Grid-Current-Feedback Control for LCL-Filtered Grid Converters With Enhanced Stability

This paper proposes a second-order-generalized-integrator (SOGI)-based time-delay compensation method for extending the stable region of a dual-loop grid-current-feedback (GCF) control system. According to the analysis, stable region of the dual-loop system should be designed below a certain critica...

Full description

Saved in:
Bibliographic Details
Published in:IEEE transactions on power electronics 2017-04, Vol.32 (4), p.3216-3228
Main Authors: Zhen Xin, Xiongfei Wang, Poh Chiang Loh, Blaabjerg, Frede
Format: Article
Language:English
Subjects:
<italic xmlns:ali="http://www.niso.org/schemas/ali/1.0/" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">LCL -filter
Active damping (AD)
Compensation
Control stability
Control systems
Converters
current control
Delay
Delay effects
Delays
Feedback control
Power system stability
Resonant frequency
Robustness
stability
Stability criteria
voltage-source converter
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:This paper proposes a second-order-generalized-integrator (SOGI)-based time-delay compensation method for extending the stable region of a dual-loop grid-current-feedback (GCF) control system. According to the analysis, stable region of the dual-loop system should be designed below a certain critical frequency, before time-delay compensation method can be applied. To always meet the requirement, relationship between single-loop converter-current-feedback and dual-loop GCF control is clarified, before a robust inner-loop gain for the dual-loop GCF scheme is determined. Enforcing this gain allows the converter to remain in its stable region, regardless of how its LCL -filter parameters and grid impedance vary. The SOGI-based delay compensation method can then be applied for widening the stable region of the dual-loop GCF scheme, as proven through s-domain Bode diagrams and z -domain root loci. These theoretical proofs are eventually validated by experimental results obtained in the laboratory.
ISSN:0885-8993
1941-0107
DOI:10.1109/TPEL.2016.2580543