Research on Active Damping Control Strategy of Three Phase Grid-connected Inverter
LCL filter has the advantages of low cost,high harmonic attenuation ability,so it is suitable for high-power three-phase grid-connected inverter.Nowadays,LCL filter is widely used in all kinds of new energy power generation.LCL filter has resonance problem,which leads to system stability reduction of three-phase grid-connected inverter.In this paper,the influence of LCL filter on the system is analyzed by establishing the transfer function of LCL filter.And by applying the capacitor current feedback,the virtual impedance of system is increased.Hence,by this active damping control strategy can increase the damping of the system,which can suppress the resonance peak of LCL filter,and improve the stability of the system.Finally,a simulation model is built in Matlab/simulink to veri-fy the feasibility of the algorithm.The simulation results show that the active damping method can increase the sta-bility of the system without increasing the loss of the system,and the output harmonic content of the grid-connected current of the three-phase grid-connected inverter is low.
three phase grid-connected inverteractive damping control strategyLCL filter