Design and Analysis of LCL-type Grid-Connected PV Power Conditioning System Based on Positive Virtual Impedance Capacitor-Current Feedback Active Damping
Document Type : Original Article
Authors
Department of Electrical Engineering, University of Mohaghegh Ardabili, Ardabil, Iran
10.22059/jser.2023.357089.1286
Abstract
In recent years, grid-connected solar systems have become increasingly common on low-voltage grids to promote renewable energy sources. In these systems, LCL filters are commonly used to eliminate high-frequency harmonics produced by switching grid-connected inverters. However, the resonance frequency of LCL filters is highly dependent on network impedance. Variations in network impedance can shift the resonance frequency, causing instability in the system. To address this issue, this paper proposes a new method for attenuating resonance using capacitor-current feedback with positive virtual impedance shaping. It can provide a positive equivalent resistance almost within the Nyquist frequency, i.e., the entire controllable frequency range. The proposed method maintains system stability against changes in network impedance and offers good performance against changes in the production capacity of the solar array. For maximum power point tracking, the incremental conductance method and integral regulator are used. Simulation results using MATLAB/Simulink software demonstrate the effectiveness of the proposed method in injecting high-quality current into the network and maintaining stability against changes in network impedance. The proposed method can lead to improved power quality and increased efficiency of grid-connected solar systems, which can help to promote the adoption of renewable energy sources and reduce carbon emissions.
Keywords
[1] Navesi, R. B., Nazarpour, D., Ghanizadeh, R., & Alemi, P. (2021). Switchable capacitor bank coordination and dynamic network reconfiguration for improving operation of distribution network integrated with renewable energy resources. Journal of modern power systems and clean energy, 10(3), 637-646.
[2] Srivastava, A., & Seshadrinath, J. (2022). A New Nine Level Highly Efficient Boost Inverter for Transformerless Grid Connected PV Application. IEEE Journal of Emerging and Selected Topics in Power Electronics.
[3] Manoharan, P., Subramaniam, U., Babu, T. S., Padmanaban, S., Holm-Nielsen, J. B., Mitolo, M., & Ravichandran, S. (2020). Improved perturb and observation maximum power point tracking technique for solar photovoltaic power generation systems. IEEE Systems Journal, 15(2), 3024-3035.
[4] Bhattacharyya, S., Samanta, S., & Mishra, S. (2020). Steady output and fast tracking MPPT (SOFT-MPPT) for P&O and InC algorithms. IEEE Transactions on Sustainable Energy, 12(1), 293-302.
[5] Rasekh, N., & Hosseinpour, M. (2020). Adequate tuning of LCL filter for robust performance of converter side current feedback control of grid connected modified–Y-source inverter. International Journal of Industrial Electronics Control and Optimization, 3(3), 365-378.
[6] Huang, M., Zhang, Z., Wu, W., & Yao, Z. (2022). An improved three-level cascaded control for LCL-filtered grid-connected inverter in complex grid impedance condition. IEEE Access, 10, 65485-65495.
[7] Bonaldo, J. P., de Arimatéia Olímpio Filho, J., dos Santos Alonso, A. M., Paredes, H. K. M., & Marafão, F. P. (2021). Modeling and control of a single-phase grid-connected inverter with lcl filter. IEEE Latin America Transactions, 19(02), 250-259.
[8] Mazaheri, A., Barati, F., & Jamil, M. (2019). A Simulation-Aided LCL Filter Design for Grid-Interactive Three-Phase Photovoltaic Inverters. Journal of Solar Energy Research, 4(4), 229-236.
[9] Ding, X., Xue, R., Zheng, T., Kong, F., & Chen, Y. (2022). Robust Delay Compensation Strategy for LCL-Type Grid-Connected Inverter in Weak Grid. IEEE Access, 10, 67639-67652.
[10] Nazib, A. A., Holmes, D. G., & McGrath, B. P. (2021). Self-synchronizing stationary frame inverter-current-feedback control for LCL grid-connected inverters. IEEE Journal of Emerging and Selected Topics in Power Electronics, 10(2), 1434-1446.
