Wide-Area Time-Delay Coordinating Control of Generator Excitations and SVCs Based on Hamiltonian Functional Method

2014 ◽  
Vol 852 ◽  
pp. 675-680
Author(s):  
Gulizhati Hailati ◽  
Jie Wang ◽  
Ting Yin
Keyword(s):  
Time Delay ◽  
Power System ◽  
Sufficient Conditions ◽  
Functional Method ◽  
Wide Area ◽  
Delay Effect ◽  
Coordinating Control ◽  
The Stability ◽  
Delay Dependent ◽  
Wide Area Damping Controller

The stability of generator excitations and SVCs in power system with wide-area time-delay coordinating Control is investigated in this paper. A nonlinear time-delay Hamiltonian model of power system with SVCs is constructed and the Hamiltonian functional method is used to derive a delay-dependent steady stability criterion in term of matrix inequalities by constructing suitable Lyapunov-Krasovskii functional. Then the wide-area damping controller (WADC) and wide-area damping supplementary controller (WDSC) for the power system is designed based on the delay-dependent sufficient conditions. Four-generator eleven-bus power system is used to illustrate delay effect on inter-area mode damping. The performance of the proposed controller is verified by the results of simulation in time-domain, and it is proved that the method proposed in this paper is effective.

scholarly journals Mathematical analysis of a cancer model with time-delay in tumor-immune interaction and stimulation processes

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Kaushik Dehingia ◽  
Hemanta Kumar Sarmah ◽  
Yamen Alharbi ◽  
Kamyar Hosseini
Keyword(s):  
Time Delay ◽  
Immune Responses ◽  
Periodic Solutions ◽  
Equilibrium Points ◽  
Sufficient Conditions ◽  
Cancer Model ◽  
Delay Effect ◽  
Discrete Time Delay ◽  
The Stability ◽  
Vital Parameters

AbstractIn this study, we discuss a cancer model considering discrete time-delay in tumor-immune interaction and stimulation processes. This study aims to analyze and observe the dynamics of the model along with variation of vital parameters and the delay effect on anti-tumor immune responses. We obtain sufficient conditions for the existence of equilibrium points and their stability. Existence of Hopf bifurcation at co-axial equilibrium is investigated. The stability of bifurcating periodic solutions is discussed, and the time length for which the solutions preserve the stability is estimated. Furthermore, we have derived the conditions for the direction of bifurcating periodic solutions. Theoretically, it was observed that the system undergoes different states if we vary the system’s parameters. Some numerical simulations are presented to verify the obtained mathematical results.

Gobal Optimization Based Power System Stablization with WAMS Time Delay Study

2012 ◽  
Vol 433-440 ◽  
pp. 7362-7367
Author(s):  
Zhang Lin ◽  
Di Chen Liu ◽  
Wu Jun ◽  
Qing Fen Liao ◽  
Yun Lei ◽  
...  
Keyword(s):  
Global Optimization ◽  
Time Delay ◽  
Power System ◽  
Low Frequency ◽  
System Stability ◽  
Area Measurement ◽  
Wide Area ◽  
Linear Matrix ◽  
Feedback Signal ◽  
The Stability

It is very important to take into consideration time delay in wide area power system stability; the design of PSS (Power System Stabilizer) should consider global optimization with WAMS (Wide Area Measurement System) time delay. Newly designed PSS should be insensitive to time delay and suppress internal low frequency oscillations. It is used as feedback signal and is real-time synchronous that WAMS signal shows. Power system is modeled with the consideration of time delay. LMI (Linear Matrix Inequalities) is used to solve the stability condition of time delay system. Based on the time-delay effect of the wide-area measurement signals, this paper redesigned the PSS with global optimization of power system. The attached two-area-four-machine system simulation illustrates that wide-area PSS designed by global optimization with the consideration of time-delay can limit internal low frequency oscillation with time-delay insensitivity, and improve the stability of power system. It implements global optimization of PSS with WAMS time delay stability.

scholarly journals Sssc Based Time Delay Compensator Design for Interconnected Power System

2019 ◽  
Vol 8 (11) ◽  
pp. 4117-4121
Keyword(s):  
Time Delay ◽  
Power System ◽  
System Stability ◽  
Area Measurement ◽  
Wide Area ◽  
Feedback Signal ◽  
Signal Delay ◽  
Interconnected Power System ◽  
Wide Area Measurement System ◽  
Delay Dependent

