Improved cascade-type repetitive control of grid-tied inverter with LCL filter

An improved cascade-type repetitive controller with forward channel gain is proposed for a grid-tied inverter with LCL filter to achieve fast transient response and very low total harmonic distortion. The choices of the RC parameters such as RC control gain k
_rc
, the phase compensator parameter m have been discussed. The simulation results show the improved cascade-type RC has fast dynamic response, high steady accuracy and good robustness.