Energy Distribution of Optical Radiation Emitted by Electrical Discharges in Insulating Liquids

Abstract

This article presents the results of the analysis of energy distribution of optical radiation emitted by electrical discharges in insulating liquids, such as synthetic ester, natural ester, and mineral oil. The measurements of optical radiation were carried out on a system of needle–needle type electrodes and on a system for surface discharges, which were immersed in brand new insulating liquids. Optical radiation was recorded using optical spectrophotometry method. On the basis of the obtained results, potential possibilities of using the analysis of the energy distribution of optical radiation as an additional descriptor for the recognition of individual sources of electric discharges were indicated. The results can also be used in the design of various types of detectors, as well as high-voltage diagnostic systems and arc protection systems.

Using the Method of Harmonic Distortion Analysis in Partial Discharge Assessment in Mineral Oil in a Non-Uniform Electric Field

“…The discharges seen in the oils cause the oil to locally warm up and eventually the oil to expand. This phenomenon is visible as the oil movement [11,20,24,34]. Such behavior of the oil was also observed during the studies performed herein, with a significant fluctuation in the oil during intensive discharges.…”

“…Considering mineral oil-based insulation, the processes connected with PDs give reflection in the generation of specific types of gases as a result of the chemical degradation of oil or oil-paper combined insulation due to electrical or thermal stresses. In a more macroscopic scale, the partial discharges have also a significant influence on the energy and power losses resulting from ionization processes associated with PDs or disturbances in the supplying voltage and current (the possible occurrence of harmonic distortion) [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33].…”

“…Some works report also the use of light emitted by partial discharges for the assessment of discharge intensity. A qualitative assessment may be conducted on the basis discharge images, as in [23], or the spectra of emitted light may be compared to conclude on the discharge behavior [24].…”

Comparative Analysis of Optical Radiation Emitted by Electric Arc Generated at AC and DC Voltage

“…In the paper [1], the authors presented a method of CD detection with a cheap CMOS (Complementary Metal-Oxide-Semiconductor) camera recording the spectrum of electromagnetic radiation in the UV (Ultraviolet) and VIS (Visual light) ranges. For measurements of this range of radiation, devices such as spectrophotometers with a larger range of radiation recording can also be used: not only the wider UV range, but also the near infrared (NIR) light frequencies [2]. This is a well-known method for the detection and measurement of partial discharges in power devices [3].…”

High Voltage Insulating Materials—Current State and Prospects

“…Different liquid dielectrics (synthetic ester, natural ester, and mineral oil) were considered in [7] in terms of energy distribution of optical radiation emitted by the surface discharges. The liquid's influence on the emitted radiation range, such as the clear recognition, may be observed between the discharges developed in a given liquid.…”