Control Design and Experimental Validation of a Scalable Single-Phase Islanded AC Microgrid Testbed for Research and Education
Main Article Content
Abstract
This paper presents a research and educational tool for islanded AC microgrids. High penetration of renewable energy can cause instability in traditional power grids. Microgrid technology addresses this by effectively integrating local renewable sources, managing energy through intelligent coordination, and can support the main power grid. However, obtaining test beds for research and education remains challenging due to system complexity, cost, and limited scalability in existing solutions. In this paper, the hierarchical control design of an islanded AC microgrid, which includes inner loop Proportional-Resonant controllers for voltage regulation, Phase-Locked Loop-based synchronization, virtual impedance for decoupling active and reactive powers, droop control for power sharing, and a secondary controller for voltage and frequency restoration as well as reactive power compensation is detailed. The experimental setup consists of two distributed generators (inverters) feeding linear and nonlinear loads. It is controlled by a dSPACE platform, with STMF4 Discovery microcontrollers generating Pulse-Width-Modulation signals to reduce the computational burden on dSPACE and facilitate scalability. Experimental results demonstrate that the testbed maintains stable operation under various load conditions, achieves proper power sharing, and restores the microgrid’s frequency and voltage to predefined levels. Its modular design supports future expansion for both research and teaching, enabling hands-on experimentation and analysis.
Article Details
Section
This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
-
Attribution — You must give appropriate credit, provide a link to the license, and indicate if changes were made. You may do so in any reasonable manner, but not in any way that suggests the licensor endorses you or your use.
-
ShareAlike — If you remix, transform, or build upon the material, you must distribute your contributions under the same license as the original.
- No additional restrictions — You may not apply legal terms or technological measures that legally restrict others from doing anything the license permits.
How to Cite
References
Buraimoh, E., Aluko, A. O., Oni, O. E., & Davidson, I. E. (2022). Decentralized virtual impedance-conventional droop control for power sharing for inverter-based distributed energy resources of a microgrid. Energies, 15(12), 4439. doi :10.3390/en15124439.
Chakraborty, S., Wang, J., Ganguly, S., & Kroposki, B. (2024). Development of a practical secondary control for hardware microgrids. IEEE Energy Conversion Congress and Exposition (ECCE), Phoenix, AZ, Doi :10.1109/ECCE55643.2024.10860894.
Daneshvar, M. R., Asadi, S., & Mohammadi-Ivatloo, B. (2021). Grid Modernization - Future Energy Network Infrastructure: Overview, Uncertainties, Modelling, Optimization, and Analysis. Power Systems series. Cham, Switzerland: Springer. ISBN 978-3-030-64098-9, DOI: 10.1007/978-3-030-64099-6.
de Souza, W. F., Severo Mendes, M. A., & Lopes, L. A. C. (2015). Power sharing control strategies for a three-phase microgrid in different operating conditions with droop control and damping factor investigation. IET Renewable Power Generation, 9(7), 831-839, doi:10.1049/iet-rpg.2014.0250.
Esmaeili Karkevandi, A., Daryani, M. J., & Usta, O. (2018). ANFIS-Based Intelligent PI Controller for Secondary Frequency and Voltage Control of Microgrid. 2018 IEEE PES Innovative Smart Grid Technologies Conference Europe (ISGT-Europe), Sarajevo, Bosnia and Herzegovina, doi:10.1109/ISGTEurope.2018.8571748.
Ferrari, M., Starke, M., Smith, J., Ollis, B., Sundararajan, A., & Garcia, Y. (2024). A Networked Microgrid Framework and Testbed for Communication, Controls, and Optimization Testing. 2024 IEEE Energy Conversion Congress and Exposition (ECCE), Phoenix, AZ, USA, doi:10.1109/ECCE55643.2024.10860879.
Govind, D., Suryawanshi, H. M., Nachankar, P., Narayana, C. L., & Singhal, A. (2023). A modified voltage controller with advanced droop control for load sharing in standalone AC microgrid under different load conditions. IEEE Transactions on Industry Applications, 59(5), 5818-5831, doi :10.1109/TIA.2023.3290931.
