无功功率教学新探

New Approach to Teaching of Reactive Power

本文试图提出一种无功功率的教学方法,使无功功率的定义、物理解释与有功功率保持逻辑上的一致,同时也使无功功率与其它功率概念的联系变得清晰明确。我们在教学中,首先定义旋转电流相量,然后将其与瞬时电压相乘得到复数瞬时功率,最后由复数瞬时功率在一个周期内的平均值即得到无功功率的定义。本教学方法的优势在于:新的无功功率定义在形式上与有功功率统一,与现行无功功率的教学内容没有冲突,且更强调无功功率的功率含义。

This paper tries to develop a method for teaching reactive power in order to keep the definition of reactive power consistent logically with that of active power and to make relationship between reactive power and other power more clear. Rotating current phasor is defined firstly. Complex instantaneous power is defined with the product of instantaneous voltage and complex instantaneous current secondly. Finally reactive power can be obtained by taking average value of complex instantaneous power. The new definition of reactive power has same features with active power and emphasizes meaning of power instead of energy. It is helpful for the teaching of circuit course.