Dissolved gas analysis (DGA) is currently one of the most effective and widely applied methods for transformer fault diagnosis and early warning. Investigating the gas generation characteristics of transformer oil at different fault temperatures is of great significance for improving the accuracy of transformer oil overheating fault diagnosis and promoting the application of new environmentally friendly transformer oils. Based on the introduction of the fault causes and the gas generation mechanism of transformer oil under localized overheating

this paper classifies the existing overheating gas generation experimental platforms external heating

immersion

and tube heating experimental platforms

and summarizes their advantages and disadvantages. Special focus is placed on the key issues encountered in simulating medium- and high-temperature overheating by using immersion overheating platforms. The paper highlights the current lack of effective methods to verify the accuracy of simulated transformer overheating faults and suggests the challenges and directions for immersion overheating platforms. After introducing the characteristics of molecular dynamics

the paper summarizes research achievements and limitations in the decomposition mechanisms of mineral oil

natural esters

and synthetic esters based on molecular dynamics. It also reviews studies on the influence of electric fields and other substances in oil on the thermal decomposition process and gas generation characteristics of transformer oil

offering a perspective on future research directions.