Instantaneous p-q power Theory for compensating nonsinusoidal systems

Abstract

This paper presents a tutorial about compensation of nonsinusoidal systems based on the instantaneous active and reactive power theory or the p-q theory. The history related to this theory is presented and then the definitions of real, imaginary and zero-sequence powers are introduced. The physical meanings of each of these powers are explained and some basic compensation examples are shown considering different active power conditioners. It is shown that this theory can be very practical for understanding problems due to nonsinusoidal voltages or currents. It is especially interesting for the design of power conditioners for three-wire or four-wire three-phase system with or without distortions in voltages and currents.