低压断路器主回路温度场仿真分析

Simulation of Temperature Field of Main Circuit of Low Voltage Circuit Breakers

分析了低压断路器主回路的热传递数学模型。根据动静触头的接触电阻建立了导电桥模型。基于流体相似理论和Stefan-Boltzmann定律,简化了断路器表面散热系数计算方法。考虑外接导线的散热作用,用三维有限元ANSYS软件对额定电流为200 A的断路器主回路稳态温度场分布进行仿真分析,并进行了实验验证。

Mathematical model of heat transfer for the main circuit of the low voltage circuit breaker is analyzed.Electric bridge model is established based on the contact resistance of the main contact.According to the theory of similarity for fluid and the Stefan-Boltzmann law,the calculation method of surface heat dissipation coefficient of the circuit breaker is simplified.Considering the dissipation effect of the wires,a three dimensional finite element software ANSYS is used to simulate and analyze the steady state temperature field of a circuit breaker with nominal current of 200A.Finally,the verification experiment is introduced,and the experimental results show that the simulation is correct.