A Direct Discrete-Time Output Feedback-based LS-RMRAC for Grid-tied Current Control Loop of a Static 3-Wire Converter under Unbalanced Grid Voltage Conditions


Robust Adaptive Control
Grid-tied converter
LCL filter

Como Citar

Evald, P. J. D. de O. (2022). A Direct Discrete-Time Output Feedback-based LS-RMRAC for Grid-tied Current Control Loop of a Static 3-Wire Converter under Unbalanced Grid Voltage Conditions. ForScience, 10(1), e00993. https://doi.org/10.29069/forscience.2022v10n1.e993


Nowadays, renewable energy generation is a worldwide tendency. These clean sources are generally tied to the grid by voltage-fed static converters. In this work, a direct discrete-time Output Feedback-based LS (Least Squares)-RMRAC (Robust Model Reference Adaptive Control) is proposed for grid-side current loop control of a static 3-wire converter connected to the grid through LCL filter. The proposed control method mitigates the LCL filter resonance,
rejects grid disturbances without needing Resonant Controllers implementation, and deals properly with grid uncertainties and parametric variations, being suitable for grids with unbalanced voltage conditions. Simulation results of proposed controller are presented.

Keywords: Robust Adaptive Control. Grid-tied converter. LCL filter.



AMAMRA, S.-A. et al. Multilevel inverter topology for renewable energy grid integration. IEEE Transactions on Industrial Electronics, IEEE, v. 64, n. 11, p. 8855–8866, 2016. Disponível em: <https://ieeexplore.ieee.org/document/7800995>.

CARDOSO, R. et al. Kalman filter based synchronisation methods. IET generation, transmission & distribution, IET, v. 2, n. 4, p. 542–555, 2008. Disponível em: <https://digital-library.theiet.org/content/journals/10.1049/iet-gtd_20070281>.

CRAMER, A. et al. Power grid simulation considering electric vehicles and renewable energy sources. In: IEEE. 2019 Fourteenth International Conference on Ecological Vehicles and Renewable Energies (EVER). 2019. p. 1–3. Disponível em: <https://ieeexplore.ieee.org/iel7/8798485/8813510/08813642.pdf>.

DANNEHL, J.; FUCHS, F. W.; THÃ~GERSEN, P. B. Pi state space current control of grid-connected pwm converters with lcl filters. IEEE Transactions on Power Electronics, IEEE, v. 25, n. 9, p. 2320–2330, 2010. Disponível em: <https://ieeexplore.ieee.org/document/5443587>.

DUESTERHOEFT, W.; SCHULZ, M. W.; CLARKE, E. Determination of instantaneous currents and voltages by means of alpha, beta, and zero components. Transactions of the American Institute of Electrical Engineers, IEEE, v. 70, n. 2, p. 1248–1255, 1951. Disponível em: <https://ieeexplore.ieee.org/document/5060554>.

ELSAYAD, N.; MORADISIZKOOHI, H.; MOHAMMED, O. A. Design and implementation of a new transformerless bidirectional dc–dc converter with wide conversion ratios. IEEE Transactions on Industrial Electronics, IEEE, v. 66, n. 9, p. 7067–7077, 2018. Disponível em: <https://ieeexplore.ieee.org/document/8517159>.

EVALD, P. J. D. d. O.; TAMBARA, R. V.; GRÜNDLING, H. A. A discrete-time robust mrac applied on grid-side current control of a grid-connected three-phase converter with lcl filter. ELECTRIMACS 2019: Selected Papers-Volume 1, Springer Nature, v. 615, p. 45, 2020. Disponível em: <https://link.springer.com/chapter/10.1007/978-3-030-37161-6_4>.

EVALD, P. J. D. O.; TAMBARA, R. V.; GRÜNDLING, H. A. A direct discrete-time reduced order robust model reference adaptative control for grid-tied power converters with lcl filter. Eletrônica de Potência, Associação Brasileira de Eletrônica de Potência, v. 25, n. 3, p. 361–372, 2020. Disponível em: <https://sobraep.org.br/site/uploads/2020/09/rvol25no03-16-0039-361-372.pdf>.

FANG, X. et al. Improved quasi-y-source dc-dc converter for renewable energy. CPSS Transactions on Power Electronics and Applications, CPSS, v. 4, n. 2, p. 163–170, 2019. Disponível em: <https://ieeexplore.ieee.org/iel7/7873541/8758247/08758255.pdf>.

FLORA, L. D.; GRÜNDLING, H. A. Design of a robust model reference adaptive voltage controller for an electrodynamic shaker. Eletrônica de Potência, v. 13, n. 3, p. 133–140, 2008. Disponível em: <https://sobraep.org.br/site/uploads/2018/06/rvol13no3p1.pdf>.

