In accordance with the unclear scattering gas production characteristics and unknown mechanisms of natural ester insulating oil
this paper establishes an electro-thermal combined stress and cyclic flow experimental platform to investigate the effects of electric field strength
temperature
and flow characteristics on the stray gas production of natural ester insulation oil; the molecular dynamics simulations based on ReaxFF are conducted to elucidate the process and mechanism of gas evolution under electro-thermal combined stress in natural ester insulating oils at both macroscopic and microscopic levels. Experimental and simulation results indicate that
with increasing electric field strength
the content of characteristic gases increases exponentially
and the contents of H2
CO
and CO2 in high electric field samples exceed those in 0 kV/mm samples by 3 to 5 orders of magnitude. The production of characteristic gases increases with the increase of temperature. Increasing the circulation flow of oil samples significantly reduces the production of characteristic gases. In the electrothermal decomposition process
higher electric field strength and longer duration intensify the decomposition of ester molecules
with H2 and CO2 being the main gas products throughout the electro-thermal decomposition process. There are minor differences in gas production pathways among different triglycerides. The achievements of this study provide theoretical guidance and technical references for achieving comprehensive diagnosis of dissolved gases in vegetable insulating oil
effectively assessing the operational status of transformers.