Acoustic and HF Detection of Defects on Porcelain Pin Insulators

Abstract

A review of the condition assessment methods of porcelain insulators shows that there is motivation for further improvements particularly regarding applications in distribution systems. Acoustic and high frequency (HF) methods are quite attractive mainly due to better immunity to noise and the relative easiness with which they can be adapted to in-service monitoring applications. These methods have therefore attracted considerable attention in recent research work. A laboratory experiment was set up to study electrical discharges on artificial defects made on porcelain insulators. A standard partial discharge detection method was used simultaneously with acoustic and high frequency techniques. Comparisons and contrasts of the signals were done. All the techniques gave discharge signals that had distinct features for each defect. This opens up opportunities for defect recognition through discharge signal processing.

Third-Rail Insulator Failure Causes and Mitigating Practices: A Comparative Study of Multiple Case Studies in the U.S.

“…Electrical erosion is also a cause of insulators failing [1,21]. Typically, this issue is a result of arcing that occurs between the third rail surface and the current collectors [7,22,23], as the insulator erodes when arcing occurs continuously at a specific location on a third rail [10]. Insulator corrosion is expected to occur inside tunnels, in locations where humidity/water exist [19].…”

“…Some of these practices include internal inspections, rail-walking inspections, regular maintenance, cleaning, etc. [16,22,31]. Cleaning is one of the most common mitigating practices because it prevents the accumulation of dirt on the insulator's surface [32][33][34].…”

Research of Acoustic Measurements of Bending Force on High Voltage Insulators

“…Mechanical loads acting on high voltage insulators have a direct influence on their reliability and durability. Overstressing of these insulators can cause cracking and failure of insulators [3,4]. Information about mechanical stresses of the insulator can be beneficial in increasing safety and reliability.…”

Identification and Extraction of Surface Discharge Acoustic Emission Signals Using Wavelet Neural Network

“…Several researchers successfully used a method of acoustic detection for studying the characteristics of electrical discharges on insulators [3][4]. Many techniques on signal analysis have been used such as Fourier transform, wavelet transform (WT) as well as neural network in order to characterize and classify the electrical discharge signals [5][6]. In some applications, electrical surface discharge detection methods are not very effective, typically as a result of excessive interfering signal [7].…”