全尺寸高压开关柜电缆绝缘故障电致燃烧试验研究及机理分析

Research and Mechanism Analysis of Electrically Induced Combustion Test Caused by Insulation Faults of Cable for Full-size High-voltage Switchgear Cabinet

由于开关柜的封闭特性,长期以来研究人员对于开关柜内火灾发展的时空演变规律缺乏认知,对电缆放电能否引燃、如何燃烧有争议,针对性的防范措施缺乏依据。燃烧试验难度大,全尺寸试验难以开展。文中针对高压开关柜电缆单相接地短路引发火灾的过程开展研究。搭建全尺寸试验平台,研究掌握了电缆短路起火过程中开关柜内外以及电缆外皮的温度分布情况。开展了多物理场仿真研究,构建了开关柜起火模型,掌握了火灾蔓延规律。基于仿真和试验结果对电缆电致燃烧过程中电缆材料分解过程及材料分解对燃烧的影响进行了分析。通过上述研究,掌握了高压开关柜电缆绝缘故障燃烧机理,掌握了电缆外皮温度可以很好的反应开关柜内部故障温度,为开关柜火灾预防奠定了基础。

For a long time,the researchers are lack of understanding the spatiotemporal evolution of the fire develop-ment in switchgear cabinet due to the enclosed characteristic of the switchgear cabinet.There is a dispute about weather the cable discharge can ignite and how to combust and targeted prevention measures are lack of basis.It is difficult to carry out full-scale test due to large difficulty in the combustion test.In this paper,the fire process caused by short-circuit of single-phase grounding cable of HV switchgear cabinet is studied.A full-scale test platform is set up to study and master the temperature distribution inside and outside the switchgear cabinet as well as the cable sheath in the short circuit fire process.The research of multi-physics field simulation is performed,the ignition model of the switchgear cabinet is constructed and the fire spreading is mastered.Based on the simulation and test results,the cable material decomposition process and the influence of material decomposition on the combustion are ana-lyzed.Through the research mentioned above,the combustion mechanism of insulation fault of cable for HV switch-gear cabinet is mastered.The cable sheath temperature can well reflect the internal fault temperature of the switch-gear cabinet,which lays a foundation for the fire prevention of the switchgear cabinet.