Distortion power in systems with nonsinusoidal voltage

The ‘distortion power’ DB, also termed ‘deformation power’, is one of the fundamental power quantities in circuits with nonsinusoidal voltages and currents, and power properties of such circuits are often specified in terms of this power. Unfortunately, it was introduced to the power theory of nonsinusoidal circuits because of substantial misinterpretation of these properties. The notion of ‘distortion power’ and its relation to the waveforms distortion is the main subject of this paper. It is shown that the necessary condition for the lack of waveforms distortion is in the contradiction to such a condition for the ‘distortion power’ zero value. Therefore, its value is not a measure of the waveforms distortion effect on the source apparent power S. Thus, this power should not be used in the apparent power equation of the source. Also it is shown that the quantity termed an ‘active distortion power’ has a misleading name and was identified earlier as a scattered power.