Decentralised control method for DC microgrids with improved current sharing accuracy

Jie Yang; Xinmin Jin; Xuezhi Wu; Pablo Acuna; Ricardo P. Aguilera; Thomas Morstyn; Vassilios G. Agelidis

Decentralised control method for DC microgrids with improved current sharing accuracy

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Author(s): Jie Yang ¹ ; Xinmin Jin ¹ ; Xuezhi Wu ¹ ; Pablo Acuna ² ; Ricardo P. Aguilera ³ ; Thomas Morstyn ² ; Vassilios G. Agelidis ⁴
- Affiliations: 1: National Active Distribution Network Technology Research Center, Beijing Jiaotong University, Beijing, People's Republic of China ;
  2: School of Electrical Engineering and Telecommunications, University of New South Wales, Sydney, Australia ;
  3: School of Electrical, Mechanical and Mechatronic Systems, University of Technology Sydney, Sydney, Australia ;
  4: Electric Power and Energy (CEE), Department of Electrical Engineering, Technical University of Denmark, Kgs. Lyngby, Denmark
Source: Volume 11, Issue 3, 16 February 2017, p. 696 – 706
DOI: 10.1049/iet-gtd.2016.0295 , Print ISSN 1751-8687, Online ISSN 1751-8695

Received 01/03/2016, Accepted 14/07/2016, Revised 15/06/2016, Published 16/02/2017

A decentralised control method that deals with current sharing issues in dc microgrids (MGs) is proposed in this study. The proposed method is formulated in terms of ‘modified global indicator’ concept, which was originally proposed to improve reactive power sharing in ac MGs. In this work, the ‘modified global indicator’ concept is extended to coordinate dc MGs, which aims to preserve the main features offered by decentralised control methods such as no need of communication links, central controller or knowledge of the microgrid topology and parameters. This global indicator is inserted between current and voltage variables by adopting a virtual capacitor, which directly produces an output current sharing performance that is less relied on mismatches of the multi-bus network. Meanwhile, a voltage stabiliser is complementary developed to maintain output voltage magnitude at steady state through a shunt virtual resistance. The operation under multiple dc-buses is also included in order to enhance the applicability of the proposed controller. A detailed mathematical model including the effect of network mismatches is derived for analysis of the stability of the proposed controller. The feasibility and effectiveness of the proposed control strategy are validated by simulation and experimental results.

