#### Title

On some misinterpretations of the instantaneous reactive power p-q theory

#### Document Type

Article

#### Publication Date

5-1-2004

#### Abstract

The main features of the instantaneous reactive power (IRP) p-q Theory, considered as a power theory of three-phase systems, are analyzed in this paper using the theory of the currents' physical components (CPC). This analysis shows that the p and q powers are not associated with separate power phenomena, but with multiple phenomena. Moreover, the results of the IRP p-q Theory contradict some common interpretations of power phenomena in three-phase circuits. Namely, according to the IRP p-q Theory the instantaneous reactive current can occur even if a load has zero reactive power, Q. Similarly, the instantaneous active current can occur even if a load has zero active power, P. Moreover, these two currents in circuits with a sinusoidal supply voltage can be nonsinusoidal even if there is no source of current distortion in the load. The analysis shows that a pair of values of instantaneous active and reactive p and q powers does not enable us to draw any conclusion with respect to the power properties of three-phase unbalanced loads even in a sinusoidal situation. Thus, the Instantaneous Reactive Power p-q Theory does not identify power properties of such loads instantaneously. This conclusion may have an importance for control algorithms of active power filters. The paper reveals the relationship between the p and q powers and the active, reactive and unbalanced powers, P, Q, and D and specifies the required energy storage capability of active power filters operated under sinusoidal unbalanced conditions.

#### Publication Source (Journal or Book title)

IEEE Transactions on Power Electronics

#### First Page

828

#### Last Page

836

#### Recommended Citation

Czarnecki, L.
(2004). On some misinterpretations of the instantaneous reactive power p-q theory.* IEEE Transactions on Power Electronics**, 19* (3), 828-836.
https://doi.org/10.1109/TPEL.2004.826500