Voltage source control of offshore all-DC wind farm

Voltage source control of offshore all-DC wind farm

For access to this article, please select a purchase option:

Buy article PDF
(plus tax if applicable)
Buy Knowledge Pack
10 articles for $120.00
(plus taxes if applicable)

IET members benefit from discounts to all IET publications and free access to E&T Magazine. If you are an IET member, log in to your account and the discounts will automatically be applied.

Learn more about IET membership 

Recommend Title Publication to library

You must fill out fields marked with: *

Librarian details
Your details
Why are you recommending this title?
Select reason:
IET Renewable Power Generation — Recommend this title to your library

Thank you

Your recommendation has been sent to your librarian.

The offshore all-DC wind farm with increasing capacity will bring problems such as the weakening of grid frequency stability and the increase of equivalent grid impedance. To overcome this, a coordinated control strategy for the offshore all-DC wind farm is proposed here with two salient features: better performance under weak grid condition and real-time frequency support from the wind farm. The control strategy consists of three parts: the inertia synchronising control of the receiving-end converter, the constant ratio control of the DC transformer and the frequency response of the wind farm. With the proposed strategy, the all-DC wind farm operates like a synchronous generator to the onshore grid, which provides fast frequency support when the onshore grid frequency changes. The effectiveness of the proposed method is validated in power systems computer aided design (PSCAD)/electromagnetic transients including DC (EMTDC) using a typical IEEE 9 bus system.


    1. 1)
      • 1. Chaudhary, S.K., Teodorescu, R., Rodriguez, P.: ‘Wind farm grid integration using VSC based HVDC transmission—an overview’. Proc. IEEE Energy 2030 Conf., Atlanta, USA, 2008, pp. 17.
    2. 2)
      • 2. Li, G., Li, C., Hertem, D. van.: ‘HVDC technology overview’, in ‘HVDC grids: for offshore and supergrid of the future’ (Wiley, Hoboken, NJ, USA, 2016), ch. 3, pp. 4578.
    3. 3)
      • 3. Shi, G., Cai, X., Sun, C., et al: ‘All-DC offshore wind farm with parallel connection: an overview’. 12th IET Int. Conf. on AC and DC Power Transmission (ACDC 2016), Beijing, 2016, pp. 16.
    4. 4)
      • 4. Holtsmark, N., Bahirat, H.J., Molinas, M., et al: ‘An all-DC offshore wind farm with series-connected turbines: an alternative to the classical parallel AC model?’, IEEE Trans. Ind. Electron., 2013, 60, (6), pp. 24202428.
    5. 5)
      • 5. Zhu, J., Booth, C.D., Adam, G.P., et al: ‘Inertia emulation control strategy for VSC-HVDC transmission systems’, IEEE Trans. Power Syst., 2012, 28, (2), pp. 12771287.
    6. 6)
      • 6. Lee, J., Muljadi, E., Sorensen, P., et al: ‘Releasable kinetic energy-based inertial control of a DFIG wind power plant’, IEEE Trans. Sustain. Energy, 2016, 7, (1), pp. 279288.
    7. 7)
      • 7. Morren, J., De Haan, S.W.H., Kling, W.L., et al: ‘Wind turbines emulating inertia and supporting primary frequency control’, IEEE Trans. Power Syst., 2006, 21, (1), pp. 433434.
    8. 8)
      • 8. Phulpin, Y.: ‘Communication-free inertia and frequency control for wind generators connected by an HVDC-link’, IEEE Trans. Power Syst., 2012, 27, (1), pp. 11361137.
    9. 9)
      • 9. Yang, R., Zhang, C., Cai, X., et al: ‘Autonomous grid-synchronising control of VSC-HVDC with real-time frequency mirroring capability for wind farm integration’, IET Renew. Power Gener., 2018, 12, (13), pp. 15721580.
    10. 10)
      • 10. Yang, R., Zhang, C., Cai, X., et al: ‘Control of VSC-HVDC for wind farm integration with real-time frequency mirroring and self-synchronizing capability’. 2018 Int. Power Electronics Conf. (IPEC-Niigata 2018 -ECCE Asia), Niigata, 2018, pp. 42204226.
    11. 11)
      • 11. Cespedes, M., Sun, J.: ‘Impedance modeling and analysis of grid-connected voltage-source converters’, IEEE Trans. Power Electron., 2014, 29, (3), pp. 12541261.
    12. 12)
      • 12. Zhang, C., Molinas, M., Rygg, A.: ‘Properties and physical interpretation of the dynamic interactions between voltage source converters and grid: electrical oscillation and its stability control’, IET Power Electron., 2017, 10, (8), pp. 894902.
    13. 13)
      • 13. Zhong, Q.C., Weiss, G.: ‘Synchronverters: inverters that mimic synchronous generators’, IEEE Trans. Ind. Electron., 2011, 8, (4), pp. 12591267.
    14. 14)
      • 14. Deng, Y., Harley, R.G.: ‘Space-vector versus nearest-level pulse width modulation for multilevel converters’, IEEE Trans. Power Electron., 2015, 30, (6), pp. 29622974.
    15. 15)
      • 15. Sasongko, F., Hagiwara, M., Akagi, H.: ‘A front-to-front (FTF) system consisting of two modular multilevel cascade converters based on double-star chopper-cells’. 1st Int. Future Energy Electronics Conf. (IFEEC), Tainan, Taiwan, 2013, pp. 488493.
    16. 16)
      • 16. Kenzelmann, S., Rufer, A., Dujic, D., et al: ‘Isolated DC/DC structure based on modular multilevel converter’, IEEE Trans. Power Electron., 2015, 30, (1), pp. 8998.
    17. 17)
      • 17. Gowaid, I.A., Adam, G.P., Massoud, A.M., et al: ‘Quasi two-level operation of modular multilevel converter for use in a high-power DC transformer with DC fault isolation capability’, IEEE Trans. Power Electron., 2015, 30, (1), pp. 108123.
    18. 18)
      • 18. Barrera-Cardenas, R., Molinas, M.: ‘Comparative study of wind turbine power converters based on medium frequency ac-link for offshore DC-grids’, IEEE J. Emerging Sel. Topics Power Electron., 2015, 3, (2), pp. 525541.
    19. 19)
      • 19. Chang, Y., Cai, X., Zhang, J., et al: ‘Bifurcate modular multilevel converter for low-modulation-ratio applications’, IET Power Electron., 2016, 9, (2), pp. 145154.
    20. 20)
      • 20. Ghosh, S., Senroy, N.: ‘Electromechanical dynamics of controlled variable-speed wind turbines’, IEEE Syst. J., 2015, 9, (2), pp. 639646.
    21. 21)
      • 21. Vidyanandan, K.V., Senroy, N.: ‘Primary frequency regulation by deloaded wind turbines using variable droop’, IEEE Trans. Power Syst., 2013, 28, (2), pp. 837846.
    22. 22)
      • 22. EON Netz GmbH: ‘Grid code – high and extra high voltage [DB/EB]’, 2006-06-12. Available at
    23. 23)
      • 23. Hydro-Qébec TransÉnergie: ‘Technical requirements for the connection of generation facilities to the Hydro-Quebec transmission system: supply requirements for wind generation [DB/EB]’, 2003-04-05. Available at
    24. 24)
      • 24. National Grid (Great Britain): ‘Grid code documents: connection conditions [DB/EB]’, 2018-05. Available at

Related content

This is a required field
Please enter a valid email address