[11] Khan, D., Zhu, K., Hu, P., Waseem, M., Ahmed, E. M., & Lin, Z. (2023). Active damping of LCL-Filtered Grid-Connected inverter based on parallel feedforward compensation strategy. Ain Shams Engineering Journal, 14(3), 101902.
[12] Hosseinpour, M., & Rasekh, N. (2019). A single-phase grid-tied PV based trans-z-source inverter utilizing LCL filter and grid side current active damping. Journal of Energy Management and Technology, 3(3), 67-77.
[13] 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.
[14] Kouchaki, A., & Nymand, M. (2018). Analytical design of passive LCL filter for three-phase two-level power factor correction rectifiers. IEEE Transactions on power electronics, 33(4), 3012-3022.
[15] Bao, C., Ruan, X., Wang, X., Li, W., Pan, D., & Weng, K. (2014). Step-by-step controller design for LCL-type grid-connected inverter with capacitor–current-feedback active-damping. IEEE Transactions on Power Electronics, 29(3), 1239-1253.
[16] Xin, Z., Loh, P. C., Wang, X., Blaabjerg, F., & Tang, Y. (2016). Highly accurate derivatives for LCL-filtered grid converter with capacitor voltage active damping. IEEE Transactions on Power Electronics, 31(5), 3612-3625.
[17] Huang, M., Wang, X., Loh, P. C., & Blaabjerg, F. (2015). Active damping of LLCL-filter resonance based on LC-trap voltage or current feedback. IEEE Transactions on Power Electronics, 31(3), 2337-2346.
[18] Yang, X., Wu, G., Meng, Z., Wang, Y., Ji, L., Xue, H., & Bian, X. (2021). An improved capacitor voltage full feedforward control strategy for LCL‐type grid‐connected inverter based on control delay compensation. IET Power Electronics, 14(15), 2466-2477.
[19] Zhong, G. X., Wang, Z., Zhou, J., Li, J., & Su, Q. (2022). Coordinated control of active disturbance rejection and grid voltage feedforward for grid‐connected inverters. IET Power Electronics.
[20] Hosseinpour, M., Kholousi, A., & Poulad, A. (2022). A robust controller design procedure for LCL‐type grid‐tied proton exchange membrane fuel cell system in harmonics‐polluted network. Energy Science & Engineering, 10(10), 3798-3818.
[21] He, Y., Wang, X., Ruan, X., Pan, D., & Qin, K. (2021). Hybrid active damping combining capacitor current feedback and point of common coupling voltage feedforward for LCL-type grid-connected inverter. IEEE Transactions on Power Electronics, 36(2), 2373-2383.
[22] Li, X., Wu, X., Geng, Y., Yuan, X., Xia, C., & Zhang, X. (2014). Wide damping region for LCL-type grid-connected inverter with an improved capacitor-current-feedback method. IEEE Transactions on Power Electronics, 30(9), 5247-5259.
[23] Pan, D., Ruan, X., Bao, C., Li, W., & Wang, X. (2014). Capacitor-current-feedback active damping with reduced computation delay for improving robustness of LCL-type grid-connected inverter. IEEE Transactions on Power Electronics, 29(7), 3414-3427.
[24] Wang, X., Blaabjerg, F., & Loh, P. C. (2016). Grid-current-feedback active damping for LCL resonance in grid-connected voltage-source converters. IEEE Transactions on Power Electronics, 31(1), 213-223.
[25] Wang, X., Blaabjerg, F., & Loh, P. C. (2015). Virtual RC damping of LCL-filtered voltage source converters with extended selective harmonic compensation. IEEE Transactions on Power Electronics, 30(9), 4726-4737.
[26] Li, X., Wu, X., Geng, Y., Yuan, X., Xia, C., & Zhang, X. (2015). Wide damping region for LCL-type grid-connected inverter with an improved capacitor-current-feedback method. IEEE Transactions on Power Electronics, 30(9), 5247-5259.
[27] Chen, C., Xiong, J., Wan, Z., Lei, J., & Zhang, K. (2017). A time delay compensation method based on area equivalence for active damping of an LCL-type converter. IEEE Transactions on Power Electronics, 32(1), 762-772.
