Full feedforward of grid voltage for grid-connected inverter with LCL filter to suppress current distortion due to grid voltage harmonics

Xuehua Wang, Xinbo Ruan, Shangwei Liu, Chi Kong Tse

Research output: Journal article publicationJournal articleAcademic researchpeer-review

244 Citations (Scopus)

Abstract

The grid-connected inverter with an LCL filter has the ability of attenuating the high-frequency current harmonics. However, the current distortion caused by harmonics in the grid voltage is difficult to be eliminated. Increasing the loop gain can reduce the current distortion, but this approach is compromised by the system stability requirement. Without increasing the loop gain, applying feedforward of the grid voltage can suppress the effect of grid voltage harmonics. This paper proposes the feedforward function of the grid voltage for the grid-connected inverter with an LCL filter. Specifically, the proposed feedforward function involves proportional, derivative, and second derivative of the grid voltage, and can be simplified according to the dominant harmonics in the grid voltage. The proposed feedforward scheme can effectively suppress the current distortion arising from the grid voltage harmonics, and the steady-state error of the injected current can be substantially reduced even if a conventional proportional and integral regulator is applied. A 6-kW experimental prototype has been tested to verify the effectiveness of the proposed feedforward scheme.
Original languageEnglish
Article number5580125
Pages (from-to)3119-3127
Number of pages9
JournalIEEE Transactions on Power Electronics
Volume25
Issue number12
DOIs
Publication statusPublished - 1 Dec 2010

Keywords

  • Damping resonance
  • dual-loop control
  • feedforward
  • LCL filter
  • total harmonic distortions (THD)

ASJC Scopus subject areas

  • Electrical and Electronic Engineering

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