关于无功功率的讨论

Discussion on Reactive Power

本文针对电路教学实践,对无功功率的物理意义、无功功率的大小和符号以及无功功率与正弦稳态瞬时功率之间的关系进行了讨论,指出平均功率是由同相电压、电流分量产生的,而正交电压、电流分量则产生无功功率,并据此导出了无功功率与正弦稳态瞬时功率之间的两种表达式。本文廓清了关于无功功率的一些模糊认识,可供讲授电路课程的教师参考。

This paper has discussed physical meaning of reactive power from the point view of circuit teaching prac- tice. The meaning of value and plus-or-minus sign of reactive power has been explained. TWO expressions between reactive power and instantaneous power have been deduced based on the fact that sinusoidal steady voltage and cur- rent produce real power when they are in phase and produce reactive power when they are orthogonal. Some vague statements on reactive power have been clarified. It is helpful for the teaching of circuit course.