An Adaptive Method for Reducing Negative Sequence Voltage and Compensating Unbalance Voltage in Islanded Microgrids
Keywords: microgrid, distributed generation sources, unbalance voltage, negative sequence voltage, Central controller,
Abstract :
The voltage imbalance in microgrids leads to issues such as excessive temperature rise, reduced efficiency, and shortened lifespan of equipment and consumer devices. In this paper, a novel control method for compensating unbalance voltage in islanded microgrids is presented. This method adjusts the voltage reference of Distributed Generation (DG) units by adaptively estimating the negative sequence voltage drop across the feeder impedance of each phase, enabling effective compensation of voltage imbalance in the microgrid by reducing the negative sequence voltage. Unlike previous methods, this approach does not require a dedicated central controller and only relies on low-bandwidth communication (LBC) between neighboring DGs. Additionally, the method does not require precise information regarding the feeder impedance of the DGs' output. The process of determining and designing the control system parameters is fully explained, and to assess the performance of the proposed method, simulations are conducted on a test system using MATLAB/Simulink software. The simulation results demonstrate that this method can be an effective and efficient solution for compensating voltage imbalance in islanded microgrids
[1] F. Deng, X. Li, X. Zhang and P. Mattavelli, "An iterative virtual impedance regulation strategy in islanded microgrids for enhanced balanced unbalanced and harmonic current sharing", IEEE Trans. Sustain. Energy, vol. 13, no. 1, pp. 514-526, Jan. 2022. https://doi.org/10.1109/TSTE.2021.3118555.
[2] R. Jamalzadeh and M. Hong, "Microgrid optimal power flow using the generalized benders decomposition approach", IEEE Trans. Sustain. Energy, vol. 10, no. 4, pp. 2050-2064, Oct. 2019. https://doi.org/10.1109/TSTE.2018.2877907
[3] J. Lu, B. Zhang, X. Hou and J. M. Guerrero, "A Distributed Control Strategy for Unbalanced Voltage Compensation in Islanded AC Microgrids Without Continuous Communication," IEEE Transactions on Industrial Electronics, vol. 70, no. 3, pp. 2628-2638, March 2023. https://doi.org/10.1109/TIE.2022.3169841.
[4] J. Saroha, M. Singh and D. K. Jain, "ANFIS-Based Add-On Controller for Unbalance Voltage Compensation in a Low-Voltage Microgrid," in IEEE Transactions on Industrial Informatics, vol. 14, no. 12, pp. 5338-5345, Dec. 2018. https://doi.org/10.1109/TII.2018.2803748.
[5] H. Shi, F. Zhuo, H. Yi and Z. Geng, "Control strategy for microgrid under three-phase unbalance condition," Journal of Modern Power Systems and Clean Energy, vol. 4, no. 1, pp. 94-102, January 2016. https://doi.org/10.1007/s40565-015-0182-3.
[6] L. Meng, F. Tang, M. Savaghebi, J. C. Vasquez and J. M. Guerrero, "Tertiary Control of Voltage Unbalance Compensation for Optimal Power Quality in Islanded Microgrids," IEEE Transactions on Energy Conversion, vol. 29, no. 4, pp. 802-815, Dec. 2014. https://doi.org/10.1109/TEC.2014.2363687.
[7] Y. Han, P. Shen, X. Zhao and J. M. Guerrero, "An Enhanced Power Sharing Scheme for Voltage Unbalance and Harmonics Compensation in an Islanded AC Microgrid," IEEE Transactions on Energy Conversion, vol. 31, no. 3, pp. 1037-1050, Sept. 2016. https://doi.org/10.1109/TEC.2016.2552497.
[8] D. Yousri, H. E. Z. Farag, H. Zeineldin, A. Al-Durra and E. El-Saadany, "Per-Phase Unsymmetrical Adaptive Derivative Optimized Droop for Mitigating Voltage Quality Issues of Unbalanced Islanded Microgrids," IEEE Transactions on Sustainable Energy, vol. 15, no. 4, pp. 2518-2533, Oct. 2024. https://doi.org/10.1109/TSTE.2024.3424731.
[9] M. S. Golsorkhi, D. J. Hill and M. Baharizadeh, "A Secondary Control Method for Voltage Unbalance Compensation and Accurate Load Sharing in Networked Microgrids," IEEE Transactions on Smart Grid, vol. 12, no. 4, pp. 2822-2833, July 2021. https://doi.org/10.1109/TSG.2021.3062404.
[10] A. Borrell, M. Velasco, M. Castilla, J. Miret and R. Guzmán, "Collaborative Voltage Unbalance Compensation in Islanded AC Microgrids With Grid-Forming Inverters," IEEE Transactions on Power Electronics, vol. 37, no. 9, pp. 10499-10513, Sept. 2022. https://doi.org/10.1109/TPEL.2022.3169830.
[11] L. Meng et al., "Distributed Voltage Unbalance Compensation in Islanded Microgrids by Using a Dynamic Consensus Algorithm," IEEE Transactions on Power Electronics, vol. 31, no. 1, pp. 827-838, Jan. 2016. https://doi.org/10.1109/TPEL.2015.2408367.
[12] Shafiqurrahman, S. A. Yahyaee, P. Sreekumar and V. Khadkikar, "A Novel Decentralized Unbalance Load Sharing Approach for Islanded Microgrids," IEEE Transactions on Industry Applications, vol. 60, no. 4, pp. 5714-5725, July-Aug. 2024. https://doi.org/10.1109/TIA.2024.3384462.
