A New Control Strategy Based on Capacitor Current Feedback Source Damping for LCL Three-Phase Public Electric Network Inverter

LCL filter has the characteristics of good filter performance, small total inductance and small size. It has been widely used in three-phase public electric network inverters. It is a third-order multivariable component system. Because the high freedom of control, there is resonance problem. In view of the above problem, this paper proposes a new control strategy that is based on the given public electric network side current, connected the inverter side current to public electric network and used the capacitor current feedback source damping control. This method combines the advantages of two current close loop control. The unit power operation is realized by feedback the capacitor current to the input of the current inner loop. The inverter side current close loop control is used to enhance system stability. Source damping is used to suppress resonance of LCL filter. Simulation results show the effectiveness of the proposed new control strategy.