Practical experience of insulation condition evaluation in an on-site HV installation applying a PD measuring procedure

Abstract

Analysis of the types of defects and the degradation modes in different insulation materials of highvoltage (HV) electrical systems has shown that the presence of partial discharges (PD) is a very common characteristic in all of them. Once PD activity is detected, the identification and localization of the associated type of defect is very important to evaluate whether the discharges are harmful or not. During the last two decades, different approaches have been developed and applied to PD measurement and processing techniques to deal with the most common problems arising in on-site and on-line measurements, such as: high levels of background noise, appearance of interferences, simultaneous presence of different PD sources and the difficulty of locating the site of the defects and to identify them. This paper proposes a measuring method together with the implementation of three signal processing tools in order to overcome all these difficulties that appear in on-site and on-line tests. The measuring method has been implemented to evaluate in an on-site practical experience the insulation condition of the power equipment in a GIS substation. After the application of the method, important insulation defects were detected, identified and localized, on time to avoid uncontrolled failures in the electrical system of the substation under test.

Partial Discharge Monitoring on Metal-Enclosed Switchgear with Distributed Non-Contact Sensors

“…These insulation defects can excite partial discharge (PD) under electric fields that are hazardous to insulation but can also be detected for insulation diagnosis. To realize online detection, methods such as ultra-high-frequency (UHF) method [ 5 , 6 , 7 , 8 ], acoustical emission (AE) method [ 9 , 10 , 11 ], and transient earth voltage (TEV) method [ 12 , 13 , 14 ] have been proposed to couple PD signals based on the phenomena of electromagnetic (EM) radiation, acoustic radiation, and transient current flow that accompany PDs, respectively [ 15 ]. Among these methods for online detection of discharge-type insulation failure, the TEV method is the most acceptable for PD detection of metal-enclosed switchgear because of its high sensitivity, broad frequency band, easy installation, and non-electrical contact detection [ 16 , 17 , 18 ].…”

Deep Learning in High Voltage Engineering: A Literature Review

“…As a result, utilities are increasingly favoring defective insulator detection systems that are fast, reliable, and cost-effective. To achieve this objective, it is crucial to select the proper sensors and measurement techniques, as well as to use effective machine/deep learning tools [109,110].…”

Electrical Properties of Different Polymeric Materials and their Applications: The Influence of Electric Field

“…A number of research investigations have analysed PD activity within voids in polymeric insulation systems [5,63,64], but few have analysed voids in polyethylene-terephthalate (PET) insulations [4,65]. PET is a thermoplastic polymer resin belonging to the polyester family.…”