The Measurement of the RMS Instantaneous Power for the Power Distortion Evaluation

Abstract

The measurement of both electric power and energy, especially in non sinusoidal conditions, is today a still open research problem in the metrology community. Harmonic distortion, noise, transients, over-voltages and voltage dips have increased the difficulty in achieving accurate measurements. Besides, many of non-active power component definitions that have been proposed cannot be implemented in the traditional electro-mechanical or solid-state meters. This paper goes on to investigate about the possibility to process the instantaneous power signal when harmonics are likely to occur. The intent is not to resolve theoretical controversies, but instead to investigate about the possibility to easily process the instantaneous power signal in order to reduce the meter cost. Specifically, in the paper the measurement of a power parameter A*, which is sensible to the harmonic interferences with the fundamental component of the instantaneous power, is proposed. This parameter can be adopted for the development of a simplified single-phase electric energy meter able to operate in non sinusoidal conditions and to supply distortion information. Additionally, some simulation results are proposed, to confirm the applicability of the proposed measurement technique.