## 3 Literature Review  
Modern lighting appliances such as fluorescent lamps (FLs), CFLs, as well as the most popular nowadays, smart lights, including LED lamps, are sources of conducted emissions that are produced in the frequency range below 2 kHz. Several works have been published about the assessment of harmonic emissions generated by these lighting sources (the selected ones are presented below), but the issue of voltage variation over emissivity is still an open topic. To save electrical energy, the government has primarily focused on replacing incandescent lamps (ILs) with fluorescent and compact fluorescent lamps. The effects of harmonic current on FLs with different ballasts are studied in [35]. The T5 and T8 fluorescent lampswith electronic ballasts generate more distorted current waveforms than their older counterparts with electromagnetic ballasts. Selected Literature Directly Related to the Characterization of the Influence of Power Supply Conditions on the Emission of Low and High Frequency Disturbances  
For typical CFLs tested in [36], the THD in the input current is as high as 75%, while the CFL examined in [37] has a total harmonic current distortion factor (\(THD_{i}\)) equal to 67.7%. Such harmonic pollution is high and may degrade power quality noticeably. The research [38] implies that the harmonic content in the voltage signal is expected to increase as a more distorted current is drawn when connecting subsequent CFLs. The paper [39] evaluates the effect of voltage waveform distortion on the performance of CFLs supplied by constant RMS voltage and constant frequency. The experimental results show that EUT supplied by the nominal voltage with harmonic distortion factor variation up to 8% reduce efficiency of devices. Thus, the results highlight the importance of adjusting the harmonic distortion limits to reduce or prevent the increase in power loss caused by harmonic components. The LED lamps and another solid-state lighting (SSL) system impact PQ. They are studied, among others, in [40; 41; 42]. For these types of lighting, the individual current harmonic components, as well as the \(THD_{i}\) values, often exceed the limits set by the standard IEEE519 [15]. According to [42] the LED and micro\(-\)LED lamps show moderated harmonic current emissions under nominal operating conditions (sinusoidal waveform of 230 V RMS and frequency of 50 Hz) as well as under abnormal conditions such as swells, sags, notch or harmonic distortion in the voltage source. As it is indicated in [40], as a greater number of LED lamps are connected to the grid, their performance improves both in terms of power factor and harmonic pollution. According to the paper [43], the harmonic and supraharmonic current emission of individual CFLs and LEDs is impacted by supply voltage waveform distortion. Among the two types of lamps, there is a significant difference in emissivity, as well as within the same type. Using pure sinusoidal waveforms, the authors describe PQ parameters. Selected Literature Covering the Issues of Low- and High-Frequency Disturbance Emissions, Taking into Account the Issues of Concentration of the Devices and Conditions of the Point of the Connection  
In addition to lighting CFLs, measurements of other commercial and domestic appliances have been published in the literature. These include TV sets, personal computers, monitors, printers, laptops, chargers and vacuum cleaners with brush motors [4; 38; 44]. Today, these single-phase loads universally employ switch-mode power supply (SMPS) systems. To achieve a smooth DC output, these systems are usually configured with a rectifier followed by a converter. There is a high degree of nonlinearity in the input current waveform, and it is often presented to the load as short pulses.