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e & i Elektrotechnik und Informationstechnik

, Volume 135, Issue 8, pp 576–601 | Cite as

The impact of the uncoordinated local control of decentralized generation on the reactive power margin

  • Christian Schirmer
  • Albana Ilo
CIGRE 2018
  • 9 Downloads

Abstract

The penetration of decentralized generation entails considerable challenges to keep the reactive power flow at the required levels and to ensure the voltage stability in high voltage grid (Lund in IEEE power engineering society general meeting, 2007). The use of the uncoordinated local control in distributed generation level (e.g. in medium voltage level) creates an uncontrolled reactive power flow on the higher-level grid (e.g. high voltage grid) (Ilo et al. in CIRED, 23rd international conference on electricity distribution, 2015; Ilo in Sci. Res. 7:217–232, 2016). Additionally, it systematically modifies the lumped load behavior seen from high voltage grid and thus also its voltage stability phenomenon.

The main focus of this Paper is the impact assessment of the boundaries modelling of the high voltage grid in presence of a large decentralized generation share on the reactive power margin. Traditionally the modelling of the high voltage grid boundaries has been done using lumped loads and the corresponding ZIP model which is not accurate enough for this investigation.

We start with the description of the methodology used for the adequate modelling of the high voltage grid boundaries in case of a large penetration of decentralized generation, which is already retrofitted with local control. Different simulation scenarios, e.g. varying the load situation, varying the amount of conventional power production and distributed generation production have been defined. The simulations are being performed on a test grid, which is based on the European Power Grid configuration (CIGRE task force C6.04, 2014). This test grid consists of a meshed 380 kV and 220 kV transmission grid, a slightly meshed 110 kV and a normally radial operated 20 kV grid. One of the 20 kV sub-systems, which includes decentralized generators, is modelled in detail. The other 20 kV sub-grids are modelled through adequate equivalent lumped loads and injections at the power supply substation busses. The low voltage sub-grids, which also include a high share on distributed generators, are modelled through the adequate equivalent lumped loads and injections at the distribution transformer buses. All decentralized generators connected to it are equipped with \(Q(U)\) local control to keep the voltage in the distribution grids within the limits. The modelling of boundaries is extended by the equivalent injection and local control. The static voltage stability is being investigated by creating \(V\)\(Q\) curves and using the \(\mathrm{d}\Delta Q/\mathrm{d}V\) criterion for all selected grid nodes (Clark in Power technologies, 1990). This method provides an indicator of the high voltage grid stability in total as well as the individual reactive power margin for each analyzed grid node. Finally, the node, which is closest to an instable operating point and the corresponding simulation scenario, is being detected.

Keywords

Voltage stability Load behaviour \(V\)\(Q\) curve \(\mathrm{d}\Delta Q/\mathrm{d}V\) criterion Reactive power margin 

Notes

Acknowledgements

This work is done as part of DeCas-Project, which has received funding in the framework of the joint programming initiative ERA-Net Smart Grids Plus, with support from the European Union’s Horizon 2020 research and innovation programme.

References

  1. 1.
    Lund, P. (2007): The Danish cell project, part 1: background and general approach. In IEEE power engineering society general meeting. Google Scholar
  2. 2.
    Ilo, A., Gawlik, W., Schaffer, W., Eichler, R. (2015): Uncontrolled reactive power flow due to local control of distributed generators. In CIRED, 23rd international conference on electricity distributionCIRED, 23rd international conference on electricity distribution (0512). Google Scholar
  3. 3.
    Ilo, A. (2016): Effects of the reactive power injection on the grid—the rise of the volt/var interaction chain. Sci. Res., 7, 217–232.  https://doi.org/10.4236/sgre.2016.77017. CrossRefGoogle Scholar
  4. 4.
    CIGRE task force C6.04 (2014): Benchmark systems for network integration of renewable and distributed energy resources. In: CIGRE. Google Scholar
  5. 5.
    Clark, H. K. (1990): Voltage stability analysis requires accurate \(Q\)\(V\) curves. Power technologies (p. 61). Google Scholar
  6. 6.
    Bertani, A., Borghetti, A., Bossi, C., De Biase, L., Lamquet, O., Massuco, S., Morini, A., Nucci, A. A., Paolone, M., Quaia, E., Silvestro, F. (2006): Management of low voltage grids with high penetration of distributed generation: concepts, implementations and experiments. In CIGRE (C6-304). Google Scholar
  7. 7.
    Taljan, G., Krasnitzer, M., Strempfl, F., Jarz, A. (2012): Spannungsregelung im 30 kV Netz UW Judenburg/West Lö-sungsansätze mit Smart Grids. In 12. Symposium Energieinnovation, Graz, Austria, 15–17 Februar 2012. Google Scholar
  8. 8.
    Schäfer, P., Krahl, S., Vennegeerts, H., Moser, A. (2013): Spannungsebenen Übergreifendes Regelungskonzept für Blindleistung. In ETG Congress, Berlin, Germany, 5–6 November 2013. Google Scholar
  9. 9.
    Technical guideline (2008): Guideline for generating plants’ connection to and parallel operation with the medium-voltage network. BDEW Bundesverband der Energie- und Wasserwirtschaft e.V., June 2008. Available in http://grouper.ieee.org/groups/scc21/1547a/email/pdfkz5Zov6vtg.pdf.
  10. 10.
    IEEE draft recommended practice for establishing methods and procedures that provide supplemental support for implementation strategies for expanded use of IEEE standard 1547 (2014): In IEEE P1547.8/D8, July 2014 (pp. 1–176). Google Scholar
  11. 11.
    Heinhold, L., Stubbe, R. (1989): Kabel und Leitungen für Starkstrom. Berlin: Siemens. Google Scholar
  12. 12.
    Machowski, J., Bialek, J. W., Bumby, J. R. (2008): Power system dynamics: stability and control. New York: Wiley. Google Scholar
  13. 13.
    Lin, K., Holbert, K. E. (2008): Applying the equivalent pi circuit to the modeling of hydraulic pressurized linzes. ScienceDirect, 8 November 2008. Google Scholar
  14. 14.
    Elbs, C., Nenning, R., Pardatscher, R., Witzmann, R. (2014): Einsatz der \(Q(U)\)-Regelung bei der Vorarlberger energienetze GmbH. Endbericht, 30.06.2014. Google Scholar
  15. 15.
    Van Cutsem, T. (1991): A Method to compute reactive power margins with respect to voltage collapse. IEEE Trans. Power Syst., 6(1), 145–156. CrossRefGoogle Scholar

Copyright information

© CIGRE - Reprint from www.cigre.org with kind permission 2018

Authors and Affiliations

  1. 1.Institute of Energy Systems and Electrical DrivesVienna University of TechnologyViennaAustria

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