Time-Varying Optimization-Based Consensus Control For Microgrid's Secondary Control

2021 ◽  
Author(s):  
Fahad Alshammari ◽  
Ayman El-Refaie
Keyword(s):  
Time Varying ◽  
Secondary Control ◽  
Consensus Control

Reduced-order observer-based consensus control of linear multi-agent systems over directed networks with nonuniform communication delays

2020 ◽  
pp. 014233122093430
Author(s):  
Qiuzhen Wang ◽  
Jiangping Hu ◽  
Yiyi Zhao ◽  
Bijoy Kumar Ghosh
Keyword(s):  
Time Varying ◽  
Communication Delays ◽  
Multi Agent Systems ◽  
Consensus Control ◽  
Reduced Order ◽  
Reduced Order Observer ◽  
Multi Agent ◽  
The Stability ◽  
Output Information ◽  
Theoretical Results

This paper considers a consensus control of a general linear multi-agent system with time-varying communication delays. Since each agent can only use the relative output information from its neighbors, a reduced-order observer-based control protocol is proposed to guarantee consensus on the directed communication network. The stability of the closed-loop system is analyzed for the cases with uniform delays and nonuniform time-varying delays, respectively. Moreover, the upper bounds of the communication delays are obtained respectively for the two cases. Finally, two numerical examples are provided to illustrate the proposed theoretical results.

scholarly journals Consensus Control for Reactive Power Sharing Using an Adaptive Virtual Impedance Approach

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 2026 ◽  
Author(s):  
Ahmed S. Alsafran ◽  
Malcolm W. Daniels
Keyword(s):  
Rate Of Convergence ◽  
Reactive Power ◽  
Impedance Control ◽  
Power Sharing ◽  
Control Methods ◽  
Triangle Mesh ◽  
Secondary Control ◽  
Consensus Control ◽  
Communication Topology ◽  
Virtual Impedance

Reactive power sharing among distributed generators (DGs) in islanded microgrids (MGs) presents control challenges, particularly in the mismatched feeder line condition. Improved droop control methods independently struggle to resolve this issue and centralized secondary control methods exhibit a high risk of collapse for the entire MG system under any failure in the central control. Distributed secondary control methods have been recently proposed to mitigate the reactive power error evident in the presence of mismatched feeder lines. This paper details a mathematical model of an adaptive virtual impedance control that is based on both leaderless and leader-followers consensus controls with a novel triangle mesh communication topology to ensure accurate active and reactive power sharing. The approach balances an enhanced rate of convergence with the anticipated implementation cost. A MATLAB/Simulink model with six DG units validates the proposed control performance under three different communication structures: namely, ring, complete, and triangle mesh topologies. The results suggest that leaderless consensus control is a reliable option with large DG systems, while the leader-followers consensus control is suitable for the small systems. The triangle mesh communication topology provides a compromise approach balancing the rate of convergence and the expected cost. The extensibility and scalability are advantages of this topology over the alternate ring and complete topologies.

Leader-Following Consensus Control of General Linear Multi-Agent Systems With Diverse Time-Varying Input Delays

2017 ◽  
Vol 140 (6) ◽  
Author(s):  
Chengzhi Yuan
Keyword(s):  
Single Agent ◽  
General Linear ◽  
Control Synthesis ◽  
Time Varying ◽  
Multi Agent Systems ◽  
Consensus Control ◽  
Agent Systems ◽  
Leader Following ◽  
Multi Agent ◽  
Input Delays

This paper addresses the problem of leader-following consensus control of general linear multi-agent systems (MASs) with diverse time-varying input delays under the integral quadratic constraint (IQC) framework. A novel exact-memory distributed output-feedback delay controller structure is proposed, which utilizes not only relative estimation state information from neighboring agents but also local real-time information of time delays and the associated dynamic IQC-induced states from the agent itself for feedback control. As a result, the distributed consensus problem can be decomposed into H∞ stabilization subproblems for a set of independent linear fractional transformation (LFT) systems, whose dimensions are equal to that of a single agent plant plus the associated local IQC dynamics. New delay control synthesis conditions for each subproblem are fully characterized as linear matrix inequalities (LMIs). A numerical example is used to demonstrate the proposed approach.

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