[28] Pan, D., Ruan, X., Bao, C., Li, W., & Wang, X. (2015). Optimized controller design for LCL-type grid-connected inverter to achieve high robustness against grid-impedance variation. IEEE Transactions on Industrial Electronics, 62(3), 1537-1547.
[29] Huang, Q., & Rajashekara, K. (2017, March). Virtual RLC active damping for grid-connected inverters with LCL filters. In 2017 IEEE Applied Power Electronics Conference and Exposition (APEC) (pp. 424-429).
[30] Zhao, T., Li, J., & Gao, N. (2022). Capacitor-Current-Feedback With Improved Delay Compensation for LCL-Type Grid-Connected Inverter to Achieve High Robustness in Weak Grid. IEEE Access, 10, 127956-127968.
[31] Hosseinpour, M., Asad, M., & Rasekh, N. (2021). A Step-by-Step Design Procedure of a Robust Control Design for Grid-Connected Inverter by LCL Filter in a Weak and Harmonically Distorted Grid. Iranian Journal of Science and Technology, Transactions of Electrical Engineering, 45(3), 843-859.
[32] Rasekh, N., Hosseinpour, M., Dejamkhooy, A., & Akbarimajd, A. (2021). Robust power conditioning system based on LCL-type quasi-Y-source inverter for grid connection of photovoltaic arrays. International Journal of Automation and Control, 15(6), 692-709.
[33] Li, X., Fang, J., Tang, Y., Wu, X., & Geng, Y. (2018). Capacitor-voltage feedforward with full delay compensation to improve weak grids adaptability of LCL-filtered grid-connected converters for distributed generation systems. IEEE Transactions on Power Electronics, 33(1), 749-764.
[34] J Yin, J., Duan, S., & Liu, B. (2013). Stability analysis of grid-connected inverter with LCL filter adopting a digital single-loop controller with inherent damping characteristic. IEEE Transactions on Industrial Informatics, 9(2), 1104-1112.
[35] Holmes, D. G., Lipo, T. A., Mcgrath, B. P., & Kong, W. Y. (2009). Optimized design of stationary frame three phase AC current regulators. IEEE transactions on power electronics, 24(11), 2417-2426.
[36] Pan, D., Ruan, X., Wang, X., Yu, H., & Xing, Z. (2017). Analysis and design of current control schemes for LCL-type grid-connected inverter based on a general mathematical model. IEEE Transactions on Power Electronics, 32(6), 4395-4410.
[37] Anowar, M. H., & Roy, P. (2019, February). A modified incremental conductance based photovoltaic MPPT charge controller. In 2019 International Conference on Electrical, Computer and Communication Engineering (ECCE) (pp. 1-5).
[38] Saidi, A., & Benachaiba, C. (2016, November). Comparison of IC and P&O algorithms in MPPT for grid connected PV module. In 2016 8th International Conference on Modelling, Identification and Control (ICMIC) (pp. 213-218).
[39] Faiz, M. T., Khan, M. M., Jianming, X., Ali, M., Habib, S., Hashmi, K., & Tang, H. (2019). Capacitor voltage damping based on parallel feedforward compensation method for lcl-filter grid-connected inverter. IEEE Transactions on Industry Applications, 56(1), 837-849.
[40] Bimarta, R., & Kim, K. H. (2020). A robust frequency-adaptive current control of a grid-connected inverter based on LMI-LQR under polytopic uncertainties. IEEE Access, 8, 28756-28773.
[41] Padmanaban, S., Priyadarshi, N., Bhaskar, M. S., Holm-Nielsen, J. B., Hossain, E., & Azam, F. (2019). A hybrid photovoltaic-fuel cell for grid integration with jaya-based maximum power point tracking: experimental performance evaluation. IEEE Access, 7, 82978-82990.
[42] Kim, Y. J., & Kim, H. (2019). Optimal design of LCL filter in grid‐connected inverters. IET Power Electronics, 12(7), 1774-1782.
[43] Dragičević, T., Zheng, C., Rodriguez, J., & Blaabjerg, F. (2019). Robust quasi-predictive control of $ LCL $-filtered grid converters. IEEE Transactions on Power Electronics, 35(2), 1934-1946.
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