Weighted Average Current Control in a Three-Phase Grid Inverter With an LCL Filter

Author

He, Ning ; Xu, Dehong ; Zhu, Ye ; Zhang, Jun ; Shen, Guoqiao ; Zhang, Yangfan ; Ma, Jie ; Liu, Changjin

Author_Institution

Inst. of Power Electron., Zhejiang Univ., Hangzhou, China

Volume

28

Issue

6

fYear

2013

fDate

Jun-13

Firstpage

2785

Lastpage

2797

Abstract

A novel control method, named weighted average current control (WACC), is proposed for damping control of a three-phase grid inverter with an LCL filter. In this method, the sum of partial inverter current and partial grid current is used as the feedback of the current control loop. By using WACC, three-phase current control of the grid inverter can be well decoupled under synchronous rotating frame. Furthermore, the system transfer function is reduced from the third-order system to the first-order system. Consequently, the control loop gain and bandwidth can be increased, which improve the rejection capability to the background grid voltage harmonics. The performance of the proposed control is also analyzed in case of filter inductance variation. Finally, the experiments are presented to validate the theoretical analysis.

Keywords

damping; electric current control; invertors; power filters; power grids; LCL filter; WACC; background grid voltage harmonics; control loop gain; current control loop; damping control; filter inductance variation; first-order system; partial grid current; partial inverter current; rejection capability; synchronous rotating frame; system transfer function; third-order system; three-phase grid inverter; weighted average current control; Bandwidth; Current control; Damping; Inverters; Pulse width modulation; Resonant frequency; Transfer functions; Grid inverter; LCL filter; three phase; weighted average current control (WACC);

fLanguage

English

Journal_Title

Power Electronics, IEEE Transactions on

Publisher

ieee

ISSN

0885-8993

Type

jour

DOI

10.1109/TPEL.2012.2219322

Filename

6304933