A robust control scheme for grid-connected voltage-source inverters

Shuitao Yang, Qin Lei, Fang Z. Peng, Zhaoming Qian

Research output: Contribution to journalArticlepeer-review

297 Scopus citations

Abstract

This paper analyzes the stability problem of the grid-connected voltage-source inverter (VSI) with $LC$ filters, which demonstrates that the possible grid-impedance variations have a significant influence on the system stability when conventional proportional-integrator (PI) controller is used for grid current control. As the grid inductive impedance increases, the low-frequency gain and bandwidth of the PI controller have to be decreased to keep the system stable, thus degrading the tracking performance and disturbance rejection capability. To deal with this stability problem, an H controller with explicit robustness in terms of grid-impedance variations is proposed to incorporate the desired tracking performance and the stability margin. By properly selecting the weighting functions, the synthesized H controller exhibits high gains at the vicinity of the line frequency, similar to the traditional proportional-resonant controller; meanwhile, it has enough high-frequency attenuation to keep the control loop stable. An inner inverter-output-current loop with high bandwidth is also designed to get better disturbance rejection capability. The selection of weighting functions, inner inverter-output-current loop design, and system disturbance rejection capability are discussed in detail in this paper. Both simulation and experimental results of the proposed H controller as well as the conventional PI controller are given and compared, which validates the performance of the proposed control scheme.

Original languageEnglish (US)
Article number5437252
Pages (from-to)202-212
Number of pages11
JournalIEEE Transactions on Industrial Electronics
Volume58
Issue number1
DOIs
StatePublished - Jan 1 2011
Externally publishedYes

Keywords

  • Current control
  • distributed generation (DG)
  • grid impedance
  • proportional-resonant (PR) controller
  • robust control
  • voltage-source inverter (VSI)

ASJC Scopus subject areas

  • Control and Systems Engineering
  • Electrical and Electronic Engineering

Fingerprint Dive into the research topics of 'A robust control scheme for grid-connected voltage-source inverters'. Together they form a unique fingerprint.

Cite this