This paper investigates the problem of a delay-dependent stability analysis in power systems, where the communication delay is modeled as a continuous, differentiable, aperiodic, and bounded function with constrained derivatives. First, a unified load frequency control system model is formulated that explicitly incorporates time-varying delays. Then, to more accurately address the delay characteristics, a monotonic interval partitioning strategy is introduced, which divides the delay trajectory into multiple segments based on its increasing or decreasing behavior. Each segment is associated with corresponding local extremal points of the delay function. Furthermore, to more effectively exploit the delay information, a new Lyapunov-Krasovskii functional (LKF) is developed, which integrates system states related to the local extremal values of the delay in each subinterval. By leveraging this LKF together with a convex combination method, less conservative stability conditions are derived. Finally, numerical case studies are presented to demonstrate the proposed approach's capability of enlarging the admissible delay bounds and validating its improved performance.
Citation: Shihao Wang, Jin Yang, Yuejiang Wang, Qishui Zhong, Kaibo Shi. Delay-dependent stability analysis of power system: A Monotone-Interval-Partition method for time-varying delays[J]. AIMS Mathematics, 2025, 10(7): 16746-16761. doi: 10.3934/math.2025752
This paper investigates the problem of a delay-dependent stability analysis in power systems, where the communication delay is modeled as a continuous, differentiable, aperiodic, and bounded function with constrained derivatives. First, a unified load frequency control system model is formulated that explicitly incorporates time-varying delays. Then, to more accurately address the delay characteristics, a monotonic interval partitioning strategy is introduced, which divides the delay trajectory into multiple segments based on its increasing or decreasing behavior. Each segment is associated with corresponding local extremal points of the delay function. Furthermore, to more effectively exploit the delay information, a new Lyapunov-Krasovskii functional (LKF) is developed, which integrates system states related to the local extremal values of the delay in each subinterval. By leveraging this LKF together with a convex combination method, less conservative stability conditions are derived. Finally, numerical case studies are presented to demonstrate the proposed approach's capability of enlarging the admissible delay bounds and validating its improved performance.
| [1] |
X. C. Shangguan, Y. He, C. K. Zhang, L. Jin, W. Yao, L. Jiang, et al., Control performance standards-oriented event-triggered load frequency control for power systems under limited communication bandwidth, IEEE Trans. Control Syst. Techn., 30 (2022), 860–868. https://doi.org/10.1109/TCST.2021.3070861 doi: 10.1109/TCST.2021.3070861
|
| [2] |
R. Zhu, C. Huang, S. Deng, Y. Li, Detection of false data injection attacks based on kalman filter and controller design in power system LFC, J. Phys. Conf. Ser., 1861 (2021), 012120. https://doi.org/10.1088/1742-6596/1861/1/012120 doi: 10.1088/1742-6596/1861/1/012120
|
| [3] |
N. Vafamand, M. M. Arefi, M. H. Asemani, T. Dragicevic, Decentralized robust disturbance-observer based lfc of interconnected systems, IEEE Trans. Ind. Electron., 69 (2022), 4814–4823. https://doi.org/10.1109/TIE.2021.3078352 doi: 10.1109/TIE.2021.3078352
|
| [4] |
M. M. Hossain, C. Peng, H. T. Sun, S. Xie, Bandwidth allocation-based distributed event-triggered LFC for smart grids under hybrid attacks, IEEE Trans. Smart Grid, 13 (2022), 820–830. https://doi.org/10.1109/TSG.2021.3118801 doi: 10.1109/TSG.2021.3118801
|
| [5] |
G. Zhang, J. Li, O. Bamisile, Y. Xing, D. Cai, Q. Huang, An H$_\infty$ load frequency control scheme for multi-area power system under cyber-attacks and time-varying delays, IEEE Trans. Power Syst., 38 (2023), 1336–1349. https://doi.org/10.1109/TPWRS.2022.3171101 doi: 10.1109/TPWRS.2022.3171101
|
| [6] |
L. Yang, T. Liu, D. J. Hill, Decentralized event-triggered frequency regulation for multi-area power systems, Automatica, 126 (2021), 109479. https://doi.org/10.1016/j.automatica.2020.109479 doi: 10.1016/j.automatica.2020.109479
|
| [7] |
T. N. Pham, S. Nahavandi, L. V. Hien, H. Trinh, K. P. Wong, Static output feedback frequency stabilization of time-delay power systems with coordinated electric vehicles state of charge control, IEEE Trans. Power Syst., 32 (2017), 3862–3874. https://doi.org/10.1109/TPWRS.2016.2633540 doi: 10.1109/TPWRS.2016.2633540
