Mechanism of fracture related heating for 500-kV composite insulators in highly humid areas

Abstract

Summary With the adoption of composite insulators in the field of high voltage transmission, it is essential to focus on its safety performance. Our study paid attention to the extensive heating within HV ending of 500‐kV AC composite insulators in southern China with high level of humidity and proposed corresponding countermeasures. Via superficial examination, IR and UV test, interface quality inspection, chemical analysis and water absorption test and etc., we were able to study the defected insulators. According to our observation, insulators were slightly covered with pollutants and maintained superficial hydrophobic properties. The heating performance of HV ending of insulators was closely related to humidity as well as the type and site of loading voltage. We suggested that when exposed to high humidity, polarization of the molecules from water, polar groups of material and the interlayer resulted in the abnormal heating; on the other hand, when the environment humidity was low the heating was attributed to partial discharge. Consequently, we provided several solutions toward the issue according to our observations. Copyright © 2015 John Wiley & Sons, Ltd.

Study on decay‐like fracture of 500 kV composite insulators: Infrared, ultraviolet and electric field distribution detection

“…In accordance with the above characteristics and FTIR (Fourier transform infrared spectroscopy) properties, the 'gully and fracture' on the core rod surface confirms the presence of acid and heat [9,10,26,27]. The 'crisp' and 'decay' of the core rod are due to the epoxy resin modification by acid and heat, resulting in disappearance of its internal components in the form of gas.…”

“…1 insulator. The temperature rise of the operating composite insulator on the transmission line is measured, and the temperature rise generally does not exceed 30 K [10, 24–26]. Different temperatures and temperature rises indicate different degradation degrees of the core rod.…”

“…Literature [8][9][10][11][12] carried out experiments on the decay-like fractured insulators and obtained the hydrophobicity, morphology, and physicochemical properties. Literature [11,[24][25][26] carried out IR and UV imaging tests on the decay-like fractured insulators in the laboratory. Based on the current status and conclusions, electric field distortion and electrical discharge play an important role in the decay-like formation and abnormal temperature rise during operation.…”

“…1 insulator. The temperature rise of the operating composite insulator on the transmission line is measured, and the temperature rise generally does not exceed 30 K[10,[24][25][26]. Different…”

Laser-induced breakdown spectroscopy of aqueous silicone rubber in an argon environment

“…In 2013, a provincial branch of a power grid company conducted an infrared temperature measurement inspection of 4,692 lines using composite insulators across the grid, with the results revealing that four lines exhibited abnormal heating. In high humidity climates, polarization of the molecules from water, polar groups of material and the interlayer resulted in the abnormal heating (Cheng et al, 2016).…”