Processing techniques for metrological improvement of low-cost smart meter hardware solution for IEC 61000-4-7 Class I harmonics measurements

• An experimental study is presented on the feasibility of using low-cost microcontroller boards for harmonics measurements according to IEC 61000-4-7 Class I requirements. • To improve the measurement accuracy, time domain interpolation algorithms (Farrow and Lagrange polynomial) are analyzed and compared both in simulation and in experimental tests. • Interpolation and FFT algorithms are implemented in a case study microcontroller device, and different sampling and processing solutions are compared in terms of measurement accuracy, computational cost, and memory requirements in order to increase metrological ADC behavior. • The microcontroller device performances are compared with those of a more accurate PC-based instrument and errors on harmonic analysis obtained with the different solutions are compared with the IEC 61000-4-7 Class I limits. • The feasibility of harmonic analysis implementation on smart meter microcontroller devices, according to IEC 61000-4-30 Class A and IEC 61000-4-7 Class I requirements has been verified. The work investigates the feasibility of harmonic analysis implementation on smart meter microcontroller devices, according to IEC 61000-4-30 Class A and IEC 61000-4-7 Class I requirements. The final aim was to evaluate to what extent Class I harmonic analysis can be integrated into existing low-cost hardware platforms for smart metering, which normally have limited hardware features, especially concerning the ADC and the possibility of varying the sampling frequency with high resolution, according to the power system signal frequency. An extended experimental characterization is carried out on a case study device, aimed at analyzing its performances in terms of both measurement accuracy and computational burden. To increase metrological ADC behavior and decrease computational costs, sampling strategies and optimized interpolation algorithm have been implemented and tested verifying the feasibility of harmonic analysis implementation on smart meter microcontroller devices, according to IEC 61000-4-30 Class A and IEC 61000-4-7 Class I requirements.