The Physical Meaning of Reactive Power and Distortion Power

The phrase "physical meaning" has been used in electrical engineering for well over a century. During this time, it has apparently not been defined, and about half the time it is used it is in order to say that something does not have physical meaning. The remaining half the time the phrase is used, the purpose is often to support a viewpoint that is incorrect. This paper explores what physical meaning can mean when applied to quantities of interest in power engineering: particularly reactive power and Distortion Power. The paper shows that the phrase does not apply to the results of measurements of reactive power-it is misleading to assert that this quantity has physical meaning. However, it does apply to Distortion Power, which is shown to have a physical meaning: it is always zero.