This paper presents a comparison of measurement methods for current and voltage distortion in low voltage networks in the frequency range from 2 kHz to 150 kHz (supraharmonics). The comparison encompasses the methods informatively described in IEC and CISPR international standards, as well as other innovative techniques presented in the literature. The presented work is carried out within a novel framework that includes advanced and complex synthetic test signals, as well as real grid recordings, that allow an accurate comparison of the performance of the tested methods. Specifically designed indices are employed to characterize the accuracy of the tested methods in the frequency and amplitude assessment. In light of that, strengths and weaknesses of the methods are identified. The results of this paper contribute to the ongoing standardization work carried out by the IEC SC77A/WG9 with the purpose of defining a normative measurement method suitable for assessing grid disturbance levels in the range from 2 kHz to 150 kHz.

This paper introduces a new method for the simultaneous measurement of harmonic and supraharmonic distortion with improved robustness against amplitude and power frequency deviations. The proposed algorithm is based on wavelet analysis and it is designed to analyze a detect-all=true10 cycles measurement interval, something crucial when implementing methods to measure harmonic and supraharmonic content according to the IEC 61000-4-7 standard. Discrete Fourier Transform (DFT)-based methods, instead, must analyze a fixed detect-all=true200 interval in order to avoid apparent shifts of the supraharmonic frequency components. The results of the experimental measurements presented in the paper show that the DFT-based methodology suggested in the IEC 61000-4-7 standard produces results affected by the value of the power frequency and amplitude while the proposed method, instead, is insensitive to them. This feature also removes the need of a previous high pass filtering stage, required for the IEC method. Moreover, the proposed method has the additional advantage of working on the same measurement interval to calculate both harmonics and supraharmonics, which reduces the complexity of data handling by avoiding multithreaded Data Acquisition (DAQ) operations.

This study proposes a novel measurement method to assess the disturbances in the electrical grid for the CISPR Band A (9–150 kHz), as no normative grid measurement method for these frequencies exists yet. Compatibility levels (CL) in IEC 61000-2-2 in this frequency range are defined based on the CISPR 16-1-1 method using the quasi-peak (QP) detector. However, this method is not directly applicable for grid measurements as it was originally designed for laboratory conditions and for measuring radio disturbances and immunity. The method proposed in this article (Light-QP method) overcomes these limitations, along with lower complexity, computational burden, and memory requirements than CISPR 16-1-1. The Light-QP method uses a digital QP detector that processes root mean square (rms) values of spectral components, calculated by adapting the IEC 61000-4-7 standard to the CISPR Band A. The proposed Light-QP method is applied to real measurements from a low-voltage (LV) distribution grid and compared to the QP outputs from a digital implementation of the CISPR 16-1-1 method. The results are comparable and can be used for assessment against CL. The Light-QP method has been presented to IEC SC77A/WG9 for its potential inclusion as a normative measurement method in a new version of the IEC 61000-4-30 standard.

The purpose of the present paper is to evaluate the sensitivity of modern lighting technologies to different types of RVCs. In order to do that, 27 modern lamps—mainly LED—have been subjected to real RVCs and their response has been assessed. The detection of RVCs on the grid has been performed according to the IEC 61000-4-30 detection method, while the response of the lamps has been measured with a light flickermeter and characterized using the instantaneous flicker perception, as defined in IEC 61000-4-15. The obtained results show a high dispersion in the response of the modern lighting technologies and high values of flicker perception, although with a lower sensitivity than the incandescent lamp. The results led the authors to propose the definition of a new immunity test to be added to the lamp immunity protocol IEC TR-61547-1, to ensure that newly produced lamps cause limited irritation to grid users.