Research on the harmonicrestraint energy feedback based on LCLfilter

 

WANG Yan, ZHAO Kongcang, HE Huiyong, TANG Lijun,

ZHAO Dan, LIAO Wenping

(School of Physics and Electronic Sciences, Changsha University of Science & Technology, Changsha 410114, China)

 

Abstract: Aiming at the resonant peak in the current waveform which is caused by LCLfilter, a capacitor current feedback loop as the active damping was proposed to restrain it. The capacitor current loop and inverter side current loop make up the current double closedloop control strategy. However, the harmonics in output current was not restrain by carrent double loop control. Therefore, the compound control technology based on the repetitive controller and current double loop control was used to control the energy feedback system. And the compound control technology was studied and analyzed in the stability, disturbance suppression, convergence and steadystate error characteristics of the system. the simulation model of the threephase energy feedback system with LCLfilter was built based on Matlab/Simulink platform. The results indicate that the compound control technology is superior than the current doubleloop control through the comparison of harmonic analysis and the capacity of interference suppression.

Key words: LCLfilter; active inverter; active damping; repetitive control