GAO, C. et al. Current multi-loop control strategy for grid-connected inverter with lcl filter. In: IEEE. 33rd Youth Academic Annual Conference of Chinese Association of Automation (YAC). 2018. p. 712–716. Disponível em: https://ieeexplore.ieee.org/document/8406464>.

IOANNOU, P.; TSAKALIS, K. A robust direct adaptive controller. IEEE Transactions on Automatic Control, IEEE, v. 31, n. 11, p. 1033–1043, 1986. Disponível em: <https://ieeexplore.ieee.org/iel5/9/24237/01104168.pdf>.

IOANNOU, P. A.; SUN, J. Robust adaptive control. [S.l.]: Courier Corporation, 2012.

ISLAM, M. R.; GUO, Y.; ZHU, J. A high-frequency link multilevel cascaded medium- voltage converter for direct grid integration of renewable energy systems. IEEE Transactions on Power Electronics, IEEE, v. 29, n. 8, p. 4167–4182, 2013. Disponível em: <https://ieeexplore.ieee.org/document/6661455>.

KHWAN-ON, S.; KONGKANJANA, K. The control of a multi-input boost converter for renewable energy system applications. In: IEEE. 2017 International Electrical Engineering Congress (iEECON). 2017. p. 1–4. Disponível em: <https://ieeexplore.ieee.org/document/8075782>.

LINDGREN, M.; SVENSSON, J. Control of a voltage-source converter connected to the grid through an lcl-filter-application to active filtering. In: IEEE. 29th Annual IEEE Power Electronics Specialists Conference (PESC). 1998. v. 1, p. 229–235. Disponível em: <https://ieeexplore.ieee.org/iel4/5671/15202/00701904>.

LIU, C. et al. Model predictive control of single phase grid-connected inverter with lc filter. In: IEEE. 2017 32nd Youth Academic Annual Conference of Chinese Association of Automation (YAC). [S.l.], 2017. p. 115–119.

MACCARI, L. A. et al. Lmi-based control for grid-connected converters with lcl filters under uncertain parameters. IEEE Transactions on Power Electronics, IEEE, v. 29, n. 7, p.3776–3785, 2013. Disponível em: <https://ieeexplore.ieee.org/document/6587559/>.

______. Robust optimal current control for grid-connected three-phase pulse-width modulated converters. IET Power Electronics, IET, v. 8, n. 8, p. 1490–1499, 2015. Disponível em: <https://onlinelibrary.wiley.com/doi/full/10.1049/iet-pel.2014.0787>.

MOHAMMADI, S. et al. Optimal robust control of lcl-type grid-connected voltage source inverters against grid impedance fluctuations. In: IEEE. 10th International Power Electronics, Drive Systems and Technologies Conference (PEDSTC). 2019. p. 504–508. Disponível em: <https://ieeexplore.ieee.org/document/8697514>.

NEHRIR, M. et al. A review of hybrid renewable/alternative energy systems for electric power generation: Configurations, control, and applications. IEEE Transactions on Sustainable Energy, IEEE, v. 2, n. 4, p. 392–403, 2011. Disponível em: <https://ieeexplore.ieee.org/document/5773511>.

PINHEIRO, H. et al. Modulação space vector para inversores alimentados em tensão: uma abordagem unificada. Sba: Controle & Automação Sociedade Brasileira de Automatica, SciELO Brasil, v. 16, n. 1, p. 13–24, 2005. Disponível em:


RAHBAR, K.; CHAI, C. C.; ZHANG, R. Energy cooperation optimization in microgrids with renewable energy integration. IEEE Transactions on Smart Grid, IEEE, v. 9, n. 2, p.1482–1493, 2016. Disponível em: <https://ieeexplore.ieee.org/document/7544637>.

TAMBARA, R. V. et al. A discrete-time robust adaptive controller applied to grid-connected converters with lcl filter. Journal of Control, Automation and Electrical Systems, Springer,v. 28, n. 3, p. 371–379, 2017. Disponível em: <https://link.springer.com/article/10.1007/s40313-017-0313-3>.

TEODORESCU, R.; LISERRE, M.; RODRÍGUEZ, P. Grid Converters for Photovoltaic and Wind Power Systems. Wiley & Sons – IEEE, 2011. Disponível em: <https://www.wiley.com/en-us/Grid+Converters+for+Photovoltaic+and+Wind+Power+Systems-p-9780470057513>.

TIWARI, S. K.; SINGH, B.; GOEL, P. K. Design and control of microgrid fed by renewable energy generating sources. IEEE Transactions on Industry Applications, IEEE, v. 54, n. 3, p. 2041–2050, 2018. Disponível em: <https://ieeexplore.ieee.org/document/8258886>.

Creative Commons License

Este trabalho está licensiado sob uma licença Creative Commons Attribution-NonCommercial 4.0 International License.

Copyright (c) 2022 Array