Performance evaluation of low-cost smart meter solution for IEC 61000-4-7 Class I harmonics measurements in presence of noise disturbances

This work aims at investigating the performance of a low-cost smart meter solution for harmonics measurements in the presence of disturbances. In previous works, the authors have already shown the feasibility of the considered hardware device and signal processing metrics for harmonic analysis according to IEC 61000-4-30 Class A and IEC 61000-4-7 Class I requirements. In this work, the main focus is an analysis on characterization issues of the developed case-study device, in the current standards framework. More in detail, standards for power system harmonic measurements do not consider any characterization tests to verify devices performances in the presence of disturbances. Therefore, it is very interesting to evaluate if disturbances, normally present in real cases, can determine a loss of standard compliance and thus if such phenomena are neglectable or not. For these reasons, in this work, to test the behavior of the meter device in the presence of a real signal, it has been chosen white noise, among possible disturbances that normally occur in power systems. In the paper several experimental tests are presented and discussed which show that devices can comply with the standards accuracy requirements in the absence of disturbances, but such requirements could not be fulfilled anymore in real operating conditions of smart grids. The results obtained show that it is essential to propose and develop standard test conditions that consider real operating conditions.