to the effects of the droop control characteristics and the virtual inductors,when the grid frequency decreases,the power factor of the system output will drop and the inrush current will be relatively large.To address this issue,the reasons for the fluctuation of reactive power output with the changes of grid frequency are firstly explained through theoretical analysis.An improved droop strategy based on comprehensive compensation is proposed.The improved droop control can dynamically adjust the amplitude and phase of the output voltage of the inverter,which not only improves the power factor of the system output but also further reduces the impact current when the grid frequency drops.Then,the stability of the improved droop control based on comprehensive compensation is analyzed by establishing the small-signal model of the grid-connected inverter.Finally,through simulation and experimental analysis,it is verified that the proposed improved droop control based on comprehensive compensation can effectively suppress the increase of output impulse current and the decrease of power factor when the grid frequency fluctuates,further improving the efficiency of the system and reducing the system loss.When droop control is used in low-voltage microgrids,due to the droop control characteristics and virtual inductance,when the grid-connected inverter decreases in the grid frequency,the power factor of the system output is reduced and the inrush current is large.In order to solve this problem,firstly,the reason for the fluctuation of the reactive power output of the system with the change of grid frequency is expounded through theoretical analysis,and an improved comprehensive compensation droop control strategy is proposed,which can dynamically adjust the amplitude and phase of the output voltage of the inverter,and further reduce the inrush current of the system when the grid frequency decreases while increasing the output power factor of the system.The stability analysis was carried out by establishing a small signal model of the grid-connected inverter.Finally,through simulation and experimental analysis,it is verified that the proposed improved droop control can effectively suppress the problem of increasing the output impulse current and decreasing the power factor when the frequency fluctuation of the grid frequency occurs.
Keywords：grid-connected inverterdroop controlvoltage dropspower factorsmall signal analysis
Publication Date：2025-10-25
Online Publishing Date：2025-11-24(First online date of this platform, not the publication date of the document)
Pages：10( 21-30 )