# Coordinated Bidirectional Power Flow Management with Power Quality Improvement in AC-DC Hybrid Micro-grid under Unbalanced Scenario

Keywords:
Bidirectional Interlinking Converter, Common Connecting Point, Hybrid Micro-Grid, Hysteresis Comparator Control, Shunt Active Power Filter

### Abstract

The present day electrical power system is highly complex due to the increase in load demand and distributed generations. Further, the intermittent renewable sources and non-linear power electronic loads connected to the grid deteriorates the power quality of the system. Also, the more and more DC loads like LED lights to save energy consumption are connected to the AC distribution system. These issues can be effectively addressed using the smart micro-grid system. In an individual AC or DC micro-grid, the higher number of AC-DC-AC/DC-AC-DC power conversion stages lead to the increased power losses. Therefore, in this paper, an AC-DC hybrid micro-grid topology is proposed, wherein, AC sources and AC loads are connected to AC grid while DC sources and DC loads are connected to DC grid there by reducing the power conversion losses. The shunt active power filter based 3-phase 4-leg bidirectional interlinking converter using d-q reference current method with PI control is proposed to accomplish the inverter-based & rectifier-based power exchange between AC & DC sub-grids with harmonic current compensation under various grid and load conditions. The analysis is carried out in MATLAB/SIMULINK and results proving the improved power quality.### References

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[2] P. García-triviño, A.J. Gil-mena, F. Llorens-iborra, C.A. García-vázquez, L.M. Fernández-ramírez, and F. Jurado, “Power control based on particle swarm optimization of grid-connected inverter for hybrid renewable energy system,” Energy Convers. Manag., Vol. 91, pp. 83–92, 2015.

[3] V. Rajasekaran, A. Merabet, H. Ibrahim, R. Beguenane, and J.S. Thongam, “Control System for Hybrid Wind Diesel Based Microgrid,” in Proc. 2013 IEEE Electrical Power & Energy Conf., pp. 1–6.

[4] W. Al-saedi, S.W. Lachowicz, D. Habibi, and O. Bass, “Power flow control in grid-connected microgrid operation using Particle Swarm Optimization under variable load conditions,” Electrical Power and Energy Systems, Vol. 49, pp. 76–85, 2013.

[5] S. Dasgupta, S. Member, S.N. Mohan, and S. Member, “Application of Four-Switch-Based Three-Phase Grid-Connected Inverter to Connect Renewable Energy Source to a Generalized Unbalanced Microgrid System,” IEEE Trans. Ind. Electron., Vol. 60, No. 3, pp. 1204–1215, 2013.

[6] A. Karabiber, C. Keles, A. Kaygusuz, and B.B. Alagoz, “An approach for the integration of renewable distributed generation in hybrid DC/AC microgrids,” Renew. Energy, Vol. 52, pp. 251–259, 2013.

[7] A. Khorsandi, M. Ashourloo, and H. Mokhtari, “A Decentralized Control Method for a Low-Voltage,” IEEE Trans. Energy Convers., Vol. 29, No. 4, pp. 793–801, 2014.

[8] M. Kumar, S.C. Srivastava, and S.N. Singh, “Control Strategies of a DC Microgrid for Grid Connected and Island Operations,” IEEE Trans. Smart Grid, Vol. 70, No. 4, pp. 635–655, 2015.

[9] K. Strunz, E. Abbasi, and D.N. Huu, “DC Microgrid for Wind and Solar Power Integration,” IEEE Journal of Emer. & Selected Topics in Power Electron., Vol. 2, No. 1, pp. 115–126, 2014.

[10] S. Anand, B.G. Fernandes, and J.M. Guerrero, “Distributed Control to Ensure Proportional Load Sharing and Improve Voltage Regulation in Low-Voltage DC Microgrids,” IEEE Trans. Power Electron., Vol. 28, No. 4, pp. 1900–1913, 2013.

[11] N. 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, 2014.

[12] X. Liu, P. Wang, and P.C. Loh, “A Hybrid AC/DC Micro-Grid and Its Coordination Control,” IEEE Trans. Smart Grid, Vol. 2, No. 2, pp. 746–751, 2011.

[13] P. Wang, L. Goel, X. Liu, F.H. Choo, and B.P. Wang, “Harmonizing AC and DC,” IEEE Power & Energy Mag, pp. 76–83, 2013.

[14] S. Pati, K. B. Mohanty, S. Kar, and A. Choudhury, “Integration and Power Control of a Micro-Hydro-PV- Wind based Hybrid Microgrid,” in Proc. 2017 Int. Conf. on Circuit, Power & Computing Technologies, pp. 1–6.

