Maintaining and Improving Voltage and Frequency Stability in AC Microgrid Using Adaptive Load Shedding and Battery Storage

Document Type : Research Paper

Authors

Department of Electrical Engineering, Shahid Chamran University, Ahvaz, Khuzestan, Iran.

Abstract

In recent years, due to economic, technical, and environmental limitations, the expansion of microgrids and their integration with the main distribution network has become an effective solution for optimal use of the power grid. This paper used a hierarchical control strategy in the first and second layers to deal with slight and heavy disturbances that occurred in the islanding mode of operation. The first level is responsible for power sharing using the droop control method, and the second level is tasked with restoring frequency and voltage stability in the case of large disturbances that may lead to collapse and blackout in a microgrid. In this paper, using an energy storage system(battery) and a static synchronous compensator, the stability of important variables of the microgrid is maintained and improved when a small-scale disturbance occurs in the islanding mode of operation. This paper proposes a new adaptive load shedding method with inertia update to maintain frequency stability during large-scale power imbalance. Loads with lower priority are shed, and important variables of the network, i.e., voltage and frequency, are returned to their nominal value. The results show that the control structure in different conditions may maintain the frequency and voltage in the nominal range of the microgrid. The simulations are carried out in MATLAB software.
 

Keywords

Main Subjects


[1]           K. Twaisan and N. Barışçı, "Integrated distributed energy resources (DER) and microgrids: Modeling and optimization of DERs," Electronics, vol. 11, no. 18, p. 2816, 2022.
[2]           M. Mohebbi-Gharavanlou, S. Nojavan, and K. Zareh, "Energy management of virtual power plant to participate in the electricity market using robust optimization," Journal of Operation and Automation in Power Engineering, vol. 8, no. 1, pp. 43-56, 2020.
[3]           S. Ali, Z. Zheng, M. Aillerie, J.-P. Sawicki, M.-C. Pera, and D. Hissel, "A review of DC Microgrid energy management systems dedicated to residential applications," Energies, vol. 14, no. 14, p. 4308, 2021.
[4]           G. Chen, F. L. Lewis, E. N. Feng, and Y. Song, "Distributed optimal active power control of multiple generation systems," IEEE Transactions on Industrial Electronics, vol. 62, no. 11, pp. 7079-7090, 2015.
[5]           R. Khan et al., "Energy sustainability–survey on technology and control of microgrid, smart grid and virtual power plant," IEEE Access, vol. 9, pp. 104663-104694, 2021.
[6]           P. Venkata, V. Pandya, and A. Sant, "Data Mining Model Based Differential Microgrid Fault Classification Using SVM‎ Considering Voltage and Current Distortions," Journal of Operation and Automation in Power Engineering, vol. 11, no. 3, pp. 162-172, 2023.
[7]           A. Fathi, Q. Shafiee, and H. Bevrani, "Robust frequency control of microgrids using an extended virtual synchronous generator," IEEE Transactions on Power Systems, vol. 33, no. 6, pp. 6289-6297, 2018.
[8]           K. Y. Yap, C. R. Sarimuthu, and J. M.-Y. Lim, "Virtual inertia-based inverters for mitigating frequency instability in grid-connected renewable energy system: A review," Applied Sciences, vol. 9, no. 24, p. 5300, 2019.
[9]           K. C. Divya and J. Østergaard, "Battery energy storage technology for power systems—An overview," Electric power systems research, vol. 79, no. 4, pp. 511-520, 2009.
