scholarly journals Wide-AreaH∞Control for Damping Interarea Oscillations with Event-Triggered Scheme

2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
Yunning Zhang ◽  
Dong Yue ◽  
Songlin Hu

An event-triggered scheme is adopted and applied to the design of a centralized wide-areaH∞damping controller (WAHDC) of interconnected power systems with external disturbance. Firstly, based on the linearized multimachine system model, the centralized WAHDC with event-triggered scheme design problem is described as time-delay feedback control problem. Then by using Lyapunov functional method and Jensen inequality technique, criteria for stability with anH∞norm bound and for design of the feedback controller are derived. The linear matrix inequality (LMI) is employed to solve the feedback gain. Finally, case studies are carried out based on two-area four-machine power system. Simulations indicate that the proposed WAHDC with event-triggered scheme can damp the interarea oscillation effectively when the external disturbance is bounded and significantly reduce the number of measured states released to WAHDC. Relationships between event trigger parameterσand dynamic performance,σand network utilization,σand time delay, andσand disturbance rejection level are investigated and results obtained can be used to choose an appropriate event trigger parameter.

2013 ◽  
Vol 347-350 ◽  
pp. 695-700
Author(s):  
Shuai Tian He ◽  
Zhi Chang Li

The stability analysis and controller design of discrete linear systems with time-varying delay are addressed. Firstly, the uniformly asymptotical stability criterion with adjustable parameter is derived by Lyapunov-Razumikhin approach. Then, the stabilization approaches for linear systems with time delay by state feedback and observer based-on state feedback are also presented. Sufficient conditions for the existence of state feedback gain and the observer gain are derived through the numerical solution of a set of obtained linear matrix inequalities. Compared with methods in the references, the dynamic performance of systems, such as the overshoot and the convergence rate of the response, can be adjusted by changing the adjustable parameter. Lastly, an illustrative example is given to show the effectiveness of the proposed.


2012 ◽  
Vol 235 ◽  
pp. 254-258 ◽  
Author(s):  
Shao Hua Long ◽  
Shou Ming Zhong

The problem of the stochastic admissibility for a class of nonlinear singular Markovian jump systems with time-delay and partially unknown transition probabilities is discussed in this note. The considered singular matrices Er(t) in the discussed system are mode-dependent. By using the free-weighting matrix method and the Lyapunov functional method, a sufficient condition which guarantees the considered system to be stochastically admissible is presented in the form of linear matrix inequalities(LMIs). Finally, a numerical example is given to show the effectiveness of the presented method.


2011 ◽  
Vol 18 (11) ◽  
pp. 1631-1649 ◽  
Author(s):  
Zhao Tong ◽  
Chen Long-Xiang ◽  
Cai Guo-Ping

This paper presents theoretical and experimental studies of H∞ control for a flexible plate. Firstly, the dynamic equation of the plate with time delay is established with consideration of external disturbance. Then the standard state equation without explicit time delay is deduced by using a particular integral transformation to the time-delay equation. Finally, a H∞ time-delay controller is designed based on the standard state equation using the method of linear matrix inequality. In the controller designed, it contains not only the current step of state feedback but also the linear combination of some former steps of control. In the experiment, piezoelectric patches are used as actuators and sensors. The experiment system is structured based on the DSP TMS320F2812. Single time delay and double time delay are both considered in the experiment. The robustness of H∞ controller against the structural parameter of the plate and time delay is experimentally investigated. Simulation and experimental results indicate that the control system may suffer from instability if time delay is not treated in control design. The time-delay controller presented in this paper can effectively deal with time delay in the system, and is available for small-time delay and large-time delay as well. Furthermore, this delay controller is robust to the variance of structural parameter of the plate and time delay.


