Experimental Analysis and Physical Mechanism Investigation of Al۲O۳ Effect on New and Aged Transformer Oil Properties

Al۲O۳ nanoparticles were used to improve the performance of the vital properties of transformer oil (TO) under normal operating conditions and when subjected to thermal aging. Different weight percentages of Al۲O۳ in the TO were considered to maximize the breakdown voltage (BDV). Al۲O۳ nanofluid (NF) increases the BDV by ۱۱۶% (۳۱.۱ kV to ۶۷.۴ kV) and the heat transfer by ۳۳.۴%, and also minimizes partial discharge (PD) by ۶۶%. The reduction of PD is also related to the ability of Al۲O۳ to adsorb hydrogen and acetylene, two oil-soluble gases that are effective in PD. Even Al۲O۳NF was more resistant to water content in TO. BDV for TO and Al۲O۳NF, when water content increased to more than ۳۰ ppm, were reduced by ۵۷% and ۱۹%, respectively. According to Arrhenius equation, both samples were placed at ۱۲۰°C for ۲۹ days to age samples (equivalent to about ۳۰ years). Aged Al۲O۳NF has continued its exceptional performance and improved BDV by ۱۲۱% compared to aged TO, and also Al۲O۳NF showed its capacity well and improved PD compared to aged TO by ۷۱%. All the favorable properties of Al۲O۳NF are conditional on the stability of Al۲O۳. FESEM confirms the stability of Al۲O۳.

کلیدواژه ها:

Transformer oil ، Breakdown Voltage ، Partial discharge ، Thermal Aging ، Physical Mechanism