使用电加热器的卫星主动控温回路是一种重要的主动热控措施，通过简明扼要的机理分析建立起该主动控温过程中受控对象温度变化的动态方程，得出了稳态控温、瞬态控温两种基本的控温模式下主动控温回路电加热器功率需求的计算表达式，给出了进行主动控温回路电加热器热功率设计计算的一般流程，较详细地分析了一个具体设计算例，为卫星主动控温回路设计计算提供了简便的计算模型和方法。

Electrical heater is an important type of active thermal control methods. A dynamical equation of its control object's transient temperature change is established through principle analysis. The heating power demand calculation models at different temperature control models have been developed from the dynamical equation. The calculating flow of electrical heater's heat power has also been introduced. An active heating loop design example, which is included at the end of this paper, shows that the equations developed above can be used conveniently in satellite's active thermal control system designing and calculating.