[10]         X. Tan, Q. Li, and H. Wang, "Advances and trends of energy storage technology in microgrid," International Journal of Electrical Power & Energy Systems, vol. 44, no. 1, pp. 179-191, 2013.
[11]         T. Madiba, R. Bansal, N. Mbungu, M. Bettayeb, R. Naidoo, and M. Siti, "Under-frequency load shedding of microgrid systems: a review," International Journal of Modelling and Simulation, vol. 42, no. 4, pp. 653-679, 2022.
[12]         J. Singh, S. Prakash Singh, K. Shanker Verma, A. Iqbal, and B. Kumar, "Recent control techniques and management of AC microgrids: A critical review on issues, strategies, and future trends," International Transactions on Electrical Energy Systems, vol. 31, no. 11, p. e13035, 2021.
[13]         S. K. Jha, D. Kumar, and M. Lehtonen, "Modified VI droop-based adaptive vector control scheme for demand side management in a stand-alone microgrid," International Journal of Electrical Power & Energy Systems, vol. 130, p. 106950, 2021.
[14]         M. Azimian, V. Amir, R. Habibifar, and H. Golmohamadi, "Probabilistic optimization of networked multi-carrier microgrids to enhance resilience leveraging demand response programs," Sustainability, vol. 13, no. 11, p. 5792, 2021.
[15]         Y. Liu, H. Wang, and C. Hou, "Sliding-mode control design for nonlinear systems using probability density function shaping," IEEE transactions on neural networks and learning systems, vol. 25, no. 2, pp. 332-343, 2013.
[16]         I. Kumarswamy, T. K. Sandipamu, and V. Prasanth, "Analysis of islanding detection in distributed generation using fuzzy logic technique," in 2013 7th Asia Modelling Symposium, 2013: IEEE, pp. 3-7.
[17]         M. N. Acosta et al., "Improvement of the frequency response indicators by optimal UFLS scheme settings," in 2020 IEEE 29th International Symposium on Industrial Electronics (ISIE), 2020: IEEE, pp. 1250-1255.
[18]         L. Sigrist, L. Rouco, and F. M. Echavarren, "A review of the state of the art of UFLS schemes for isolated power systems," International Journal of Electrical Power & Energy Systems, vol. 99, pp. 525-539, 2018.
[19]         P. Lakra and M. Kirar, "Load shedding techniques for systems with cogeneration: A review," Electrical and Electronics Engineering: An International Journal (ELELIJ) Vol, vol. 4, 2015.
[20]         M. Zadehbagheri, M. Kiani, and S. Khandan, "Designing a Robust SMC for Voltage and Power Control in Islanded Micro-grid and Simultaneous Use of Load Shedding Method," Journal of Operation and Automation in Power Engineering, vol. 13, no. 1, pp. 74-87, 2025.
[21]         H. Seyedi and M. Sanaye-Pasand, "New centralised adaptive load-shedding algorithms to mitigate power system blackouts," IET generation, transmission & distribution, vol. 3, no. 1, pp. 99-114, 2009.
[22]         U. Rudez and R. Mihalic, "A novel approach to underfrequency load shedding," Electric Power Systems Research, vol. 81, no. 2, pp. 636-643, 2011.
[23]         D. Bai, J. He, X. Yang, B. Kirby, D. Writer, and L. Liu, "Under frequency load shedding scheme based on information sharing technology," in 22nd International Conference and Exhibition on Electricity Distribution (CIRED 2013), 2013: IET, p. 0468.
[24]         K. Mollah and N. C. Nair, "Coordinated strategy for under-voltage and under-frequency load shedding," in 2010 20th Australasian Universities Power Engineering Conference, 2010: IEEE, pp. 1-6.
[25]         U. Rudez and R. Mihalic, "WAMS-based underfrequency load shedding with short-term frequency prediction," IEEE Transactions on Power Delivery, vol. 31, no. 4, pp. 1912-1920, 2015.
[26]         B. Hoseinzadeh and C. L. Bak, "Centralized coordination of emergency control and protection system using online outage sensitivity index," Electric Power Systems Research, vol. 163, pp. 413-422, 2018.