2017 ◽  
Vol 66 (3) ◽  
pp. 459-474
Author(s):  
Hamid Reza Koofigar ◽  
Ghader Isazadeh

AbstractA robust auxiliary wide area damping controller is proposed for a unified power flow controller (UPFC). The mixedH2/H∞problem with regional pole placement, resolved by linear matrix inequality (LMI), is applied for controller design. Based on modal analysis, the optimal wide area input signals for the controller are selected. The time delay of input signals, due to electrical distance from the UPFC location is taken into account in the design procedure. The proposed controller is applied to a multi-machine interconnected power system from the IRAN power grid. It is shown that the both transient and dynamic stability are significantly improved despite different disturbances and loading conditions.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Xiaofang Kang ◽  
Jian Wu ◽  
Yewei Zhang ◽  
Guoliang Liu ◽  
Suhui Zhang ◽  
...  

A decentralized control strategy can effectively solve the control problem of the large-scale time delayed structures. In this paper, combining the overlapping decentralized control method, linear matrix inequality (LMI) method, and H∞ control algorithm, overlapping decentralized H∞ control approach of the time delayed structures has been established. The feedback gain matrixes of all subsystems are obtained by this method based on genetic algorithm optimization tools and the specific goal of optimization control. The whole vibration control system of the time delayed structures is divided into a series of overlapping subsystems by overlapping decentralized control strategy. The feedback gain matrixes of each subsystem can be obtained by using H∞ control algorithm to calculate each subsystem. The vibration control of a twenty layers’ antiseismic steel structure Benchmark model was analyzed with the numerical method. The results show that the proposed method can be applied to control system with time delay. The overlapping decentralized control strategies acquire the similar control effects with that of the centralized control strategy. Moreover, the flexibility of the controller design has been enhanced by using overlapping decentralized control strategies.


2019 ◽  
Vol 37 (3) ◽  
pp. 918-934
Author(s):  
Jing Bai ◽  
Ying Wang ◽  
Li-Ying Zhao

Abstract This paper is concerned with the discrete event-triggered dynamic output-feedback ${H}_{\infty }$ control problem for the uncertain networked control system, where the time-varying sampling, network-induced delay and packet losses are taken into account simultaneously. The random packet losses are described via the Bernoulli distribution. And then, the closed-loop system is modelled as an augmented time-delay system with interval time-varying delay. By using the Lyapunov stability theory and the augmented state space method, the sufficient conditions for the asymptotic stability of the closed-loop system are proposed in the form of linear matrix inequalities. At the same time, the design method of the ${H}_{\infty }$ controller is created. Finally, a numerical example is employed to illustrate the effectiveness of the proposed method.


2016 ◽  
Vol 11 (1) ◽  
pp. 83-92
Author(s):  
Liu Quansheng ◽  
Xu Min ◽  
Peng Li

In order to achieve the consistency of multi-agent systems, each agent needs to communicate with its adjacent agents, which will consume energy of sensors embedded on the agents and occupy network bandwidth of multi-agent systems. Both resources are limited. To solve the above problem, a novel distributed event-triggered scheme of discrete-time second-order multi-agent systems are proposed in this article. The characteristics of the scheme have two aspects. Firstly, the event-triggered conditions are considered for the state and the velocity separately. Secondly, when the event is triggered on an agent, the agent only communicates with its local neighbors. Then, the agent and its local neighbors update their controls while the other agents' controllers remain unchanged. So the scheme can maximize reduction of the sensor energy consuming and communication burden in the multi-agent network. Based on the Lyapunov functional method, a sufficient condition is obtained to achieve the stability of the second-order multi-agent systems in terms of linear matrix inequality. Finally, numerical examples are presented to validate the proposed event-triggered consensus control.


2018 ◽  
Vol 2018 ◽  
pp. 1-12
Author(s):  
Sha-sha Li ◽  
Zhan-shan Zhao ◽  
Jing Zhang ◽  
Jie Sun ◽  
Lian-kun Sun

The issue of H∞ control for the coronary artery input time-delay system with external disturbance is of concern. To further reduce conservation, we utilize the free-matrix-based integral inequality, Wirtinger-based integral inequality, and reciprocal convex combination approach to construct Lyapunov-Krasovskii function (LKF). Then a sufficient condition for controller design which can guarantee robust synchronization the coronary artery system is represented in terms of linear matrix inequality (LMI). Finally, a numerical example is exploited to show the effectiveness of the proposed methods.


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