References

1. 1)
  - 3. Dou, C., Lv, M., Zhao, T., et al: ‘Decentralised coordinated control of microgrid based on multi-agent system’, IET Gener. Transm. Distrib., 2015, 9, (16), pp. 2474–2484 (doi: 10.1049/iet-gtd.2015.0397).
2. 2)
  - 8. Xiao, J., Setyawan, L., Wang, P., et al: ‘Power-capacity-based bus-voltage region partition and online droop coefficient tuning for real-time operation of dc microgrids’, IEEE Trans. Energy Convers., 2015, 12, (30), pp. 1338–1347 (doi: 10.1109/TEC.2015.2451131).
3. 3)
  - 6. Sao, C., Lehn, P.: ‘Control and power management of converter fed microgrids’, IEEE Trans. Power Syst., 2008, 23, (3), pp. 1088–1098 (doi: 10.1109/TPWRS.2008.922232).
4. 4)
  - 50. Nasirian, V., Moayedi, S., Davoudi, A., et al: ‘Distributed cooperative control of dc microgrids’, IEEE Trans. Power Electron., 2015, 30, (4), pp. 2288–2303 (doi: 10.1109/TPEL.2014.2324579).
5. 5)
  - 12. Rokrok, E., Golshan, M.E.H.: ‘Adaptive voltage droop scheme for voltage source converters in an islanded multibus microgrid’, IET Gener. Transm. Distrib., 2010, 4, pp. 562–578 (doi: 10.1049/iet-gtd.2009.0146).
6. 6)
  - 22. Lu, X., Guerrero, J., Sun, K., et al: ‘An improved droop control method for dc microgrids based on low bandwidth communication with dc bus voltage restoration and enhanced current sharing accuracy’, IEEE Trans. Power Electron., 2014, 29, (4), pp. 1800–1812 (doi: 10.1109/TPEL.2013.2266419).
7. 7)
  - 21. Anand, S., Fernandes, B.G., Guerrero, M.: ‘Distributed control to ensure proportional load sharing and improve voltage regulation in low-voltage dc microgrids’, IEEE Trans. Power Electron., 2013, 28, (4), pp. 1900–1913 (doi: 10.1109/TPEL.2012.2215055).
8. 8)
  - 26. Morstyn, T., Hredzak, B., Agelidis, V.: ‘Cooperative multi-agent control of heterogeneous storage devices distributed in a dc microgrid’, IEEE Trans. Power Syst., 2015, Advance online publication, 2015, 31, (4), pp. 2974–2986 (doi: 10.1109/TPWRS.2015.2469725).
9. 9)
  - 30. Gu, Y., Xiang, X., Li, W., et al: ‘Mode-adaptive decentralized control for renewable dc microgrid with enhanced reliability and flexibility’, IEEE Trans. Power Electron., 2014, 9, (29), pp. 5072–5080 (doi: 10.1109/TPEL.2013.2294204).
10. 10)
  - 2. Wang, P., Jin, C., Zhu, D., et al: ‘Distributed control for autonomous operation of a three-port AC/DC/DS hybrid microgrid’, IEEE Trans. Ind. Electron., 2015, 2, (62), pp. 1279–1290 (doi: 10.1109/TIE.2014.2347913).
11. 11)
  - 5. Khorsandi, A., Ashourloo, M., Mokhtari, H., et al: ‘Automatic droop control for a low voltage dc microgrid’, IET Gener. Transm. Distrib., 2016, 10, (1), pp. 41–47 (doi: 10.1049/iet-gtd.2014.1228).
12. 12)
  - 63. Guerrero, J.M., Vasquez, J.C., Matas, J., de Vicuna, L.G., Castilla, M.: ‘Hierarchical control of droop-controlled AC and DC microgrids – a general approach toward standardization’, IEEE Trans. Ind. Electron., 2011, 58, (1), pp. 158–172 (doi: 10.1109/TIE.2010.2066534).
13. 13)
  - 29. Loh, P.C., Li, D., Chai, Y.K., et al: ‘Autonomous operation of hybrid microgrid with AC and DC sub-grids’, IEEE Trans. Ind. Appl., 2013, 49, (3), pp. 1374–1382 (doi: 10.1109/TIA.2013.2252319).
14. 14)
  - 10. Lee, C., Chu, C., Cheng, P.: ‘A new droop control method for the autonomous operation of distributed energy resource interface converters’, IEEE Trans. Power Electron., 2013, 28, (4), pp. 1980–1993 (doi: 10.1109/TPEL.2012.2205944).
15. 15)
  - 14. Sun, X., Hao, Y., Wu, Q., et al: ‘A multifunctional and wireless droop control for distributed energy storage units in Islanded AC microgrid applications’, IEEE Trans. Power Electron., Advance online publication, 2016, PP, (99), pp. 1–16.