[27]         T. Shekari, A. Gholami, F. Aminifar, and M. Sanaye-Pasand, "An adaptive wide-area load shedding scheme incorporating power system real-time limitations," IEEE Systems Journal, vol. 12, no. 1, pp. 759-767, 2016.
[28]         B. Hoseinzadeh, F. M. F. Da Silva, and C. L. Bak, "Adaptive tuning of frequency thresholds using voltage drop data in decentralized load shedding," IEEE Transactions on Power Systems, vol. 30, no. 4, pp. 2055-2062, 2014.
[29]         B. Hoseinzadeh, F. F. da Silva, and C. L. Bak, "Decentralized coordination of load shedding and plant protection considering high share of RESs," IEEE Transactions on Power Systems, vol. 31, no. 5, pp. 3607-3615, 2015.
[30]         P. Mahat, Z. Chen, and B. Bak-Jensen, "Underfrequency load shedding for an islanded distribution system with distributed generators," IEEE Transactions on Power Delivery, vol. 25, no. 2, pp. 911-918, 2009.
[31]         W. Gu et al., "Adaptive decentralized under-frequency load shedding for islanded smart distribution networks," IEEE Transactions on Sustainable Energy, vol. 5, no. 3, pp. 886-895, 2014.
[32]         W. Liu et al., "Improved average consensus algorithm based distributed cost optimization for loading shedding of autonomous microgrids," International Journal of Electrical Power & Energy Systems, vol. 73, pp. 89-96, 2015.
[33]         M. Marzband, M. M. Moghaddam, M. F. Akorede, and G. Khomeyrani, "Adaptive load shedding scheme for frequency stability enhancement in microgrids," Electric Power Systems Research, vol. 140, pp. 78-86, 2016.
[34]         M. Karimi, P. Wall, H. Mokhlis, and V. Terzija, "A new centralized adaptive underfrequency load shedding controller for microgrids based on a distribution state estimator," IEEE Transactions on Power Delivery, vol. 32, no. 1, pp. 370-380, 2016.
[35]         S. Chandak, P. Bhowmik, and P. K. Rout, "Load shedding strategy coordinated with storage device and D-STATCOM to enhance the microgrid stability," Protection and Control of Modern Power Systems, vol. 4, no. 3, pp. 1-19, 2019.
[36]         M. Rezaee, S. Mortazavi, and A. Saffarian, "Combination UFLS and UVLS Aim to Restore Frequency and Voltage Stability Simultaneously," in 2025 Fifth National and the First International Conference on Applied Research in Electrical Engineering (AREE), 2025: IEEE, pp. 1-7.
[37]         N. Pogaku, M. Prodanovic, and T. C. Green, "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.
[38]         S. Tabatabaee, H. R. Karshenas, A. Bakhshai, and P. Jain, "Investigation of droop characteristics and X/R ratio on small-signal stability of autonomous microgrid," in 2011 2nd Power Electronics, Drive Systems and Technologies Conference, 2011: IEEE, pp. 223-228.
[39]         A. Mehrizi-Sani and R. Iravani, "Potential-function based control of a microgrid in islanded and grid-connected modes," IEEE Transactions on Power Systems, vol. 25, no. 4, pp. 1883-1891, 2010.
[40]         J. M. Guerrero, J. C. Vasquez, J. Matas, L. G. De Vicuña, and M. Castilla, "Hierarchical control of droop-controlled AC and DC microgrids—A general approach toward standardization," IEEE Transactions on Industrial Electronics, vol. 58, no. 1, pp. 158-172, 2010.
[41]         M. C. Chandorkar, D. M. Divan, and R. Adapa, "Control of parallel connected inverters in standalone AC supply systems," IEEE transactions on industry applications, vol. 29, no. 1, pp. 136-143, 2002.
[42]         P. M. Anderson and M. Mirheydar, "An adaptive method for setting underfrequency load shedding relays," IEEE Transactions on Power Systems, vol. 7, no. 2, pp. 647-655, 1992.
