近年来，变压器套管爆燃事故屡次发生，造成了严重的变电站主变停运事故，对电网输变电端安全运行造成了影响。针对高压变压器油纸电容式套管的爆燃问题，本文以爆燃过程模型为基础，结合电弧爆燃试验和多物理场有限元仿真，对套管在电弧作用下的爆燃机理和电弧作用特性进行了研究。首先对套管的电热特性及电弧爆燃条件进行了研究。使用 comsol 多物理场仿真平台建立了简化的套管电容芯子模型，并对套管的电热场进行计算，套管的电场分布决定了电容芯子沿面部位容易放电，热场分布决定其不可长期运行于过载状态。对四起典型套管爆燃事故进行调研比对，总结其放电路径、故障波形、故障痕迹，进而总结出“爆燃模型”，即套管爆燃的过程总是先发生外壳破损的物理爆炸，然后发生可燃油气的化学爆炸及燃烧，且燃烧过程的发生具有不确定性。在开放环境下进行电弧下绝缘油可爆性验证和垂直燃烧法下油纸可燃性验证，证明外壳破损后，油和纸由绝缘材料转为可爆可燃材料。其次，对不同能量等级电弧作用下油纸绝缘的作用特性进行了研究。在密闭充油容器中进行小电弧放电实验，研究放电过程中的温度和压力变化，容器内的压力变化为先上升后逐渐下降至常压，说明产生的气体经扩散溶解后，对容器内的压强影响不大，随着容器内油温降为常温，压力也随着降低。在脆性圆柱石英玻璃容器中，进行中等电弧放电实验，它的爆燃过程符合“先爆后燃”的特征。验证了“爆燃模型”的正确性。最后在退役套管中设置大能量电弧，模拟和复现事故中的爆燃现象，其压力变化可达 5MPa。在前期研究基础上，对套管爆燃的临界参数进行研究。将“爆”设定为爆燃的关键阈值，在此基础上对套管瓷套的易爆性进行研究。电弧非直接接触瓷套时，基于相场法及计算流体力学理论，对上下瓷套的耐压临界值和电弧能量与套管内部压强的对应关系进行了计算。当套管底部的电弧能量达到 3.5×10^5J 时，套管内油隙的相变过压最大值达到下瓷套的临界耐压值，引起下瓷套的炸裂。电弧直接接触瓷套时，基于固体力学的有限元仿真，对瓷套所受的热应力进行仿真。发现电弧直接接触时，即便是温度较低的外围区域，也足以使瓷套热应力大于抗拉强度而碎裂。

In recent years, the transformer bushing explosion accidents have occurred repeatedly, resulting in a lot of substation main transformer shutdown accidents, which affects the safety of the grid transmission.Focused on the high-voltage oil impregnated paper bushing explosion characteristics, based on the explosion model, combined with the arc explosion test and multi-physical field finite element simulation, this paper aims to study the bushing explosion mechanism and arc action characteristic.The initial phase of this study involved an examination of the electrical and thermal properties of bushings, as well as the conditions that lead to arc ignition and subsequent explosion. A simplified model of a bushing's capacitor core was constructed using the COMSOL Multiphysics simulation platform to facilitate the computation of the electrical and thermal fields within the bushing. It was determined that the distribution of the electric field within the bushing predisposes the surface areas of the capacitor core to discharge phenomena, while the thermal field distribution indicates that the bushing cannot sustain long-term operation in an overloaded state. An analysis and comparison of four typical bushing explosion incidents were conducted to identify commonalities in discharge paths, fault waveforms, and failure marks, leading to the formulation of an "explosion model." This model posits that the process of a bushing explosion invariably begins with a physical explosion due to shell rupture, followed by a chemical explosion and combustion of combustible oil and gas, with the occurrence of the combustion process being subject to uncertainty. Experiments were conducted in an open environment to validate the explosiveness of insulating oil under arc conditions and the combustibility of oil-impregnated paper using a vertical burning method, confirming that upon shell rupture, the oil and paper transition from insulating materials to explosive and combustible materials.Subsequently, the study focused on the characteristics of oil-paper insulation under the influence of electric arcs of varying energy levels. Experiments involving minor arc discharges were conducted within sealed, oil-filled containers to investigate the changes in temperature and pressure during the discharge process. The observed pattern of pressure changes within the container initially showed an increase, followed by a gradual decline back to atmospheric pressure. This indicated that the gases produced were effectively diffused and dissolved, minimizing their impact on the internal pressure. As the temperature of the oil within the container returned to ambient levels, the pressure correspondingly decreased. Medium-level arc discharge experiments were carried out in brittle cylindrical quartz glass containers, validating the accuracy of the "explosion model." Finally, high-energy arc discharges were initiated within decommissioned bushings to simulate and replicate the explosive phenomena observed in actual incidents, with recorded pressure changes reaching up to 5MPa.Based on the preliminary research, the study delved into the critical parameters for bushing explosion phenomena. The threshold for explosion, designated as the key value for explosive events, served as the foundation for examining the susceptibility of the ceramic bushing to explosive rupture. When the electric arc does not directly contact the ceramic bushing, the phase-field method combined with computational fluid dynamics (CFD) theory was employed to calculate the critical pressure resistance values of the upper and lower ceramic bushings and to establish the relationship between arc energy and the internal pressure of the bushing. It was found that when the energy of the arc at the base of the bushing reached $3.5×10^5$ J, the maximum phase transformation overpressure within the oil gap of the bushing reached the critical pressure resistance of the lower ceramic bushing, causing it to shatter.In scenarios where the electric arc directly contacts the ceramic bushing, finite element analysis based on solid mechanics was utilized to simulate the thermal stresses exerted on the bushing. When in direct contact with the electric arc, even the lower-temperature peripheral regions were sufficient to induce thermal stresses in the ceramic bushing exceeding its tensile strength, leading to fracturing.