线性放大变频电源的散热设计

摘要

鉴于线性放大变频电源易受温度影响的特性,设计了一套相应的散热系统.通过详细的推导计算,建立了变频电源主放大电路的三极管总管耗的准确计算和估算方法.并利用热阻等效电路表示系统散热路径,且给出了关于热阻的三极管结温表达式.在此基础上,由对散热器、散热风道和通风机的优化设计,研制出一套应用于线性放大变频电源的强迫风冷散热系统.通过Icepak进行热场仿真并与实际试验的结果相对比,验证了设计方案的可行性.%Given that the linear amplifying variable frequency power supply is easily affected by temperature,a heat dissipation system was developed. Both the accurate and approximate calculation methods for the total power dissipation of silicon power transistors used in the variable frequency power supply were proposed via detailed derivation. The heat flow path was described by the thermal resistance equivalent circuit,and the formula of junction temperature with respect to thermal resistance was presented. Based on the above analysis,a forced air cooling heat dissipation system which was applicable on variable frequency power supply was developed by optimizing the design of heat sink,ducts of heat dissipation and ventilator. The temperature filed of variable frequency power supply was simulated by employing Icepak. The comparison between the simulation and experiment results validate the design scheme.