A Adaptive Supraharmonic Grouping Method Based on Iterative Threshold Searching

Supraharmonics with 2-150kHz frequency range are generated mainly from modern power electronic devices. IEC 61000-4-30 has recommended measurement methods with constant frequency resolution of 200Hz or 2kHz. Since the supraharmonic spectrum is sparsely distributed and the amplitudes are high at associated switching frequency and its integral multiples, thus harmonic grouping is essential for precise measurement and for supraharmonic source tracing. This paper proposed an adaptive harmonic grouping method based on iterative threshold searching strategy, combining with empirical criteria. Two sampling datasets from simulation are used for verification. The grouping results showed that the proposed method is able to group spectrum reasonably and capture the central frequencies.