Interface temperature evolution exposed to arc discharges occurred on the uniform moist pollution layer of composite insulators based on interface fibre Bragg gratings

Abstract

Arc discharges of moist polluted composite insulators pose a serious threat to the stable operation of transmission line. However, there is no effective detection technology for arc discharges. The evolution mechanism of interface temperature accompanied by arc discharges is not clear. In this paper, a 10 kV composite insulator with quasi‐distributed fibre Bragg gratings (FBGs) embedded at the insulator core‐housing interface was developed. The temperature calibration experiment of interface FBGs, and the arc discharges experiment of the uniform moist polluted composite insulator were conducted. Applied voltage was controlled to get the continuous arc with an arc time of 46 s and the intermittent arc with an arc time of 8 s. Exposed to the two types of surface arcs, the interface temperature evolution was explored. A new phenomenon of the sharp drop of the interface temperature was observed: the interface temperature first drops sharply and then rises rapidly during the continuous arc. Test results show that quasi‐distributed FBGs are valid for detecting the two types of surface arcs by interface temperature rise. This paper provides a technical means to evaluate the state of surface discharges and insulating properties of composite insulators.

Study on the dynamic mechanical properties of winding‐block axial structure considering short circuit strain rate effect

“…The grating area thus achieves the function of a filter. The centre wavelength satisfies the following Bragg characteristics [20]:…”

“…The grating area thus achieves the function of a filter. The centre wavelength satisfies the following Bragg characteristics [20]: $$${\lambda }_{\mathrm{B}}=2{n}_{\text{eff}}\Lambda $$$ where n eff is the effective refractive index of the fibre grating and Λ is the grating period, that is, the distance between two adjacent refractive‐index‐change points.…”

Fibre Bragg Grating Sensors for Condition Monitoring of High-Voltage Assets: A Review

“…This is critical in polluted environments where insulators are susceptible to the high leakage current and discharge activities over their surfaces [144]. Results from dry band arc studies [145][146][147] on insulators with FBG temperature sensors showed a drop in the temperature of the moist polluted composite insulator due to evaporation, followed by rapid increase in temperature during the arc. The arc discharge can therefore be found earlier by using the time point when the temperature begins to drop sharply.…”

Influence of Surface Discharge on Resin Degradation in Decay-like Fracture of Composite Insulators

“…Insulators, which are an essential part of transmission towers, play a vital role, considering that they simultaneously assure both electrical and mechanical reliability [ 3 , 4 ]. In recent years, composite insulators (or polymeric insulators) have become more and more popular in comparison with traditional porcelain and glass insulators due to their excellent hydrophobicity, low weight, and convenience of maintenance [ 5 , 6 ]. For instance, over 10 million strings of composite insulators have already been used at the different levels of high-voltage transmission lines in China [ 7 ].…”