Separation of sources in radiofrequency measurements of partial discharges using time-power ratio maps

R Albarracin; G Robles; J M Martinez-Tarifa; J Ardila-Rey

doi:10.1016/j.isatra.2015.04.006

Separation of sources in radiofrequency measurements of partial discharges using time-power ratio maps

ISA Trans. 2015 Sep:58:389-97. doi: 10.1016/j.isatra.2015.04.006. Epub 2015 May 18.

Authors

R Albarracin¹, G Robles², J M Martinez-Tarifa³, J Ardila-Rey⁴

Affiliations

¹ Department of Electrical Engineering, Universidad Carlos III de Madrid, Leganés -28911, Spain. Electronic address: rasbarracin@gmail.com.
² Department of Electrical Engineering, Universidad Carlos III de Madrid, Leganés -28911, Spain. Electronic address: grobles@ing.uc3m.es.
³ Department of Electrical Engineering, Universidad Carlos III de Madrid, Leganés -28911, Spain. Electronic address: jmmtarif@ing.uc3m.es.
⁴ Department of Electrical Engineering, Universidad Técnica Federico Santa María, Santiago de Chile, Chile. Electronic address: jorge.ardila@usm.cl.

PMID: 25997372
DOI: 10.1016/j.isatra.2015.04.006

Abstract

Partial discharges measurement is one of the most useful tools for condition monitoring of high-voltage (HV) equipment. These phenomena can be measured on-line in radiofrequency (RF) with sensors such as the Vivaldi antenna, used in this paper, which improves the signal-to-noise ratio by rejecting FM and low-frequency TV bands. Additionally, the power ratios (PR), a signal-processing technique based on the power distribution of the incoming signals in frequency bands, are used to characterize different sources of PD and electromagnetic noise (EMN). The calculation of the time length of the pulses is introduced to separate signals where the PR alone do not give a conclusive solution. Thus, if several EM sources could be previously calibrated, it is possible to detect pulses corresponding to PD activity.

Keywords: Condition monitoring; Dielectric materials; Partial discharges; RF measurements; Spectral power; VHF and UHF measurements; Vivaldi antennas.