An Improved Droop Control Strategy for Low-Voltage Microgrids Based on Distributed Secondary Power Optimization Control

Demin Li, Bo Zhao, Zaijun Wu, Xuesong Zhang and Leiqi Zhang
Additional contact information
Demin Li: School of Electrical Engineering, Southeast University, Nanjing 210096, China
Bo Zhao: State Grid Zhejiang Electric Power Research Institute, Hangzhou 310014, China
Zaijun Wu: School of Electrical Engineering, Southeast University, Nanjing 210096, China
Xuesong Zhang: State Grid Zhejiang Electric Power Research Institute, Hangzhou 310014, China
Leiqi Zhang: State Grid Zhejiang Electric Power Research Institute, Hangzhou 310014, China

Energies, 2017, vol. 10, issue 9, 1-18

Abstract: To achieve accurate reactive power sharing and voltage frequency and amplitude restoration in low-voltage microgrids, a control strategy combining an improved droop control with distributed secondary power optimization control is proposed. The active and reactive power that each distributed generator (DG) shares is calculated by extracting load information and utilizing a power sharing ratio, and is reset to be the nominal power to recalculate droop gains. The droop control curves are reconstructed according to the nominal active and reactive power and the recalculated droop gains. The reconstructed active power-frequency droop control can regulate active power adaptively and keep frequency at a nominal value. Meanwhile, the reconstructed reactive power voltage droop control can reduce voltage amplitude deviation to a certain extent. A distributed secondary power optimization control is added to the reconstructed reactive power voltage droop control by using average system voltage. The average system voltage is obtained by using a consensus algorithm in a distributed, sparse communication network which is constituted by all controllers of DGs. As a result, accurate reactive power sharing is realized, average system voltage is kept at a nominal value, and all voltage amplitude deviations are further reduced. Due to the absence of a microgrid central controller, the reliability of the strategy is enhanced. Finally, the simulation results validate the proposed method.

Keywords: low-voltage microgrids; improved droop control; distributed secondary power optimization control; consensus algorithm; accurate reactive power sharing (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2017
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (11)

Downloads: (external link)
https://www.mdpi.com/1996-1073/10/9/1347/pdf (application/pdf)
https://www.mdpi.com/1996-1073/10/9/1347/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:10:y:2017:i:9:p:1347-:d:111158

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().