Enhanced Stability Criteria of Network-Based Load Frequency Control of Power Systems with Time-Varying Delays

The stability problem for load frequency control (LFC) of power systems with two time-varying communication delays is studied in this paper. The one-area and two-area LFC systems are considered, respectively, which are modeled as corresponding linear systems with additive time-varying delays. An improved stability criterion is proposed via a modified Lyapunov-Krasovskii functional (LKF) approach. Firstly, an augmented LKF consisting of delay-dependent matrices and some single-integral items containing time-varying delay information in two different delay subintervals is constructed, which makes full use of the coupling information between the system states and time-varying delays. Secondly, the novel negative definite inequality equivalent transformation lemma is used to transform the nonlinear inequality to the linear matrix inequality (LMI) equivalently, which can be easily solved by the MATLAB LMI-Toolbox. Finally, some numerical examples are presented to show the improvement of the proposed approach.

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An Improved Stability Criterion for Load Frequency Control of Power Systems with Time-Varying Delays

Energies ◽

10.3390/en13082101 ◽

2020 ◽

Vol 13 (8) ◽

pp. 2101

Author(s):

Bi-Ying Chen ◽

Xing-Chen Shangguan ◽

Li Jin ◽

Dan-Yun Li

Keyword(s):

Power Systems ◽

Stability Criterion ◽

Frequency Control ◽

Load Frequency Control ◽

Linear Matrix ◽

Time Varying ◽

Time Varying Delay ◽

Load Frequency ◽

Improved Stability ◽

The Stability

This paper aims at developing a novel stability criterion to access the influence of the time-varying delay on the stability of power systems equipped with a proportional-integral (PI)-based load frequency control (LFC). The model of the LFC scheme considering time-varying communication delays is established at first. Then, an improved stability condition related to the information of delay bounds is deduced by constructing an augmented Lyapunov–Krasovski functional and using a matrix inequality, and it is expressed as linear matrix inequalities (LMIs) for easily checking. Finally, case studies for one-area and two-area LFC systems are carried out to show the relationship between delay margins ensuring the stability and the PI gains of the LFC, and also verify the superiority of proposed stability criterion compared with the previous ones.

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Further Stability Analysis for Load Frequency Control of Power Systems with Time-Varying Delays

10.23919/ccc52363.2021.9550684 ◽

2021 ◽

Author(s):

Wenxi Feng ◽

Fei Luo ◽

Xianyong Zhang ◽

Wenyong Duan

Keyword(s):

Stability Analysis ◽

Power Systems ◽

Frequency Control ◽

Load Frequency Control ◽

Time Varying ◽

Load Frequency

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Iterative linear matrix inequality algorithm based decentralized controller for load frequency control of two-area thermal power systems

2013 International Conference on Power, Energy and Control (ICPEC) ◽

10.1109/icpec.2013.6527695 ◽

2013 ◽

Cited By ~ 2

Author(s):

S. K. Pandey ◽

S. R. Mohanty ◽

N. Kishor ◽

R. P. Payasi

Keyword(s):

Power Systems ◽

Linear Matrix Inequality ◽

Frequency Control ◽

Thermal Power ◽

Load Frequency Control ◽

Linear Matrix ◽

Matrix Inequality ◽

Load Frequency ◽

Iterative Linear Matrix Inequality

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Observer-Based Sliding Mode Load Frequency Control of Power Systems under Deception Attack

Complexity ◽

10.1155/2021/8092206 ◽

2021 ◽

Vol 2021 ◽

pp. 1-11

Author(s):

Siwei Qiao ◽

Xinghua Liu ◽

Gaoxi Xiao ◽

Shuzhi Sam Ge

Keyword(s):

Sliding Mode Control ◽

Power Systems ◽

Sliding Mode ◽

Frequency Control ◽

State Equation ◽

The State ◽

Load Frequency Control ◽

Linear Matrix ◽

Mode Control ◽

Load Frequency

This study investigates the observer-based sliding mode load frequency control for multiarea interconnected power systems under deception attack. By introducing the observer and combining it with the system state equation, the expression of the system error is obtained. A sliding mode surface is proposed to make sure the state of the systems to be stable. Then, the state equation of the system under sliding mode control is derived. The asymptotic stability of the whole system is proved by using the linear matrix inequality (LMI) technique and Lyapunov stability theory. Furthermore, a sliding mode control law is proposed to ensure that the attacked power system can reach a stable position. Numerical simulation results are presented to support the correctness of the results.

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Robust H∞ Load Frequency Control of Power Systems Considering Intermittent Characteristics of Demand-Side Resources

Electronics ◽

10.3390/electronics9040593 ◽

2020 ◽

Vol 9 (4) ◽

pp. 593

Author(s):

Kun Yuan ◽

Zhetong Ding ◽

Yaping Li ◽

Mingyu Huang ◽

Kaifeng Zhang

Keyword(s):

Power Systems ◽

Control Method ◽

Frequency Control ◽

Load Frequency Control ◽

Linear Matrix ◽

Intermittent Control ◽

Demand Side ◽

Load Frequency ◽

The Stability ◽

The Impact

Recently, demand-side resources (DSRs) have proceeded to participate in frequency control of the power systems. Compared with traditional generation-side resources, DSRs have unique intermittent characteristics. Taking aggregation of air conditions as an example, they must take a break after providing power support for a period of time considering the user comfort. This behavior, known as the intermittent characteristic, obviously affects the stability of the power systems. Therefore, this paper designs a corresponding controller for DSRs based on the intermittent control method. The designed controller is incorporated into the traditional load frequency control (LFC) system. The time delay is also considered. A rigorous stability proof and the robust H ∞ performance analysis is presented for the new LFC system. Then, the sufficient robust frequency stabilization result is presented in terms of linear matrix inequalities (LMIs). Finally, a two-area power system is provided to illustrate the obtained results. The results show that the designed intermittent controller can mitigate the impact of intermittent characteristics of DSRs.

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