Propagation of Overvoltages in the Form of Impulse, Chopped and Oscillating Waveforms in Transformer Windings—Time and Frequency Domain Approach

Marek Florkowski, Jakub Furgał and Maciej Kuniewski
Additional contact information
Marek Florkowski: Department of Electrical and Power Engineering, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
Jakub Furgał: Department of Electrical and Power Engineering, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland
Maciej Kuniewski: Department of Electrical and Power Engineering, AGH University of Science and Technology, al. Mickiewicza 30, 30-059 Kraków, Poland

Energies, 2020, vol. 13, issue 2, 1-16

Abstract: This paper describes a comparison of overvoltage propagation in transformer windings. Expanding and evolving electrical networks comprise various classes of transient waveforms, related to network reconfigurations, failure stages and switching phenomena, including new sources based on power electronics devices. In particular, the integration of renewable energy sources—mainly solar and wind—as well as expanding charging and energy storage infrastructure for electric cars in smart cities results in network flexibility manifested by switching phenomena and transients propagation, both impulse and oscillating. Those external transients, having a magnitude below the applied protection level may have still a considerable effect on winding electrical insulation in transformers, mainly due to internal resonance phenomena, which have been the root cause of many transformer failures. Such cases might occur if the frequency content of the incoming waveform matches the resonance zones of the winding frequency characteristic. Due to this coincidence, the measurements were performed both in time and frequency domain, applying various classes of transients, representing impulse, chopped (time to chopping from 1 µs to 50 µs) and oscillating overvoltages. An additional novelty was a superposition of a full lighting impulse with an oscillating component in the form of a modulated wavelet. The comparison of propagation of those waveforms along the winding length as well as a transfer case between high and low voltage windings were analyzed. The presented mapping of overvoltage prone zones along the winding length can contribute to transformer design optimization, development of novel diagnostic methodology, improved protection concepts and the proper design of modern networks.

Keywords: transformer windings; lightning; chopped; oscillating impulse; overvoltages; modulated wavelet; non-standard voltage waveforms (search for similar items in EconPapers)
JEL-codes: Q Q0 Q4 Q40 Q41 Q42 Q43 Q47 Q48 Q49 (search for similar items in EconPapers)
Date: 2020
References: View references in EconPapers View complete reference list from CitEc
Citations: View citations in EconPapers (6)

Downloads: (external link)
https://www.mdpi.com/1996-1073/13/2/304/pdf (application/pdf)
https://www.mdpi.com/1996-1073/13/2/304/ (text/html)

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:gam:jeners:v:13:y:2020:i:2:p:304-:d:306263

Access Statistics for this article

Energies is currently edited by Ms. Agatha Cao

More articles in Energies from MDPI
Bibliographic data for series maintained by MDPI Indexing Manager ().