Dissolved gas analysis and dissipation factor measurement of mineral oil‐based nanofluids under thermal and electrical faults

Abstract

Mineral oil is the most frequent insulating liquid used in oil‐immersed transformers for electrical insulation and heat dissipation. However, oil‐based nanofluids are becoming more popular in scientific research as they have proved to have better dielectric and thermal characteristics. When applying these nanofluids into actual transformers, they would be exposed to thermal and electrical stresses. Thus, The aim of the authors is to investigate the generation pattern of dissolved gases in nanofluids under thermal and electrical faults and to assess the applicability of traditional Dissolved Gas Analysis (DGA) techniques if oil‐based nanofluids are used in transformers. Oil‐based nanofluid samples were prepared using a magnetic stirrer and an ultrasonic homogeniser and then subjected to simulated thermal and electrical faults in the laboratory using properly sealed test cells. Three types of metal oxides, Silicon dioxide, Titanium dioxide, and Aluminium oxide nanoparticles, have been used to prepare nanofluids with 0.02 g/L and 0.04 g/L concentrations. The gases released and dissolved into oil due to the simulated faults were analysed and compared to traditional mineral oil as a benchmark. The dielectric dissipation factor was obtained and analysed for all samples. According to the findings, the presence and concentration of nanoparticles were shown to influence the amount of gases produced. As a result, this research is crucial in guaranteeing that traditional DGA techniques can be employed in transformers that use oil‐based nanofluids.

A new technique for fault diagnosis in transformer insulating oil based on infrared spectroscopy measurements

“…Also, there are two O-Rings for preventing the evolved gases from escaping out of the vessel and the external gases from entering. Note that the clearance and creepage distances were taken into consideration during the design phase for minimising the risk of flashover [16,28].…”

“…The underlying reason behind that returns to the pool boiling phenomenon that limits the temperature of the immersed heating element as reported in Refs. [28,30,31].…”

“…Also, there are two O-Rings for preventing the evolved gases from escaping out of the vessel and the outside gases from entering. The O-Rings are placed as follows: one of them is attached to the downside of the top cap to block the gap between the cap and the vessel, whereas the other one is attached to the downside of the vessel to block the gap between the vessel and the Nylon foundation [28,32].…”

Condition Assessment of Natural Ester–Mineral Oil Mixture Due to Transformer Retrofilling via Sensing Dielectric Properties

“…This parameter is the dissipation factor of the insulating liquid (tan δ ). A high value of the dissipation factor refers to the presence of more existing contaminations and imperfections in the insulating oil [ 31 , 32 ]. Therefore, mitigation of the dissipation factor value provides a positive impact on the insulation system.…”

Influence of Mineral Oil-Based Nanofluids on the Temperature Distribution and Generated Heat Energy Inside Minimum Oil Circuit Breaker in Making Process

“…The results showed that the addition of nanoparticles to mineral oil decreased the DDF after the presence of thermal and electrical faults. Thus, the presence of nanoparticles (such as SiO 2 , Al 2 O 3 , and TiO 2 ) inside the mineral oil increases its lifetime with better performance [ 27 ]. Abdali et al showed that the insertion of 0.01% weight percentage of diamond nanoparticles inside mineral oil can reduce the hotspot temperature to 5.1 °C and enhance the coolant properties of the mineral oil [ 28 ].…”