A Framework for Monitoring and Enhancing the Dynamic Stability of Islanded Multi-Microgrid Systems

Document Type : Original Article

Authors

1 Faculty of Engineering, Lorestan University, Khorramabad, Lorestan, Iran

2 Faculty of Engineering, Lorestan University, Khorramabad, Lorestan

Abstract

With the expansion of multi-microgrid networks incorporating inverter-based distributed energy resources (IBDER), maintaining and enhancing system stability has become a significant challenge. The complex interactions between microgrids and control levels can reduce the damping of system eigenvalues or modes. These low-damping modes (LDMs) degrade system stability and increase oscillations. To address this challenge, this paper presents a method for stability monitoring and enhancement in islanded multi-microgrid networks controlled through a three-level hierarchical structure. At the primary level, droop control is employed for power sharing among generation units. At the secondary level, voltage and frequency deviations from nominal values are restored using a distributed consensus method. At the tertiary level, the proposed method, known as Reduced Consensus Coefficient Estimation (RCCE), is utilized to monitor and improve system stability adaptively. In the RCCE method, the consensus coefficient is reduced until the damping of LDMs is enhanced, leading to improved dynamic system stability. Simulation results in MATLAB demonstrate that the proposed method effectively enhances stability and reduces frequency and voltage oscillations in multi-microgrid systems.

