Open AccessComprehensive local control design for eliminating line resistance effect on power sharing degradation in DC microgrids
Author(s) -
Li Fulong,
Lin Zhengyu,
Xu Haoge,
Wang Fei
Publication year - 2021
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/pel2.12208
Subject(s) - microgrid , voltage droop , control theory (sociology) , voltage drop , controller (irrigation) , voltage , engineering , electronic engineering , computer science , voltage regulator , electrical engineering , control (management) , agronomy , artificial intelligence , biology
In droop‐controlled DC microgrids, parasitic resistances of long conductive lines introduce additional terms for the power calculation and impact the power sharing accuracy. This paper proposed a comprehensive local control design for enhancing power sharing accuracy and restoring DC bus voltage while increasing stability performance in DC microgrids. A passive controller is used in the primary control to ensure the sufficient bandwidth of controller in case of frequent operation modes alteration and voltage deviation in the DC microgrid. A concept of Virtual Negative Line Resistance (VNLR) is used in the secondary control layer to compensate the real line resistance such that line resistance no longer degrades power sharing accuracy. The common DC bus voltage needs to be monitored in the proposed secondary controller. Simultaneously, the common DC bus voltage can be restored as the designed value. The monitored DC bus voltage signal is filtered by a designed low‐pass filter such that mid‐high frequency dynamics can be decoupled between secondary controls and primary controls. Then the entire local control scheme relaxes three Degrees of Freedom (DoF) which can be used for upper layer controls. Finally, the proposed control method has been experimentally validated in a 50 V DC microgrid laboratory testing system.