Paper Info
Title
Virtual Impedance-Based Droop Control Scheme to Avoid Power Quality and Stability Problems in VSI-Dominated Microgrids
Abstract
Droop-based techniques have widely been utilized in controlling voltage source inverter based distributed generation units within a microgrid. Advantages of droop based control have been extensively discussed, while its effects on stability and power quality of the inverter based microgrids have not been explicitly studied. This paper addresses this gap by analyzing the stability of islanded microgrid with focusing on power quality problems. From this viewpoint, current paper studies the effect of parameters change on the stability margin of the microgrid using a bifurcation analysis approach. To this end, this work firstly derives a dynamic model of a microgrid including controllers of the inverter, network and loads. Based on this model, the loci of the system eigenvalues have been analyzed, showing that, by changing the droop coefficients, the hopf and period doubling bifurcation can occur in such a system. Furthermore, the droop tuning procedure may also cause the system to experience the flicker phenomenon in advance of the instability. Next, a virtual impedance-based solution is presented to avoid the flicker as well as instability problems. Finally, the efficacy of the proposed method is proved on a practical network.
Year
DOI
Venue
2021
10.1109/ACCESS.2021.3122800
IEEE ACCESS
Keywords
DocType
Volume
Voltage control, Power system stability, Impedance, Microgrids, Power quality, Frequency control, Bifurcation, Droop control, power quality, stability, microgrid
Journal
9
ISSN
Citations 
PageRank 
2169-3536
0
0.34
References 
Authors
0
4
Name
Order
Citations
PageRank
Babak Keyvani-Boroujeni100.34
Bahador Fani200.34
Shahgholian, G.301.01
Hassan Haes Alhelou4813.42