Guerrero, J. M., Vasquez, J. C., Matas, J., de Vicuna, L. G., & Castilla, M. (2011). Hierarchical control of droop-controlled AC and DC microgrids - A general approach toward standardization. IEEE Transactions on Industrial Electronics, 58(1), 158-172, doi :10.1109/TIE.2010.2066534.
Haidekker, M. A., Liu, M., & Song, W. (2023). Alternating-current microgrid testbed built with low-cost modular hardware. Sensors, 23(6), 3235, doi:10.3390/s23063235.
Han, Y., Luo, M., Zhao, X., Guerrero, J. M., & Xu, L. (2016). Comparative Performance Evaluation of Orthogonal-Signal-Generators-Based Single-Phase PLL Algorithms-A Survey. IEEE Transactions on Power Electronics, 31(5), 3932-3944, doi:10.1109/TPEL.2015.2466631.
He, J. J., Van Bossuyt, D. L., & Pollman, A. (2022). Experimental validation of systems engineering resilience models for islanded microgrids. Systems, 10(6), 245, doi:10.3390/systems10060245.
Hirsch, A., Parag, Y., & Guerrero, J. M. (2018). Microgrids: A review of technologies, key drivers, and outstanding issues. Renewable and Sustainable Energy Reviews, 90, 402-411, doi:10.1016/j.rser.2018.03.040.
John, B., Ghosh, A., & Zare, F. (2017). Droop control in low voltage islanded microgrids for sharing nonlinear and unbalanced loads. 2017 IEEE Region 10 Symposium (TENSYMP), Cochin, India, doi: 10.1109/TENCONSpring.2017.8069980.
Khayat, Y., Shafiee, Q., Heydari, R., Naderi, M., Dragicevic, T., Simpson-Porco, J. W., Dorfler, F., Fathi, M., Blaabjerg, F., Guerrero, J. M., & Bevrani, H. (2020). On the secondary control architectures of AC microgrids: An overview. IEEE Transactions on Power Electronics, 35(6), 6482-6500, doi:10.1109/TPEL.2019.2951694.
Lian, Z., Wen, C., Guo, F., Lin, P., & Wu, Q. (2023). Decentralized secondary control for frequency restoration and power allocation in islanded AC microgrids. International Journal of Electrical Power & Energy Systems, 148, doi:10.1016/j.ijepes.2022.108927.
Lidula, N. W. A., & Rajapakse, A. D. (2011). Microgrids research: A review of experimental microgrids and test systems. Renewable and Sustainable Energy Reviews, 15(1), 186-202, doi:10.1016/j.rser.2010.09.041.
Micallef, A., Apap, M., Spiteri Staines, C., Guerrero, J. M., & Vasquez, J. C. (2014). Reactive power sharing and voltage harmonic distortion compensation of droop controlled single phase islanded microgrids. IEEE Transactions on Smart Grid, 5(3), 1149-1158, doi: 10.1109/TSG.2013.2291912.
Mohammed, N., Lashab, A., Ciobotaru, M., & Guerrero, J. M. (2023). Accurate reactive power sharing strategy for droop-based islanded AC microgrids. IEEE Transactions on Industrial Electronics, 70(3), 2696-2707, doi:10.1109/TIE.2022.3167141.
Prasad, P. S., & Parimi, A. M. (2023). Design and analysis of decentralized virtual impedance based controller for enhancing power sharing and stability in an islanded microgrid. Journal of Electrical Engineering & Technology, 18(2), 1769-1783, doi:10.1007/s42835-022-01336-4.
Quizhpe, K., Arévalo, P., Ochoa-Correa, D., & Villa-Avila, E. (2024). Optimizing microgrid planning for renewable integration in power systems: A comprehensive review. Electronics, 13(18), 3620, doi:10.3390/electronics13183620.
Rodriguez, P., Luna, A., Candela, I., Mujal-Rosas, R., Teodorescu, R., & Blaabjerg, F. (2011). Multiresonant frequency-locked loop for grid synchronization of power converters under distorted grid conditions. IEEE Transactions on Industrial Electronics, 58(1), 127-138, doi:10.1109/TIE.2010.2042420.
