The measurement of actual apparent power and actual reactive power from the instantaneous power signals in single-phase and three-phase systems

The measurement of both electric power and energy, especially in nonsinusoidal conditions, is still an open research problem in the metrology community. Harmonic distortion, noise, transients, over-voltages, and voltage dips have increased the difficulty in achieving accurate measurements. Many nonactive power component definitions have been proposed in the literature, even if their physical interpretation poses some problems. The conventional technique for measuring the apparent power S operates by calculating the product of the root-mean-square (rms) of the voltage and current. This paper investigates the introduction of a novel definition of apparent power S and reactive power Q, starting from the processing of the instantaneous power signal, both in sinusoidal and nonsinusoidal conditions. In particular, the rms value of the instantaneous power waveform is processed to obtain the power parameters. The aim of this study is to contribute to the research concerned with the measurement of apparent power, reactive power, and power factor under nonsinusoidal conditions in single-phase and three-phase systems. Moreover, one benefit of the proposed work is that the signal processing required to implement an electric power and energy meter would be simplified.