Keywords

Main Subjects


[1] Sorouri, M., Shakarami, M. R., Soltani, J., "Autonomous active power control for an islanded AC microgrid using improved bus signaling method", International Journal of Electrical Power & Energy Systems, Vol. 113, pp. 549-563, 2019,  https://doi.org/10.1016/j.ijepes.2019.05.070.
[2] Zhao, T., Liu, H., Su, J., Wang, N., Luo, Z., "Coordinated control for distributed energy resources in islanded microgrids with improved frequency regulation capability", Renewable Energy, p. 122690, 2025,  https://doi.org/10.1016/j.renene.2025.122690.
[3] Islam, M., Yang, F., Amin, M., "Control and optimisation of networked microgrids: A review", IET Renewable Power Generation, Vol. 15, No. 6, pp. 1133-1148, 2021,  https://doi.org/10.1049/rpg2.12111.
[4] Saadati Toularoud, M., Khoshhal Rudposhti, M., Bagheri, S., Salemi, A. H., "Enhancing microgrid voltage and frequency stability through multilayer interactive control framework", International Transactions on Electrical Energy Systems, Vol. 2024, No. 1, p. 4933861, 2024,  https://doi.org/10.1155/2024/4933861.
[5] Golsorkhi, M. S., Hill, D. J., Karshenas, H. R., "Distributed voltage control and power management of networked microgrids", IEEE Journal of Emerging and Selected Topics in Power Electronics, Vol. 6, No. 4, pp. 1892-1902, 2018,  https://doi.org/10.1109/JESTPE.2017.2773138 .
[6] Xiong, J., Ye, Y., Wang, Q., Dong, X., Lu, T., Ma, D., "A comprehensive review on distributed energy cooperative control and optimization method for energy interconnection system", Electric Power Systems Research, Vol. 237, p. 111007, 2024,  https://doi.org/10.1016/j.epsr.2024.111007.
[7] Yang, T., Lai, J., Yu, C., Wang, X., Xiao, Q., "Distributed two-layer predictive control of ac microgrid clusters with communication delays", IEEE Transactions on Smart Grid, pp. 1-1, 2025,  https://doi.org/10.1109/TSG.2025.3539789.
[8] Satapathy, A. S., Mohanty, S., Mohanty, A., Rajamony, R. K., M Soudagar, M. E., Khan, T. M. Y., Kalam, M. A., Ali, M. M., Bashir, M. N., "Emerging technologies, opportunities and challenges for microgrid stability and control", Energy Reports, Vol. 11, pp. 3562-3580, 2024,  https://doi.org/10.1016/j.egyr.2024.03.026.
[9] Feng, J., Bai, F., Nadarajah, M., Ma, H., Pradana, A., "Virtual inertia control for damping low-frequency oscillation in IBR-Dominated networks", IEEE Transactions on Industry Applications, pp. 1-10, 2025,  https://doi.org/10.1109/TIA.2025.3532239
[10]  Zhang, Y., Xie, L., Ding, Q., "Interactive control of coupled microgrids for guaranteed system-wide small signal stability", IEEE Transactions on Smart Grid, Vol. 7, No. 2, pp. 1088-1096, 2016,  https://doi.org/10.1109/TSG.2015.2495233
[11]  Hassan, C. T., Mahmood Jadoon, T., Arif, A., "Delay-dependent small-signal stability analysis of inverter-based islanded microgrids", IET Smart Grid, Vol. 8, No. 1, p. e12206, 2025,  https://doi.org/10.1049/stg2.12206.
[12]  Matas-Díaz, F. J., Barragán-Villarejo, M., Maza-Ortega, J. M., "A systematic small-signal analysis procedure for improving synchronization stability of grid-forming virtual synchronous generators", Journal of Modern Power Systems and Clean Energy, Vol. 13, No. 1, pp. 102-114, 2025,  https://doi.org/10.35833/MPCE.2024.000316
[13]  AbdelAty, A. M., Al-Durra, A., Zeineldin, H., El-Saadany, E. F., "Improving small-signal stability of inverter-based microgrids using fractional-order control", International Journal of Electrical Power & Energy Systems, Vol. 156, p. 109746, 2024,  https://doi.org/10.1016/j.ijepes.2023.109746.
[14]  Khosravi, N., Baghbanzadeh, R., Oubelaid, A., Tostado-Véliz, M., Bajaj, M., Hekss, Z., Echalih, S., Belkhier, Y., Houran, M. A., Aboras, K. M., "A novel control approach to improve the stability of hybrid AC/DC microgrids", Applied Energy, Vol. 344, p. 121261, 2023,  https://doi.org/10.1016/j.apenergy.2023.121261.
[15]  Wu, X., Xu, Y., Wu, X., He, J., Guerrero, J. M., Liu, C. C., Schneider, K. P., Ton, D. T., "A two-layer distributed cooperative control method for islanded networked microgrid systems", IEEE Transactions on Smart Grid, Vol. 11, No. 2, pp. 942-957, 2020,  https://doi.org/10.1109/TSG.2019.2928330
[16]  Yao, W., Wang, Y., Xu, Y., Lin, P., Qi, Y., Wu, Q., "Distributed layered control and stability analysis of islanded networked-microgrids", International Journal of Electrical Power & Energy Systems, Vol. 129, p. 106889, 2021,  https://doi.org/10.1016/j.ijepes.2021.106889.
[17]  He, J., Wu, X., Wu, X., Xu, Y., Guerrero, J. M., "Small-Signal stability analysis and optimal parameters design of microgrid clusters", IEEE Access, Vol. 7, pp. 36896-36909, 2019,  https://doi.org/10.1109/ACCESS.2019.2900728
[18]  Pogaku, N., Prodanovic, M., Green, T. C., "Modeling, analysis and testing of autonomous operation of an inverter-based microgrid", IEEE Transactions on Power Electronics, Vol. 22, No. 2, pp. 613-625, 2007,  https://doi.org/10.1109/TIE.2016.2577542
[19]  Zhao, Z., Yang, P., Wang, Y., Xu, Z., Guerrero, J. M., "Dynamic characteristics analysis and stabilization of pv-based multiple microgrid clusters", IEEE Transactions on Smart Grid, Vol. 10, No. 1, pp. 805-818, 2019,  https://doi.org/10.1109/TSG.2017.2752640
[20]  Liaqat, M., Alsuwian, T., Amin, A. A., Adnan, M., Zulfiqar, A., "Transient stability enhancement in renewable energy integrated multi-microgrids: A comprehensive and critical analysis", Measurement and Control, Vol. 57, No. 2, pp. 187-207, 2024/02/01 2023,  https://doi.org/10.1177/00202940231196193
[21]  Mohammadi, F. D., Vanashi, H. K., Feliachi, A., "State-Space modeling, analysis, and distributed secondary frequency control of isolated microgrids", IEEE Transactions on Energy Conversion, Vol. 33, No. 1, pp. 155-165, 2018,  https://doi.org/10.1109/TEC.2017.2757012
[22]  P, E. S. N. R., Jain, T., "A two-level hierarchical controller to enhance stability and dynamic performance of islanded inverter-based microgrids with static and dynamic loads", IEEE Transactions on Industrial Informatics, Vol. 15, No. 5, pp. 2786-2797, 2019,  https://doi.org/10.1109/TII.2018.2869983
[23]  Wu, X., Zhang, L., Xu, Y., Wang, S., Guerrero, J. M., "Hierarchical and distributed control of AC and DC microgrid clusters interconnected by flexible DC distribution network", CSEE Journal of Power and Energy Systems, pp. 1-12, 2025,  https://doi.org/10.17775/CSEEJPES.2024.01190
[24] Nguyen, T. L., Wang, Y., Tran, Q. T., Caire, R., Xu, Y., Gavriluta, C., "A distributed hierarchical control framework in islanded microgrids and its agent-based design for cyber-physical implementations", IEEE Transactions on Industrial Electronics, pp. 1-1, 2020,  https://doi.org/10.1109/TIE.2020.3026267
[25]  Mohammadi, F., Mohammadi-Ivatloo, B., Gharehpetian, G. B., Ali, M. H., Wei, W., Erdinç, O., Shirkhani, M., "Robust control strategies for microgrids: a review", IEEE Systems Journal, Vol. 16, No. 2, pp. 2401-2412, 2022,  https://doi.org/10.1109/JSYST.2021.3077213
[26]  Zuo, S., Davoudi, A., Song, Y., Lewis, F. L., "Distributed finite-time voltage and frequency restoration in islanded AC microgrids", IEEE Transactions on Industrial Electronics, Vol. 63, No. 10, pp. 5988-5997, 2016,  http://doi.org/10.1109/TIE.2016.2577542.