Rodriguez, P., Luna, A., Munoz-Aguilar, R. S., Etxeberria-Otadui, I., Teodorescu, R., & Blaabjerg, F. (2012). A Stationary Reference Frame Grid Synchronization System for Three-Phase Grid-Connected Power Converters Under Adverse Grid Conditions. IEEE Transactions on Power Electronics, 27(1), 99-112, doi:10.1109/TPEL.2011.2159242.
Rodriguez-Martinez, O. F., Andrade, F., Vega Penagos, C. A., & Luna, A. C. (2023). A review of distributed secondary control architectures in islanded inverter-based microgrids. Energies, 16(2), 878. doi:10.3390/en16020878.
Shrivastava, S., & Subudhi, B. (2020). Comprehensive review on hierarchical control of cyber-physical microgrid system. IET Generation, Transmission & Distribution, 14(26), 6397-6416. doi:10.1049/iet-gtd.2020.0464, doi: 10.1049/iet-gtd.2020.0971.
Sreekumar, P., & Khadkikar, V. (2017). Direct control of the inverter impedance to achieve controllable harmonic sharing in the islanded microgrid. IEEE Transactions on Industrial Electronics, 64(1), 827-837. doi:10.1109/TIE.2016.2574308.
Uddin, M., Mo, H., Dong, D., Elsawah, S., Zhu, J., & Guerrero, J. M. (2023). Microgrids: A review, outstanding issues and future trends. Energy Strategy Reviews, 49, Article 101127, doi:10.1016/j.esr.2023.101127.
Vasquez, J. C., Guerrero, J. M., Savaghebi, M., Eloy Garcia, J., & Teodorescu, R. (2013). Modeling, analysis, and design of stationary reference frame droop controlled parallel three-phase voltage source inverters. IEEE Transactions on Industrial Electronics, 60(4), 1271-1280. doi:10.1109/TIE.2012.2194951.
Wang, L., Li, T., Cheng, Z., Hu, X., Li, Z., Liu, Z., Huang, J., & Hou, X. (2023). A unified droop control of AC microgrids under different line impedances: Revisiting droop control and virtual impedance method. Frontiers in Energy Research, 11, 1190833, doi:10.3389/fenrg.2023.1190833.
Wang, R., Hsu, S.-C., Zheng, S., Chen, J.-H., & Li, X. I. (2020). Renewable energy microgrids: Economic evaluation and decision making for government policies to contribute to affordable and clean energy. Applied Energy, 274, 115287, doi:10.1016/j.apenergy.2020.115287.
Wang, R., Zhao, X., Sun, Q., Xiao, J., Zhang, L., & Wang, P. (2023). Stability Analysis of Phase Locked Loops for AC Microgrids With Hybrid Power Sources. IEEE Transactions on Energy Conversion, 38(2), 1197-1207, doi:10.1109/TEC.2022.3224015.
Wu, D., Dragicevic, T., Vasquez, J. C., Guerrero, J. M., & Guan, Y. (2014). Secondary coordinated control of islanded microgrids based on consensus algorithms. IEEE Energy Conversion Congress and Exposition (ECCE), Pittsburgh, PA, USA, 4290–4297, doi:10.1109/ECCE.2014.6953986.
Xu, J., & Xie, S. (2018). LCL-resonance damping strategies for grid-connected inverters with LCL filters: A comprehensive review. Journal of Modern Power Systems and Clean Energy, 6(2), 292–305, doi: 10.1007/s40565-017-0319-7.
Yang, Y., & Blaabjerg, F. (2013). A new power calculation method for single-phase grid-connected systems. 2013 IEEE International Symposium on Industrial Electronics, Taipei, Taiwan, doi:10.1109/ISIE.2013.6563684.
Yao, W., Yang, Y., Zhang, X., Blaabjerg, F., & Loh, P. C. (2017). Design and analysis of robust active damping for LCL filters using digital notch filters. IEEE Transactions on Power Electronics, 32(3), 2360–2375, doi: 10.1109/ISIE.2013.6563684.