Hybrid AC/DC Microgrid with Bidirectional Power Flow

Author

U.B.Malkhandale, P.N.Gaurkar, Pranjal Kale, Riya Narnaware, Mayuri Maske, Ayush Bhorkar

Abstract

Hybrid AC/DC microgrids bring solar generation, battery storage and utility supply together, but fluctuating generation and load can leave either bus short of power. This paper describes a low-cost laboratory prototype that moves energy in both directions between an AC bus and a 12 V DC bus without a purpose-built interlinking converter. A 200 W transformer-based inverter carries energy from the battery to the AC side, while a 14 V, 1.2 A SMPS charger carries it from the AC side back into the battery. An ESP32 board reads isolated voltage (ZMPT101B), current (ACS712) and mains-presence signals, then drives a two-channel relay module according to a small set of rules, using a break-before-make delay of about 2 s so that the grid and inverter are never joined. A 16×2 I²C LCD and a buzzer report the active mode. Staged bench tests confirmed correct grid detection, automatic grid-to-inverter and inverter-to-grid changeover, and calibrated voltage sensing (grid sensitivity 500→561, inverter 271→606). The prototype is intended for teaching and demonstration, and the paper closes with a route toward a true closed-loop bidirectional converter.

Keywords

hybrid microgrid, bidirectional power flow, ESP32, inverter, SMPS charger, battery storage, break-before-make changeover, renewable energy.

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References

[1]R. H. Lasseter, “MicroGrids,” in Proc. IEEE Power Eng. Soc. Winter Meeting, New York, NY, USA, 2002, vol. 1, pp. 305–308.

[2]J. J. Justo, F. Mwasilu, J. Lee, and J.-W. Jung, “AC-microgrids versus DC-microgrids with distributed energy resources: A review,” Renew. Sustain. Energy Rev., vol. 24, pp. 387–405, Aug. 2013.

[3]N. Hatziargyriou, Ed., Microgrids: Architectures and Control. Chichester, U.K.: Wiley–IEEE Press, 2014.

[4]P. C. Loh, D. Li, Y. K. Chai, and F. Blaabjerg, “Autonomous operation of hybrid microgrid with AC and DC subgrids,” IEEE Trans. Power Electron., vol. 28, no. 5, pp. 2214–2223, May 2013.

[5]X. Liu, P. Wang, and P. C. Loh, “A hybrid AC/DC microgrid and its coordination control,” IEEE Trans. Smart Grid, vol. 2, no. 2, pp. 278–286, Jun. 2011.

[6]A. Eghtedarpour and E. Farjah, “Power control and management in a hybrid AC/DC microgrid,” IEEE Trans. Smart Grid, vol. 5, no. 3, pp. 1494–1505, May 2014.

[7]S. Saponara, R. Saletti, and L. Mihet-Popa, “Hybrid micro-grids exploiting renewable sources, battery energy storages, and bi-directional converters,” Appl. Sci., vol. 9, no. 22, Art. no. 4973, 2019.

[8]M. Y. A. Khan, H. Liu, Y. Zhang, and J. Wang, “Hybrid AC/DC microgrid: Systematic evaluation of interlinking converters, control strategies, and protection schemes: A review,” IEEE Access, 2024.

[9]V. S. Fiuza and T. R. Oliveira, “Interlinking converters for hybrid AC/DC microgrids: A systematic literature review,” IEEE Access, 2025.

[10]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 Trans. Ind. Electron., vol. 58, no. 1, pp. 158–172, Jan. 2011.

[11]T. Dragičević, X. Lu, J. C. Vasquez, and J. M. Guerrero, “DC microgrids—Part I: A review of control strategies and stabilization techniques,” IEEE Trans. Power Electron., vol. 31, no. 7, pp. 4876–4891, Jul. 2016.

[12]J. Rocabert, A. Luna, F. Blaabjerg, and P. Rodríguez, “Control of power converters in AC microgrids,” IEEE Trans. Power Electron., vol. 27, no. 11, pp. 4734–4749, Nov. 2012.

[13]L. Meng et al., “Microgrid supervisory controllers and energy management systems: A literature review,” Renew. Sustain. Energy Rev., vol. 60, pp. 1263–1273, Jul. 2016.

[14]F. Blaabjerg, R. Teodorescu, M. Liserre, and A. V. Timbus, “Overview of control and grid synchronization for distributed power generation systems,” IEEE Trans. Ind. Electron., vol. 53, no. 5, pp. 1398–1409, Oct. 2006.

[15]D. Linden and T. B. Reddy, Eds., Handbook of Batteries, 3rd ed. New York, NY, USA: McGraw-Hill, 2002.

[16]N. Mohan, T. M. Undeland, and W. P. Robbins, Power Electronics: Converters, Applications, and Design, 3rd ed. Hoboken, NJ, USA: Wiley, 2003.

[17]R. Teodorescu, M. Liserre, and P. Rodríguez, Grid Converters for Photovoltaic and Wind Power Systems. Chichester, U.K.: Wiley–IEEE Press, 2011.

[18]Espressif Systems, “ESP32 Series Datasheet,” Shanghai, China. [Online]. Available: https://www.espressif.com

[19]Espressif Systems, “ADC Calibration,” ESP-IDF Programming Guide. [Online]. Available: https://docs.espressif.com

[20]Allegro MicroSystems, “ACS712: Fully integrated, Hall effect-based linear current sensor IC with 2.1 kVRMS isolation and a low-resistance current conductor,” Datasheet.

[21]Texas Instruments, “LM2596 SIMPLE SWITCHER power converter 150-kHz 3-A step-down voltage regulator,” Datasheet.

[22]T. Esram and P. L. Chapman, “Comparison of photovoltaic array maximum power point tracking techniques,” IEEE Trans. Energy Convers., vol. 22, no. 2, pp. 439–449, Jun. 2007.

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