The fundamental concepts of power theories for single-phase and three-phase voltages and currents: Part 27 in a series of tutorials on instrumentation and measurement

In this paper, the author discussed the generalization of non-active, reactive and apparent power concepts to nonstandard situations. Although the most general case has not been dealt with for lack of space, the main message should be clear: the generalization of the classical concepts is not straightforward. Measuring these quantities in non-standard (distorted, unbalanced and polyphase) situations is not just a matter of accuracy, but first requires clarification of which physical properties to characterize to arrive at the definition of the concepts, and only then suitable measurement techniques can be developed.