|
| [8] |
S. Saxena, E. Fridman, Event-triggered load frequency control via switching approach, IEEE Trans. Power Syst., 35 (2020), 4484–4494. https://doi.org/10.1109/TPWRS.2020.2999488 doi: 10.1109/TPWRS.2020.2999488
|
| [9] |
J. Yang, Q. Zhong, X. Liu, K. Shi, A. M. Y. M. Ghias, Z. Y. Dong, Decentralized periodic event-triggered load frequency control for multiarea power systems, IEEE Trans. Syst. Man Cybern. Syst., 55 (2025), 1020–1030. https://doi.org/10.1109/TSMC.2024.3493102 doi: 10.1109/TSMC.2024.3493102
|
| [10] |
R. Olfati-Saber, R. M. Murray, Consensus problems in networks of agents with switching topology and time-delays, IEEE Trans. Autom. Control, 49 (2004), 1520–1533. https://doi.org/10.1109/TAC.2004.834113 doi: 10.1109/TAC.2004.834113
|
| [11] |
J. Yang, Q. Zhong, H. Liang, K. Shi, Z. Y. Dong, Distributed observer-based dynamic-memory event-triggered security control for interconnected linear systems, IEEE Trans. Autom. Sci. Eng., 22 (2025), 9958–9969. https://doi.org/10.1109/TASE.2024.3515148 doi: 10.1109/TASE.2024.3515148
|
| [12] |
Y. Chen, Y. Li, G. Chen, New results on stability analysis for a class of generalized delayed neural networks, Appl. Math. Comput., 469 (2024), 128529. https://doi.org/10.1016/j.amc.2024.128529 doi: 10.1016/j.amc.2024.128529
|
| [13] |
M. J. Park, O. M. Kwon, J. H. Ryu, Generalized integral inequality: Application to time-delay systems, Appl. Math. Lett., 77 (2018), 6–12. https://doi.org/10.1016/j.aml.2017.09.010 doi: 10.1016/j.aml.2017.09.010
|
| [14] |
M. R. Chen, G. Q. Zeng, X. Q. Xie, Population extremal optimization-based extended distributed model predictive load frequency control of multi-area interconnected power systems, J. Franklin Inst., 355 (2018), 8266–8295. https://doi.org/10.1016/j.jfranklin.2018.08.020 doi: 10.1016/j.jfranklin.2018.08.020
|
| [15] |
X. C. Shang-Guan, Y. He, C. Zhang, L. Jiang, J. W. Spencer, M. Wu, Sampled-data based discrete and fast load frequency control for power systems with wind power, Appl. Energy, 259 (2020), 114202. https://doi.org/10.1016/j.apenergy.2019.114202 doi: 10.1016/j.apenergy.2019.114202
|
| [16] |
W. Wang, W. M. Wang, H. B. Zeng, Stability analysis of systems with cyclical delay via an improved delay-monotonicity-dependent Lyapunov functional, J. Franklin Inst., 360 (2023), 99–108. https://doi.org/10.1016/j.jfranklin.2022.11.032 doi: 10.1016/j.jfranklin.2022.11.032
|
| [17] |
H. B. Zeng, Y. He, K. L. Teo, Monotone-delay-interval-based Lyapunov functionals for stability analysis of systems with a periodically varying delay, Automatica, 138 (2022), 110030. https://doi.org/10.1016/j.automatica.2021.110030 doi: 10.1016/j.automatica.2021.110030
|
| [18] |
Y. Chen, H. B. Zeng, Y. Li, Stability analysis of linear delayed systems based on an allowable delay set partitioning approach, Automatica, 163 (2024), 111603. https://doi.org/10.1016/j.automatica.2024.111603 doi: 10.1016/j.automatica.2024.111603
|
| [19] |
Y. Chen, C. Lu, X. M. Zhang, Allowable delay set flexible fragmentation approach to passivity analysis of delayed neural networks, Neurocomputing, 629 (2025), 129730. https://doi.org/10.1016/j.neucom.2025.129730 doi: 10.1016/j.neucom.2025.129730
|
| [20] |
H. B. Zeng, S. J. Zhou, X. M. Zhang, W. Wang, Delay-dependent stability analysis of load frequency control systems with electric vehicles, IEEE Trans. Cybern., 52 (2022), 13645–13653. https://doi.org/10.1109/TCYB.2022.3140463 doi: 10.1109/TCYB.2022.3140463
|
| [21] |
P. Park, W. I. Lee, S. Y. Lee, Auxiliary function-based integral inequalities for quadratic functions and their applications to time-delay systems, J. Franklin Inst., 352 (2015), 1378–1396. https://doi.org/10.1016/j.jfranklin.2015.01.004 doi: 10.1016/j.jfranklin.2015.01.004
|
| [22] |
H. B. Zeng, X. G. Liu, W. Wang, A generalized free-matrix-based integral inequality for stability analysis of time-varying delay systems, Appl. Math. Comput., 354 (2019), 1–8. https://doi.org/10.1016/j.amc.2019.02.009 doi: 10.1016/j.amc.2019.02.009
|
| [23] |
W. H. Chen, C. K. Zhang, R. W. Chen, K. Y. Xie, Y. He, H. B. Zeng, A discrete-time looped functional approach and its application to discrete-time systems with cyclically varying delays, Sci. China Inf. Sci., 68 (2025), 182204. https://doi.org/10.1007/s11432-024-4220-6 doi: 10.1007/s11432-024-4220-6
|
| [24] |
C. K. Zhang, F. Long, Y. He, W. Yao, L. Jiang, M. Wu, A relaxed quadratic function negative-determination lemma and its application to time-delay systems, Automatica, 113 (2020), 108764. https://doi.org/10.1016/j.automatica.2019.108764 doi: 10.1016/j.automatica.2019.108764
|