On the suitability of compressive sampling for the measurement of electrical power quality

Abstract

The deeper interconnection and the increasing presence of active devices on the electrical networks is raising many issues concerning with the monitoring of Power Quality phenomena. Voltage parameters related to the supply of electricity and current parameters related to the working of electrical apparatuses have to be monitored as accurately as possible. To this aim specific international standards impose strict measurement methods and complex measurement instrument architectures, usually based on the computation of real time Fast Fourier Transforms, to be adopted for the purpose. In particular, considering poly-phase systems, four currents and four voltages have to be detected, synchronized, measured and analyzed with good accuracy and spectral resolution. This imposes to the measurement the calculation of eight FFTs in a very short time. These requirements conflicts with the need of cost-effective measurement instruments required by spread and distributed monitoring systems in many points of the electrical plant. To face this issues this paper proposes the study and the tuning of compressive sampling (CS) techniques capable of assuring reliable reconstruction of the signal of interest from very low acquired samples. In particular, to make the CS use more feasible, the authors have also exploited some peculiarities of the CS approach in order to reduce the computational burden usually associated with the mere application of its acquisition and reconstruction protocol. Preliminary results confirm the applicability of the proposed solution.