[15] F. Nejabatkhah and Y.W. Li, “Overview of Power Management Strategies of Hybrid AC & DC Microgrid,” IEEE Trans. Power Electron., Vol. 30, No. 12, pp. 7072–7089, 2015.

[16] E. Unamuno and J.A. Barrena, “Hybrid ac/dc microgrids — Part I : Review and classification of topologies,” Renew. Sustain. Energy Rev., Vol. 52, pp. 1251–1259, 2015.

[17] E. Unamuno and J.A. Barrena, “Hybrid ac/dc microgrids — Part II : Review and classification of control strategies,” Renew. Sustain. Energy Rev., Vol. 52, pp. 1123–1134, 2015.

[18] A. Gaillard, P. Poure, S. Saadate, and M. Machmoum, “Variable speed DFIG wind energy system for power generation and harmonic current mitigation,” Renew. Energy, Vol. 34, pp. 1545–1553, 2009.

[19] J. Hu, J. Zhu, and D.G. Dorrell, “Predictive Direct Power Control of Doubly Fed Induction Generators Under Unbalanced Grid Voltage Conditions for Power Quality Improvement,” IEEE Trans. Sustain. Energy, Vol. 6, No. 3, pp. 943–950, 2015.

[20] M. Boutoubat, L. Mokrani, and M. Machmoum, “Control of a wind energy conversion system equipped by a DFIG for active power generation and power quality improvement,” Renew. Energy, Vol. 50, pp. 378–386, 2013.

[21] C.-T. Hsu, R. Korimara, and T.-J. Cheng, “Power quality analysis for the distribution systems with a wind power generation system,” Comput. Electr. Eng, Vol. 54, pp. 131–136, 2015.

[22] M. Singh, V. Khadkikar, A. Chandra, and R. K. Varma, “Grid Interconnection of Renewable Energy Sources at the Distribution Level with Power-Quality Improvement Features,” IEEE Trans Power Electron, Vol. 26, No. 1, pp. 307–315, 2011.

[23] M. Mehrasa, E. Pouresmaeil, S. Zabihi, E. M. G. Rodrigues, and J. P. S. Catalão, “A control strategy for the stable operation of shunt active power filters in power grids,” Energy, Vol. 96, pp. 325–334, 2016.

[24] Q. N. Trinh and H. H. Lee, “An enhanced grid current compensator for grid-connected distributed generation under nonlinear loads and grid voltage distortions,” IEEE Trans. Ind. Electron., vol. 61, No. 12, pp. 6528–6537, 2014.

[25] E. Pouresmaeil, M. F. Akorede, D. Montesinos-Miracle, O. Gomis-Bellmunt, and J. C. Trujillo Caballero, “Hysteresis current control technique of VSI for compensation of grid-connected unbalanced loads,” Electr. Eng., Vol. 96, No. 1, pp. 27–35, 2014.

[26] J. He, Y. W. Li, F. Blaabjerg, and X. Wang, “Active Harmonic Filtering Using Current-Controlled, Grid-Connected DG Units With Closed-Loop Power Control,” IEEE Trans. Power Electron., Vol. 29, No. 2, pp. 642–653, 2014.

[27] M. Mehrasa, E. Pouresmaeil, M. Funsho, and B. Nørregaard, “Multilevel converter control approach of active power fi lter for harmonics elimination in electric grids,” Energy, Vol. 84, pp. 722–731, 2015.

[28] G. Mehta and S.P. Singh, “Power Quality Improvement Through Grid Integration of Renewable Energy Sources Power Quality Improvement Through Grid Integration of Renewable Energy Sources,” IETE Journal of Research, Vol. 59, No. 3, pp. 210–218, 2013.

[29] M. G. Villalva, J. R. Gazoli, and E. R. Filho, “Comprehensive Approach to Modeling and Simulation of Photovoltaic Arrays,” IEEE Trans. Power Electron., Vol. 24, No. 5, pp. 1198–1208, 2009.

[30] F.F. Rakotomananandro, “Study of Photovoltaic System,” Master dissertation, The Ohio State University, Ohio, 2011.

[31] Ö. C. Özerdem, S. K. Khadem, S. Biricik, M. Basu, and S. Redif, “Real-time control of shunt active power filter under distorted grid voltage and unbalanced load condition using self-tuning filter,” IET Power Electron., Vol. 7, No. 7, pp. 1895–1905, 2014.

Published

2018-11-27

How to Cite

*Majlesi Journal of Electrical Engineering*,

*13*(1), 109-119. Retrieved from http://mjee.org/index/index.php/ee/article/view/2872

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Articles