Misinterpretations of the Instantaneous Reactive Power p-q Theory
Leszek S. Czarnecki · 2025
Abstract The Instantaneous Reactive Power p-q Theory was developed to provide theoretical fundamentals for active power filter control, with the claim that it is valid independently of the circuit situation as to structure and distortion. It claimed that it can identify the power properties of the load instantaneously, specified in terms of instantaneous active power and the instantaneous reactive power, and provide fundamentals for the filter instantaneous control. These claims are challenged in this chapter. It is demonstrated that entirely different loads such as purely resistive and purely inductive loads cannot be distinguished in terms of instantaneous active and instantaneous reactive powers. Moreover, it was demonstrated that this theory wrongly interprets the physical meaning of the instantaneous reactive power.