Skip to main content
SpringerLink
Log in

Verification of withstand capability for very fast transients of a 200 MVA, 500 kV GSU transformer by modelling and testing

  • CIGRE 2020
  • Published:
e & i Elektrotechnik und Informationstechnik Aims and scope Submit manuscript

Abstract

Transformers in the network are often exposed to voltage stresses that are different from the impulses during the factory assessment tests (FAT). In many cases transformers can withstand these voltages. In combination with gas-insulated switch gears (GIS), it is typical that these voltages are characterized by a very high steepness in combination with a short duration time called very fast transients (VFT). Since for VFT voltages the difference to the FAT is remarkable, customers ask for an extended proof of the withstand capability.

It is also clear that customers are conducting their own system studies, on the one hand, to get more detailed knowledge about voltage stresses to be expected at switching events and fault events. On the other hand, it is important to consider these results when doing the specification for transformers to connect to GIS.

To cover these requirements, a step-by-step approach was followed starting with providing simplified transformer models and calculating the frequency response based on the manufacturer’s white-box model. These models are delivered to the customer. Resonance frequencies are derived, and the safety margins as well a proof for acceptable resonant voltages, e.g., the HV terminal, is given.

Next, to prove the withstand capability for voltage stresses at energisation, inductive opening, reignitions and disconnecting events are performed. Due to the content of very high frequencies in the signals – going up to 5 MHz – it is necessary to use proper models during the design process of the transformer. Turn-wise models of the transformer windings provide a sufficient resolution for the required frequency range (>10 MHz). The use of turn-wise models of the transformer’s windings is mandatory.

It is a challenge that a transformer can reliably withstand the VFT voltages. The withstand capability is proven by numerical simulation as well as by a special test. In the test sequence a very steep chopping, by applying a special SF6 chopping device with customer-specified voltage levels, finally successfully proved the transformer’s withstand capability for VFT.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1.
Fig. 2.
Fig. 3.
Fig. 4.
Fig. 5.
Fig. 6.
Fig. 7.
Fig. 8.
Fig. 9.
Fig. 10.
Fig. 11.
Fig. 12.
Fig. 13.

References

  1. CIGRE TB 577A (2014): Electrical transient interaction between transformers and the power system, part 1- expertise, joint working group A2/C4.39.

  2. CIGRE TB 577B (2014): Electrical transient interaction between transformers and the power system, part 2- case studies, joint working group A2/C4.39.

  3. Narimatsu, S., Yamaguchi, K., Nakano, S., Maruyama, S. (1981): Interrupting performance of capacitive current by disconnecting switch for gas insulated switchgear. IEEE Trans. Power Appar. Syst., PAS-100(6), 2726–2732.

    Article  Google Scholar 

  4. Boeck, W., Witzmann, R. (1989): Critical GIS configurations with respect to VFT. In Sixth international symposium on high voltage engineering, New Orleans, LA, USA, August 28–September 1, 1989.

    Google Scholar 

  5. Ikeda, M., Fukumoto, S., Takao, H., Ohtsuka, S., Haginomori, E., Hikita, M. (2002): Breakdown characteristics of oil and paper insulation for a very fast transient voltage. Electr. Eng. Jpn., 141(4), 16–24.

    Article  Google Scholar 

  6. Nakanishi, K., Fujita, S., Kurita, H., Kishi, A., Shibuya, Y. (1997): High frequency voltage oscillation in transformer windings and electrical breakdown properties of interturn insulation immersed in oil at VFT voltage. In IEEE annual report-conference on electrical insulation and dielectric phenomena, Minneapolis, October 19-22, 1997.

    Google Scholar 

  7. Krithika, S., Usa, S. (2013): Volt-time characteristics of OIP under non-standard impulses. In 2013 IEEE 1st international conference on condition assessment techniques in electrical systems, CATCON, Kolkata, 2013. https://doi.org/10.1109/CATCON.2013.6737513.

    Chapter  Google Scholar 

  8. Vandermaar, A. J., Wang, M., Neilson, J. B., Srivastava, K. D. (1994): The electrical breakdown characteristics of oil-paper insulation under steep front impulse voltages. IEEE Trans. Power Deliv., 9(4), 1926–1935. https://doi.org/10.1109/61.329525.

    Article  Google Scholar 

  9. Wang, M. (1991): The electrical breakdown characteristics of oil/paper insulation under fast front voltages. Master-thesis, University of British Columbia.

  10. Bavisha, T., Usa, S. (2017): Impulse breakdown characteristics of aged oil impregnated paper. IEEE Trans. Dielectr. Electr. Insul., 24(4), 2354–2361. https://doi.org/10.1109/TDEI.2017.006456.

    Article  Google Scholar 

  11. Bavisha, T., Aniruthaan, K., Usa, S. (2017): Withstand capability of transformers under very fast transients. In 2017 3rd international conference on condition assessment techniques in electrical systems, CATCON, Rupnagar, 2017 (pp. 320–325). https://doi.org/10.1109/CATCON.2017.8280237

    Chapter  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Transformers Research, Siemens AG Austria, Weiz, Austria

    A. Rabel

  2. Transformers Research, Siemens China, Jinan, China

    J.-J. Zhou

Authors
  1. A. Rabel
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. J.-J. Zhou
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to A. Rabel.

Additional information

Publisher’s Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Paper submitted for the CIGRE Session 2020, SC-A2, August 31–September 1, 2020, online.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Rabel, A., Zhou, JJ. Verification of withstand capability for very fast transients of a 200 MVA, 500 kV GSU transformer by modelling and testing. Elektrotech. Inftech. 137, 437–443 (2020). https://doi.org/10.1007/s00502-020-00849-y

Download citation

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s00502-020-00849-y

Keywords

Search

Navigation