基于Comsol Multiphysics喷射式熔断器弧前时间数值仿真

Numerical Simulation of Pre-Arcing Time of Expulsion Fuses Based on Comsol Multiphysics

弧前时间是熔断器开断特性的重要参数指标,为此以12kV/6A某型号熔断器为研究对象,搭建三维简化模型,基于有限元理论建立熔断件热电耦合数学模型,采用有限元仿真软件对模型进行仿真求解。通过加载短路大电流研究熔断件温度变化,选取熔断件熔体最高温度达到熔点作为弧前时间的判据,并随着短路电流的减小,提出熔体熔化汽化点为弧前时间参考点,最后验证仿真模型及选取弧前时间参考点的可行性,为产品研发和改进提供方向性指导。

The pre-arcing time-current characteristic is an important parameter index for studying the breaking characteristics of the fuse.A 12 kV/6 Afuse was used as the research object,the three-dimensional simplified model was constructed.The thermoelectric coupling mathematical model of the fuse element based on the finite element theory and the model was simulated and solved by finite element software.Through study on temperature changes of fuse pieces by loading short circuit and high current,the time interval before melt maximum temperature of the fuse was selected as the boundary conditions of pre-arcing time.With the reduction of the short-circuit current,the melting vaporization point was set as the reference point for the pre-arcing time.Finally,the simulation model and the feasibility of choosing the reference point of pre-arc time was verified to provide directional guidance for product development and improvement.