Supraharmonics in-situ measurements in distribution networks. An experimental case-study analysis of Standards-based metrics

This work presents an experimental on-field case-study analysis of Standards-based metrics for supraharmonics (SHs) measurements in distribution networks. IEC 61000-4-30 FFT-based metrics, with some proposed modifications, are compared with measurements according with CISPR 16-1-2, using as reference IEC 61000-2-2 and IEC 61000-2-4 for SHs emissions limits in 9-150 kHz frequency range. Measurements have been carried out on a commercial bidirectional power electronic converter (ac/dc and dc/ac) with a battery storage system, operating in both charging and discharging mode and with different power levels. To investigate the feasibility of the proposed approach, the analysis is extended to both voltage and current waveforms. The obtained results show that, with some modifications, IEC 61000-4-30 FFT-based metrics can provide information comparable with CISPR-based measurements, in the perspective of preliminary in-situ evaluation of SHs emissions levels and without the need of sophisticated on-field instrumentation.