Differential Analysis of Gas Generation between Gas to Liquid and Mineral Oil under Electric-Thermal Combined Fault

Abstract

Gas to Liquid (GTL), produced from natural gas, possesses excellent environmental and electrical properties, making it suitable as a new type of transformer insulation oil. In order to better understand the gas generation behavior of GTL and analyze its differences from traditional mineral oil, this paper constructs micro-systems for GTL insulation oil and mineral insulation oil based on molecular dynamics simulation, simulating their decomposition processes under electric-thermal combined faults and analyzing the trends in the types and quantities of decomposition products. The simulation results show that the gas generation characteristics of the two types of insulation oil under electric-thermal combined faults are almost similar, but the relative percentage of characteristic gases differs to some extent. The final decomposition products of GTL and mineral oil include small molecular gases and radicals such as C2H4, C2H2, CH4, H2, and C2H6. With the increase in fault temperature, the decomposition of GTL and mineral oil becomes more thorough, and the presence of a strong electric field also accelerates the decomposition. Under the same fault conditions, the proportion of H2 and CH4 generated from the decomposition of GTL is higher by about 5% compared to mineral oil. This study provides theoretical support and references for the fault diagnosis and condition assessment of GTL immersed transformers.