Open AccessUnbalanced PCC voltage regulation with positive‐ and negative‐sequence compensation tactics for MMC‐DSTATCOM
Author(s) -
Xu Chen,
Dai Ke,
Chen Xinwen,
Kang Yong
Publication year - 2016
Publication title -
iet power electronics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.637
H-Index - 77
eISSN - 1755-4543
pISSN - 1755-4535
DOI - 10.1049/iet-pel.2015.1038
Subject(s) - control theory (sociology) , voltage , sequence (biology) , compensation (psychology) , h bridge , power (physics) , voltage compensation , modular design , voltage regulation , ac power , computer science , engineering , control (management) , pulse width modulation , electrical engineering , physics , chemistry , psychology , biochemistry , artificial intelligence , quantum mechanics , psychoanalysis , operating system
Unbalanced voltage fluctuation at the point of common coupling (PCC) is a challenging power quality problem in power distribution system. This study presents an unbalanced PCC voltage regulation scheme with positive‐ and negative‐sequence control for modular multilevel converter (MMC) in medium‐voltage distribution static synchronous compensator (DSTATCOM) application. The proposed positive‐sequence control is utilised to regulate the positive‐sequence component of PCC voltage to rated value, while the negative‐sequence control aims to cancel out the negative‐sequence component of PCC voltage completely. Compensation commands whether in positive‐ or negative‐sequence control are generated from unbalanced PCC voltage without utilisation of unbalanced load currents. DC circulating currents transferring active power among three phases of MMC are also analysed to illustrate power balance issue resulting from negative‐sequence control. Then comparison of negative‐sequence compensation capacity between MMC and full‐bridge cascaded converter with delta‐connection is illustrated. Experiment results acquired from a downscaled 85 V/1.5 kVA apparatus validate the effectiveness of the proposed control scheme.