16. 16)
  - 6. Kumar, M., Srivastava, S., Singh, S.: ‘Control strategies of a dc microgrid for grid connected and islanded operations’, IEEE Trans. Smart Grid, 2015, 7, (6), pp. 1588–1601 (doi: 10.1109/TSG.2015.2394490).
17. 17)
  - 20. Khorsandi, A., Ashourloo, M., Mokhtari, H.: ‘A decentralized control method for a low-voltage dc microgrid’, IEEE Trans. Energy Convers., 2014, 29, (4), pp. 793–801 (doi: 10.1109/TEC.2014.2329236).
18. 18)
  - 28. Augustine, S., Mishra, M.K., Lakshminarasamma, N.: ‘Adaptive droop strategy for load sharing and circulating current minimization in low-voltage standalone DC microgrid’, IEEE Trans. Sustain. Energy, 2015, 6, (1), pp. 132–141 (doi: 10.1109/TSTE.2014.2360628).
19. 19)
  - 11. Zhong, Q.-C.: ‘Robust droop controller for accurate proportional load sharing among inverters operated in parallel’, IEEE Trans. Ind. Electron., 2013, 60, (4), pp. 1281–1290 (doi: 10.1109/TIE.2011.2146221).
20. 20)
  - 4. Ma, W.-J., Wang, J., Lu, X., et al: ‘Optimal operation mode selection for a dc microgrid’, IEEE Trans. Smart Grid, 2016, Advance online publication, 2016, PP, (99), pp. 1–9.
21. 21)
  - 11. Huang, P.H., Liu, P.C., Xiao, W., et al: ‘A novel droop-based average voltage sharing control strategy for DC microgrids’, IEEE Trans. Smart Grid, 2015, 6, (3), pp. 1096–1106 (doi: 10.1109/TSG.2014.2357179).
22. 22)
  - 29. Wang, P., Lu, X., Yang, X., et al: ‘An improved distributed secondary control method for DC microgrids with enhanced dynamic current sharing performance’, IEEE Trans. Power Electron., 2016, 9, (31), pp. 6658–6673 (doi: 10.1109/TPEL.2015.2499310).
23. 23)
  - 20. Han, H., Liu, Y., Sun, Y., et al: ‘An improved droop control strategy for reactive power sharing in islanded microgrid’, IEEE Trans. Power Electron., 2015, 6, (30), pp. 3133–3141 (doi: 10.1109/TPEL.2014.2332181).
24. 24)
  - 18. Barklund, E., Pogaku, N., Prodanovic, M., et al: ‘Energy management in autonomous microgrid using stability-constrained droop control of inverters’, IEEE Trans. Power Electron., 2008, 23, (5), pp. 2346–2352 (doi: 10.1109/TPEL.2008.2001910).
25. 25)
  - 10. Bidram, A., Davoudi, A., Lewis, F.L., Zhihua, Q.: ‘Secondary control of microgrids based on distributed cooperative control of multi-agent systems’, IET Gener. Transm. Distrib., 2013, 7, (8), pp. 822–831 (doi: 10.1049/iet-gtd.2012.0576).
26. 26)
  - 16. Tuladhar, A., Jin, K.: ‘A novel control technique to operate dc/dc converters in parallel with no control interconnections’. 29th Annual IEEE Power Electronics Specialists Conf., 1998. PESC 98 Record.Fukuoka, Japan, May 1998, pp. 892–898.
27. 27)
  - 10. Sao, C., Lehn, P.: ‘Autonomous load sharing of voltage source converters’, IEEE Trans. Power Deliv., 2005, 20, (2), pp. 1009–1016 (doi: 10.1109/TPWRD.2004.838638).
28. 28)
  - 27. Cai, W., Liu, B., Duan, S., et al: ‘An active low-frequency ripple control method based on the virtual capacitor concept for BIPV systems’, IEEE Trans. Power Electron., 2014, 4, (29), pp. 1733–1745 (doi: 10.1109/TPEL.2013.2271247).
29. 29)
  - 15. Li, C., Chaudhary, S.K., Savaghebi, M., et al: ‘Power flow analysis for low-voltage AC and DC microgrids considering droop control and virtual impedance’, IEEE Trans. Smart Grid, Advance online publication, 2016, PP, (99), pp. 1–11.
30. 30)
  - 1. Lasseter, R.: ‘Microgrids’. IEEE Power Engineering Society Winter Meeting, 2002, New York, US, January 2002, pp. 305–308.

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