The waveform distortion interactions and time-varying behavior in electric railway power systems (ERPS) are explored in this paper by investigating measurements from a traction converter station. The paper proposes a methodology aimed at contributing to three aspects: screening detailed measurements with high resolution in time and frequency, comprehensively assessing waveform distortion parameters of the system, and developing a time-varying framework to assess waveform distortion interactions and sub-1-min variations in the railway grid. Specific focus is given to identifying disturbance sources and patterns during operation, including limitations of traditional methodologies based on aggregated values and addressing the challenges posed by the differences between the two electromagnetic environments (railway grid and public grid). The results propose new indices ( z-WDSV,z-WDSV_w ) for evaluating waveform distortion in ERPS, highlighting the suitability of the methodology for assessing time-varying interactions and probabilistic aspects. The proposed framework can determine and quantify the frequency-domain components impacted by the operation of vehicles in the traction sections. Additionally, the limitation of longer measurement intervals is confirmed by the relationship between the aggregated value and variance due to the rapid variation caused by rolling stock operations. Other aspects of mechanisms involving waveform distortion on both sides of the traction converter station are discussed.

This paper will present a case study where light in anoffice building is disturbed and do not function properly.From measurements it is shown that a UPS system iscausing distortions. One lamp from the office wasbrought to laboratory where the distortions was repeatedand subjected to the lamp. When doing so the lampshowed the same immunity problem.

The work presents measurements of harmonics and interharmonics from a modern wind turbine over a period of several days, using a conventional power quality monitor. A statistical study has been performed to present the characteristics of the emission during the measurement. A variation of emission has been observed, especially for interharmonics within certain low-frequency bands and for the switching frequency. Multiple relations between voltage and current components have been presented, as well as multiple relations between the emission and the active-power production. Generally, harmonics are independent of the active-power, whereas interharmonics are dependent on it.

This paper presents the results of a set of measurements to study changes in voltage harmonic emission in LV grid due to the introduction of energy-efficient lamps. The paper involves measurements in an urban area performed in the north of Sweden. Measurements of voltage harmonic were performed before and after replacing all existing (mainly incandescent) lamps with LED lamps in all 12 houses belonging to the same urban area. The total power of all lamps was reduced from approximately 2300 W to 450 W, per house. All new lamps were low-power-factor lamps. In this paper it has only been shown the results for two individual houses over the twelve that changed their lamps. Those results are then compared with the standard EN 50160 in order to foresee the voltage impact after changing to LED lamps. © 2014, European Association for the Development of Renewable Energy, Environment and Power Quality (EA4EPQ).

With increasing amounts of wind power connected, the power system is impacted in a number of ways. In this paper, the emphasis is on one of those impacts: the harmonic and interharmonic emission from wind-power installations. The emission of individual wind turbines as well as from a wind park has been studied. The spectrum as a function of active-power has been studied. Various trends of emission according to the output power have been presented. For four modern wind turbines estimations have been done on the impact on the grid for each harmonic and interharmonic subgroup. The primary emission from a complete windpark due to the emission from the turbines has been analyzed

This paper presents harmonic measurements from three individual wind turbines (2 and 2.5MW size). Both harmonics and interharmonics have been evaluated, especially with reference to variations in the active-power production. The overall spectra reveal that, emission components may occur at any frequency and not only at odd harmonics. Interharmonics and even harmonics emitted from wind turbines are relatively high. Individual frequency components depend on the power production in dierent ways: characteristic harmonics are independent of power; interharmonics show a strong correlation with power; other harmonic and interharmonic components present various patterns. It is concluded that the power production is not the only factor determining the current emission of a wind energy conversion system.

To save energy, many new buildings have modern energy saving lighting installed. In large department or grocery stores the use of fluorescent lamps powered by high frequency electronic ballast is common. There are however consistent reports of large numbers of failures of the electronic ballast of these lamps. The failures of the electronic ballast are due to high temperature or bad power quality. But neither of these reasons has been confirmed as the cause. This paper discusses in general the lifetime of electronic ballast. The paper also presents detailed analysis of results from measurement performed in a grocery store where high instances of failure have been observed. Both temperature and power quality in the harmonic range and 2 to 150 kHz have been included in the measurements