Open AccessModified droop control for improving adaptive virtual impedance strategy for parallel distributed generation units in islanded microgrids
Author(s) -
Sabzevari Kiomars,
Karimi Shahram,
Khosravi Farshad,
Abdi Hamdi
Publication year - 2019
Publication title -
international transactions on electrical energy systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.428
H-Index - 42
ISSN - 2050-7038
DOI - 10.1002/etep.2689
Subject(s) - voltage droop , microgrid , voltage drop , control theory (sociology) , electrical impedance , voltage , computer science , compensation (psychology) , distributed generation , ac power , output impedance , voltage compensation , electronic engineering , reduction (mathematics) , engineering , voltage source , control (management) , electrical engineering , psychology , geometry , mathematics , artificial intelligence , renewable energy , psychoanalysis
Summary This paper proposes a control strategy to improve adaptive virtual impedance performance. The proposed method compensates voltage drop across the output impedances of distributed generation (DG) units, intensified due to the use of virtual impedance, and regulates the voltage of busses feeding microgrid‐connected loads in a desired level. In addition, it preserves the advantages of adaptive virtual impedance strategy, including proper active and reactive power sharing and decreased circulating current among parallel DGs. To compensate voltage drop proportional to load variation, the reference voltage used in the droop control strategy is adaptively regulated. To evaluate the performance and efficacy of the proposed control strategy, it was implemented on an islanded microgrid with two DGs. Simulation results show that the proposed strategy makes a compromise between control objectives, including appropriate power sharing, compensation of voltage drop, and reduction of circulating current.