In this paper, researcher designed a delay-dependent wide-area damping controller based on Static Synchronous Series Compensator (SSSC) to enhance the power system stability by using remote signal obtained from Wide-Area Measurement System (WAMS). This remote signals introduces a time delay in the feedback signal, as a result, degrade the system damping performance and even causes instability of close loop power system. To find out various controller parameters, use of Genetic Algorithm (GA) is adopted. The performance of Multi-Machines system is evaluated with proposed controller including signal delay and Conventional PSS(CPSS) in MATLAB simulation. Various results show that SSSC based controller damp-out the inter-area oscillations under small disturbance more effectively as compare to LPSS

scholarly journals The Delay-Dependent DOFC for Damping Inter-Area Low-Frequency Oscillations in an Interconnected Power System Considering Packet Loss of Wide-Area Signals

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5892
Author(s):  
Miaoping Sun ◽  
Yaosheng Guo ◽  
Seyha Song
Keyword(s):  
Power System ◽  
Packet Loss ◽  
Sufficient Conditions ◽  
Low Frequency ◽  
Wide Area ◽  
Interconnected Power System ◽  
Low Frequency Oscillations ◽  
Dynamic Output Feedback Controller ◽  
Delay Dependent ◽  
Model Reduction Technique

In this paper, the inter-area low-frequency oscillations are restrained in the interconnected power system by making use of the delay-dependent wide-area dynamic output feedback controller (DOFC). Modal analysis is adopted to obtain the modes of inter-area oscillation to be controlled and the Schur truncation model reduction technique is represented to reduce the order of the power system. The augmented closed-loop system model, where the transmission delay and packet loss of wide-area signals are considered, is established. The sufficient conditions of exponentially mean-square stable are obtained according to Lyapunov’s stability theory. Finally, case studies are carried out on a two-area four-machine power system, where our proposed controller, a conventional controller, and the wide-area damping controller in the existing references are installed, respectively. The simulation results under different external disturbances, packet loss rates, and delays are presented to show the effectiveness and advantages of our proposed controller.

scholarly journals Delay-Dependent Robust Stabilization for Nonlinear Large Systems via Decentralized Fuzzy Control

2011 ◽  
Vol 2011 ◽  
pp. 1-20 ◽  
Author(s):  
Chun-xia Dou ◽  
Zhi-sheng Duan ◽  
Xing-bei Jia ◽  
Xiao-gang Li ◽  
Jin-zhao Yang ◽  
...  
Keyword(s):  
Time Delay ◽  
Fuzzy Control ◽  
Upper Bound ◽  
Time Delays ◽  
Sufficient Conditions ◽  
Large System ◽  
Disturbance Attenuation ◽  
Robust Controller ◽  
Large Systems ◽  
Delay Dependent

A delay-dependent robust fuzzy control approach is developed for a class of nonlinear uncertain interconnected time delay large systems in this paper. First, an equivalent T–S fuzzy model is extended in order to accurately represent nonlinear dynamics of the large system. Then, a decentralized state feedback robust controller is proposed to guarantee system stabilization with a prescribedH∞disturbance attenuation level. Furthermore, taking into account the time delays in large system, based on a less conservative delay-dependent Lyapunov function approach combining with linear matrix inequalities (LMI) technique, some sufficient conditions for the existence ofH∞robust controller are presented in terms of LMI dependent on the upper bound of time delays. The upper bound of time-delay and minimizedH∞performance index can be obtained by using convex optimization such that the system can be stabilized and for all time delays whose sizes are not larger than the bound. Finally, the effectiveness of the proposed controller is demonstrated through simulation example.

scholarly journals Global Exponential Robust Stability of Static Interval Neural Networks with Time Delay in the Leakage Term

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
Guiying Chen ◽  
Linshan Wang
Keyword(s):  
Neural Networks ◽  
Time Delay ◽  
Robust Stability ◽  
Sufficient Conditions ◽  
Leakage Term ◽  
Interval Neural Networks ◽  
Global Exponential Robust Stability ◽  
The Stability ◽  
Delay Differential ◽  
Delay Differential Inequality

The stability of a class of static interval neural networks with time delay in the leakage term is investigated. By using the method ofM-matrix and the technique of delay differential inequality, we obtain some sufficient conditions ensuring the global exponential robust stability of the networks. The results in this paper extend the corresponding conclusions without leakage delay. An example is given to illustrate the effectiveness of the obtained results.

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