[13] R. Kabiri, D. G. Holmes and B. P. McGrath, "Control of Active and Reactive Power Ripple to Mitigate Unbalanced Grid Voltages," IEEE Transactions on Industry Applications, vol. 52, no. 2, pp. 1660-1668, March-April 2016. https://doi.org/10.1109/TIA.2015.2508425.
[14] R. Nandi, M. Tripathy and C. P. Gupta, "Multi-Objective Optimization Based Voltage Injection Technique for Minimizing Imbalance and Harmonics in AC Microgrid," IEEE Transactions on Sustainable Energy, vol. 15, no. 2, pp. 1269-1287, April 2024. https://doi.org/10.1109/TSTE.2023.3336536.
[15] N. R. Merritt, C. Chakraborty and P. Bajpai, "New Voltage Control Strategies for VSC-Based DG Units in an Unbalanced Microgrid," IEEE Transactions on Sustainable Energy, vol. 8, no. 3, pp. 1127-1139, July 2017. https://doi.org/10.1109/TSTE.2017.2657660.
[16] J. Carlos Olives-Camps et al. "A systemic and model-less approach for real-time optimal control of unbalanced AC microgrids dominated by power electronics." International Journal of Electrical Power & Energy Systems, vol. 165, pp. 110443, 2025. https://doi.org/10.1016/j.ijepes.2024.110443.
[17] E. J. Smith, D. A. Robinson, & A. P. Agalgaonkar, A. P, "A secondary strategy for unbalance consensus in an islanded voltage source converter-based microgrid using cooperative gain control", Electric Power Systems Research, vol. 210, pp. 108097, 2022. https://doi.org/10.1016/j.epsr.2022.108097.
[18] M. M. Shahroudi, F. Faghihi, B. Mozafari, "A novel control scheme for load current components sharing improvement, and unbalanced and harmonic voltage compensation, in islanded provisional-microgrids", Electric Power Systems Research, vol. 223, pp. 109560, 2023. https://doi.org/10.1016/j.epsr.2023.109560.
[19] V. P. Suppioni, & A. Grilo-Pavani, "Unbalance compensation control in microgrids based on the unbalance profile", Electric Power Systems Research, vol. 196, pp. 107199, 2021. https://doi.org/10.1016/j.epsr.2021.107199.
[20] Y. Pavankumar, S. Debnath, & S. Paul, "Multi-objective pareto optimal unbalance voltage compensation in the microgrid", Electric Power Systems Research, vol. 217, pp. 109104, 2023. https://doi.org/10.1016/j.epsr.2022.109104
[21] H. Awad, H. M. Soliman, & E. H. Bayoumi,"Disturbance-rejection control for unbalanced operation of microgrids: Invariant-set approach," ISA transactions, vol. 153, pp. 334-349, 2024. https://doi.org/10.1016/j.isatra.2024.07.014.
[22] F. Nejabatkhah, Y. W. Li and B. Wu, "Control Strategies of Three-Phase Distributed Generation Inverters for Grid Unbalanced Voltage Compensation," IEEE Transactions on Power Electronics, vol. 31, no. 7, pp. 5228-5241, July 2016. https://doi.org/10.1109/TPEL.2015.2479601.
[23] J. Duarte, M. Velasco, P. Martí, A. Camacho and M. Castilla, "Robust Voltage Unbalance Control With Inherent Current Sharing in Grid-Connected Microgrids," in IEEE Transactions on Industrial Electronics, vol. 71, no. 12, pp. 16614-16624, Dec. 2024. https://doi.org/10.1109/TIE.2024.3398677.
[24] R. Ghanizdeh, and G. B. Gharehpetian, "Voltage quality and load sharing improvement in islanded microgrids using distributed hierarchical control," IET Renewable Power Generation, vol. 13, no. 15, pp. 2888-2898, Nov. 2019. https://doi.org/10.1049/iet-rpg.2019.0467.
[25] R. Ghanizdeh, and G. B. Gharehpetian, "Distributed hierarchical control structure for voltage harmonic compensation and harmonic current sharing in isolated MicroGrids," Sustainable Energy, Grids and Networks, vol. 16, pp. 55-69, Dec. 2018. https://doi.org/10.1016/j.segan.2018.05.005.
[26] J. M. Guerrero, J. Matas, L. Garcia de Vicuna, M. Castilla and J. Miret, "Decentralized Control for Parallel Operation of Distributed Generation Inverters Using Resistive Output Impedance," IEEE Transactions on Industrial Electronics, vol. 54, no. 2, pp. 994-1004, April 2007. https://doi.org/10.1109/TIE.2007.892621.
[27] E. Barklund, N. Pogaku, M. Prodanovic, C. Hernandez-Aramburo and T. C. Green, "Energy Management in Autonomous Microgrid Using Stability-Constrained Droop Control of Inverters," IEEE Transactions on Power Electronics, vol. 23, no. 5, pp. 2346-2352, Sept. 2008. https://doi.org/10.1109/TPEL.2008.2001910.
[28] M. Savaghebi, A. Jalilian, J. C. Vasquez and J. M. Guerrero, "Autonomous Voltage Unbalance Compensation in an Islanded Droop-Controlled Microgrid," IEEE Transactions on Industrial Electronics, vol. 60, no. 4, pp. 1390-1402, April 2013. https://doi.org/10.1109/TIE.2012.2185914.
[29] A. Ranjbaran, M. Ebadian, "A power sharing scheme for voltage unbalance and harmonics compensation in an islanded microgrid," Electric Power Systems Research, vol. 155, pp. 153-163, 2018. https://doi.org/10.1016/j.epsr.2017.09.026.