Long-term aging characteristics of co-filled nano-silica and micro-ATH in HTV silicone rubber composite insulators

Abstract

Multiple environmental stresses produce complex phenomena of aging in polymeric insulators. The main aim of this research is to investigate the improved aging characteristics of silica (SiO2)/alumina trihydrate (ATH) hybrid samples (HSs) in high-temperature vulcanized rubber. For this purpose, three HSs comprising 20% micro-ATH with 2% nano-SiO2 (S2), 4% nano-SiO2 (S4), 6% nano-SiO2 (S6) along with sample-virgin (SV) are subjected to long-term accelerated aging of 9000 h. A special aging chamber is fabricated for the aging process of samples. The aging characteristics of these samples are investigated by measuring leakage current (LC) and hydrophobicity classification (HC) after every weathering cycle. Similarly, Fourier transform infrared (FTIR) spectroscopy is performed to observe the important structural changes over the entire aging time. The dielectric strength of AC is also performed after every 1000 h of aging. Tracking and erosion resistance and mechanical properties are also investigated before and after aging. From the critical investigation, it is observed that HSs possess improved results in all the conducted tests. S2 has the lowest LC and HC values throughout the aging time. Similarly, S6 described the highest breakdown strength at the end of the accelerated aging. In the case of FTIR, it is analyzed that the important wave numbers remain intact for all the HSs in the accelerated aging environment. The loss percentage in the wave number for SV is higher, compared to the HSs. After performing the tracking and erosion resistance test, HSs have superior performance. For some of the mechanical properties, HSs showed improved values. Thus, from the experimental analysis, it is deducted that the sample S2 offers the highest resistance to the aging conditions, compared to the SV and other HSs.

Mechanical Properties of High Temperature Vulcanized Silicone Rubber Aged in the Natural Environment

“…Khan et al studied the effects of inorganic filler ATH on the mechanical properties of sheds. The experiments showed that the particle size and added amount of ATH had little effect on the electrical properties of the sheds, but the mechanical properties were affected [ 14 , 15 , 16 ]. Wang et al [ 17 ] studied the properties of silicone rubber and fluorosilicone rubber under freezing conditions.…”

Study on material and mechanical characteristics of silicone rubber shed of field-aged 110 kV composite insulators

“…The aging characteristics of composite insulator shed are closely related to its operation performance, which has attracted the attention of many experts and scholars. Many studies employ static contact angle test method to analyze the aging characteristics of SIR samples [8][9][10][11] . The relationship between hardening, cracking and aging degree of composite insulator sheds has also been studied [12][13][14] .…”

Review of the Performance of High-Voltage Composite Insulators

“…It appears that a further decrease in the size of the filler may increase the dielectric performance, since this offers even better penetration charge carriers through the bulk of the composite. The authors in [ 62 , 63 ] reported the results of dielectric strength of 9000 h-aged samples in a multi-stress environment of unfilled HTV-SiR and its composites filled with different fillers. Among these, HTV-SiR filled with 6 wt% nano SiO 2 + 20 wt% micro ATH gave the highest AC dielectric strength.…”