Document Type
Article
Publication Date
7-10-2018
Subject: LCSH
Distributed generation of electric power
Disciplines
Computer Engineering | Computer Sciences | Electrical and Computer Engineering
Abstract
It is difficult to achieve accurate distribution of reactive power based on conventional droop control due to the line impedance mismatch in an islanded microgrid. An adaptive virtual impendence method based on consensus control of reactive current is proposed in this paper. A distributed control structure without the central controller has been established. In this structure, each distributed generation unit (DG) is an independent agent, one-way communication is used between the adjacent DGs, and the reactive power sharing is equivalent to a problem of reactive power current consensus. It has been proven that the system is asymptotically stable under the proposed control strategy. When the adjacent DG’s reactive power is not proportionally distributed, the current weight error term will generate a virtual impedance correction term through the proportional-integral controller based on the reactive current consensus control strategy, thus introducing adaptive virtual impedance to eliminate mismatches in output impedance between DGs. Reactive power auto-proportional distribution can be achieved without knowing the line impedance. At the same time, the power control loop is simplified and the virtual impedance compensation angle is employed to compensate the decreased reference voltage magnitude and varied phase angle due to the introduction of the virtual impedance, so the stability of the system can be improved. Finally, the correctness and effectiveness of the proposed strategy are verified by modeling analysis and microgrid simulations.
Abstract
It is difficult to achieve accurate distribution of reactive power based on conventional droop control due to the line impedance mismatch in an islanded microgrid. An adaptive virtual impendence method based on consensus control of reactive current is proposed in this paper. A distributed control structure without the central controller has been established. In this structure, each distributed generation unit (DG) is an independent agent, one-way communication is used between the adjacent DGs, and the reactive power sharing is equivalent to a problem of reactive power current consensus. It has been proven that the system is asymptotically stable under the proposed control strategy. When the adjacent DG’s reactive power is not proportionally distributed, the current weight error term will generate a virtual impedance correction term through the proportional-integral controller based on the reactive current consensus control strategy, thus introducing adaptive virtual impedance to eliminate mismatches in output impedance between DGs. Reactive power auto-proportional distribution can be achieved without knowing the line impedance. At the same time, the power control loop is simplified and the virtual impedance compensation angle is employed to compensate the decreased reference voltage magnitude and varied phase angle due to the introduction of the virtual impedance, so the stability of the system can be improved. Finally, the correctness and effectiveness of the proposed strategy are verified by modeling analysis and microgrid simulations.
DOI
10.3390/en11071801
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
Repository Citation
Lu, Zhilin; Wei, Qing; Zhang, Yiyi; Zhao, Junhui; and Manla, Emad, "Adaptive Virtual Impedance Droop Control Based on Consensus Control of Reactive Current" (2018). Electrical & Computer Engineering and Computer Science Faculty Publications. 90.
https://digitalcommons.newhaven.edu/electricalcomputerengineering-facpubs/90
Publisher Citation
Lyu, Z.; Wei, Q.; Zhang, Y.; Zhao, J.; Manla, E. Adaptive Virtual Impedance Droop Control Based on Consensus Control of Reactive Current. Energies 2018, 11, 1801.
Included in
Computer Engineering Commons, Computer Sciences Commons, Electrical and Computer Engineering Commons
Comments
This article was published open access under a CC-BY license in the journal Energies. The original posting is at https://doi.org/10.3390/en11071801 . Everyone is free to re-use the published material if proper accreditation/citation of the original publication is given.