[43]         Y. Bo, X. Da, C. Chen, G. Fang, and L. Xiaobo, "Current status of low frequency load shedding in power system and its application," East China Electric Power, vol. 9, pp. 14-18, 2002.
[44]         V. V. Terzija, "Adaptive underfrequency load shedding based on the magnitude of the disturbance estimation," IEEE Transactions on Power Systems, vol. 21, no. 3, pp. 1260-1266, 2006.
[45]         S.-J. Huang and C.-C. Huang, "An adaptive load shedding method with time-based design for isolated power systems," International Journal of Electrical Power & Energy Systems, vol. 22, no. 1, pp. 51-58, 2000.
[46]         C. Li et al., "Continuous under-frequency load shedding scheme for power system adaptive frequency control," IEEE Transactions on Power Systems, vol. 35, no. 2, pp. 950-961, 2019.
[47]         E. Dehghanpour, H. K. Karegar, and R. Kheirollahi, "Under frequency load shedding in inverter-based microgrids by using droop characteristic," IEEE Transactions on Power Delivery, vol. 36, no. 2, pp. 1097-1106, 2020.
[48]         S. M. S. Kalajahi, H. Seyedi, and K. Zare, "Under-frequency load shedding in isolated multi-microgrids," Sustainable Energy, Grids and Networks, vol. 27, p. 100494, 2021.
[49]         C. Luo, H. G. Far, H. Banakar, P.-K. Keung, and B.-T. Ooi, "Estimation of wind penetration as limited by frequency deviation," in 2006 IEEE Power Engineering Society General Meeting, 2006: IEEE, p. 8 pp.
[50]         A. Ketabi and M. H. Fini, "An underfrequency load shedding scheme for islanded microgrids," International Journal of Electrical Power & Energy Systems, vol. 62, pp. 599-607, 2014.
[51]         N. T. Mbungu, R. Naidoo, R. C. Bansal, and M. Bipath, "Optimisation of grid connected hybrid photovoltaic–wind–battery system using model predictive control design," IET Renewable Power Generation, vol. 11, no. 14, pp. 1760-1768, 2017.
[52]         M. Khonji, C.-K. Chau, and K. Elbassioni, "Optimal power flow with inelastic demands for demand response in radial distribution networks," IEEE Transactions on Control of Network Systems, vol. 5, no. 1, pp. 513-524, 2016.
[53]         M. A. Allam, A. A. Hamad, M. Kazerani, and E. F. El-Saadany, "A novel dynamic power routing scheme to maximize loadability of islanded hybrid AC/DC microgrids under unbalanced AC loading," IEEE Transactions on Smart Grid, vol. 9, no. 6, pp. 5798-5809, 2017.
[54]         L. Gidwani, H. Tiwari, and R. Bansal, "Improving power quality of wind energy conversion system with unconventional power electronic interface," International Journal of Electrical Power & Energy Systems, vol. 44, no. 1, pp. 445-453, 2013.
[55]         M. Talaat, A. Hatata, A. S. Alsayyari, and A. Alblawi, "A smart load management system based on the grasshopper optimization algorithm using the under-frequency load shedding approach," Energy, vol. 190, p. 116423, 2020.
[56]         Y. Levron, J. M. Guerrero, and Y. Beck, "Optimal power flow in microgrids with energy storage," IEEE Transactions on Power Systems, vol. 28, no. 3, pp. 3226-3234, 2013.
[57]         Y. Dong, X. Xie, K. Wang, B. Zhou, and Q. Jiang, "An emergency-demand-response based under speed load shedding scheme to improve short-term voltage stability," IEEE Transactions on Power Systems, vol. 32, no. 5, pp. 3726-3735, 2017.
[58]         S. S. Reddy, "Multi-objective based congestion management using generation rescheduling and load shedding," IEEE Transactions on Power Systems, vol. 32, no. 2, pp. 852-863, 2016.
[59]         Q. Xu, B. Yang, Q. Han, Y. Yuan, C. Chen, and X. Guan, "Optimal power management for failure mode of MVDC microgrids in all-electric ships," IEEE Transactions on Power Systems, vol. 34, no. 2, pp. 1054-1067, 2018.