Open AccessAvoiding overvoltage problems in three‐phase distributed‐generation systems during unbalanced voltage sags
Author(s) -
Castilla Miguel,
Camacho Antonio,
Miret Jaume,
Guzmán Ramón,
García de Vicuña Luis
Publication year - 2020
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.2019.1178
Subject(s) - overvoltage , grid code , voltage , grid , electrical impedance , equivalent impedance transforms , ac power , control theory (sociology) , cascade , computer science , engineering , control (management) , electronic engineering , electrical engineering , geometry , mathematics , artificial intelligence , chemical engineering
During voltage sags, distributed generation systems must fulfil specific grid‐code requirements for reactive current injection. This ancillary service can produce overvoltage problems in networks operating in unbalanced conditions when the amplitude of one of the phase voltages is higher than the others and a balanced reactive current is injected through large grid impedance. This study proposes a control scheme to avoid these overvoltage problems, thus reducing the risk of cascade disconnection that this incident may produce. The derivation of the control scheme starts from the flexible oscillating‐power control, introduces the necessary modifications so that this control meets the grid‐code requirements for current injection and combines it with a slope voltage control to achieve a good voltage regulation. A theoretical analysis is included to determine the expressions that quantify the voltage support characteristics of the proposal. Finally, selected experimental results are reported to validate the characteristics of the proposed control.