Summary

Temporary overvoltages (TOV) are capable of imposing severe dielectric and thermal stresses on equipment. Although a well-known phenomenon, it is considered only for power frequency, typically. Recent years have shown that low order harmonics during a TOV event should be considered in some scenarios.

Apart from the metal-oxide surge arresters, there are no standardized testing procedures related to the TOV capability of the equipment. Consequently, the TOV withstand characteristics of the equipment is unclear, especially under voltage stresses with harmonic content.

The tutorial will:

  • Introduce the phenomenon and the possible consequences for key apparatus;
  • Discuss grid modelling aspects so that the phenomenon can be properly simulated and captured;
  • Introduce different assessment methods for accounting for the impact of low order harmonics;
  • Introduce and discuss different mitigation strategies;
  • Present practical examples of TOV events involving low order harmonics, compare the different assessment methods, and illustrate the effectiveness of different mitigation options

This webinar is presented by Filipe Faria da Silva, convener of CIGRE Working Group C4.46, "Evaluation of Temporary Overvoltages in Power Systems due to Low Order Harmonic Resonances", that published a Technical Brochure  available on eCIGRE (REF. 913).

Additional informations

Publication type Webinars
Reference WBN047
Publication year
Publisher CIGRE
Study committees
  • Power system technical performance (C4)
Working groups WG C4.46
File size 6 MB
Pages number 87
Price for non member 50 €
Price for member Free

Video

Keywords

Temporary Overvoltage, TOV, Harmonics, Resonances, Insulation Coordination, Surge Arrester, Cables

Evaluation of Temporary Overvoltages in Power Systems due to Low Order Harmonic Resonances
Evaluation of Temporary Overvoltages in Power Systems due to Low Order Harmonic Resonances