Knowledge of the conducted emissions in the frequency range 2–150 kHz contains some gaps related to the impact of the harmonics in the supply voltage on the nature of these emissions. It can be noticed that the conducted emissions from non-sinusoidal power supplies have not been studied sufficiently, and that the impact of this distortion may be greater than the generally known results of emission tests carried out under standardized test conditions. This paper is aimed at investigating experimental cases of the influence of supply voltage waveform distortion on non-intentional emission in the range 2–150 kHz and the efficiency of power line communication based on selected PRIME (PoweRline Intelligent Metering Evolution) power line communication (PLC) technology. A series of experimental laboratory studies were investigated, representing the operation of the investigated PLC system with different types of end-user equipment (LED—Light Emitting Diode, CFL—Compact Fluorescent Lamp, induction motor with frequency converter) working under a distorted supply voltage condition obtained by the programmable power supply for different scenarios of the admissible harmonics contribution in the range 0–2 kHz. The scenarios included limits defined in standards EN 50160 and IEC 61000-4-13. The researchers used spectral analysis with a notation to emission limits, compatibility levels, and mains signalling, as well as statistics of the PLC communication. The obtained results provide important conclusions, which may be applied both in the development of the design of the appliances in question and the higher frequency emission testing methods.

Modern Smart Grids (SGs) are characterized by the simultaneous presence of time-varying and non-linear loads as well as distributed energy sources with power converters which contribute to wide spectra waveform distortions. Moreover, one of the crucial device of the SG architectures is the smart metering systems which utilize high frequencies for the power line communication (PLC) transmission. In particular, the presence of spectral components in the range of 2\div 150kHz (supraharmonics) has recently become an issue of great interest due to the interaction between widespread diffusion of high-spectral emission devices (e.g., end-user devices and converter-interfaced distributed generation systems) and power line communication systems. The complexity of these waveforms distortions makes their assessment a challenge. This paper critically analyses and compares two methods proposed in recent literature which seem particularly suitable for the spectral analysis of waveforms with wide spectra. One of the methods is based on the sliding-window discrete Fourier transform (SWDFT) referring to IEC standard harmonic estimation. The second method utilizes the sliding-window wavelet-modified ESPRIT-based method (SWWMEM). This is a companion document to a paper of the same title, Part II, where the methods are tested on synthetic and measured waveforms in terms of accuracy and computational efforts.