功率型线绕电阻器的热计算

Heating Calculating For Power Wire-wound Resistor

为了达到指导功率型线绕电阻设计和应用的目的,以能量守恒原理为基础,利用热功转换理论建立基本方程,采用数学分析的方法得出功率型线绕电阻器在恒定功率作用下表面温升与时间的函数关系。通过对结果的分析获得电阻热平衡状态下的表面温升及达到热平衡的时间常数。确定了通过试验和理论计算相结合获得综合散热系数的方法,并通过实验验证得出了理论与实际相符的结论,从而建立了功率型线绕电阻器恒定功率下的热模型。

To achieve the design and application of the power wire wound resistor, a basal equation was established by using the power-to-heat conversion theory based on the principle of energy conservation. As for the power wire-wound resistor, the function ralation between surface temprature rise and time under the action of invariablenes power or pulse power was obtained with the method of mathematics analysis. The time constants of the surface temprature rise in the heat balance state of the resistor and the achievement of thermal balance are obtained by analysing the results obtained above. The method to achieve the composite coefficient of hea transfer is confirmed by experiment and theoretical calculation, with which the thermal model of the power wire-wound resistor is established under the constant power.