Przemysław Otomański

Search for disturbing loads in power network with the use of voltage and current fluctuation

The paper discusses a set of the most frequently used measures of voltage fluctuation, which are useful in searching for disturbing loads. A procedure appropriate for searching the loads causing voltage fluctuation is proposed. The procedure utilizes two measures of fluctuation: Pst indicator as well as minimal and maximal values of voltages and currents. An analysis is included of four exemplary measuring results, recorded in a LV network. The effect of this analysis is a conclusion whether a disturbing load appears or not. The first Example illustrates the state in which it was possible to designate a disturbing load. The other Example shows a situation in which an unequivocal conclusion is impossible. In Examples 3 and 4 it was found that the loads under investigation are not dominant sources of voltage fluctuation. By means of the hereby analysis of measurement data the authors prove the diagnostic potential of the proposed procedure for searching for disturbing loads

Flicker Vision of Selected Light Sources

Abstract The results of the laboratory research concerning a dependence of flicker vision on voltage fluctuations are presented in the paper. The research was realized on a designed measuring stand, which included an examined light source, a voltage generator with amplitude modulation supplying the light source and a positioning system of the observer with respect to the observed surface. In this research, the following light sources were used: one incandescent lamp and four LED luminaires by different producers. The research results formulate a conclusion concerning the description of the influence of voltage fluctuations on flicker viewing for selected light sources. The research results indicate that LED luminaires are less susceptible to voltage fluctuations than incandescent bulbs and that flicker vision strongly depends on the type of LED source.

Oddziaływanie wahań napięcia na impulsowe zasilacze diod LED

The paper presents result of experimental research the interaction of input voltage fluctuation on the state of selected LED switching power supply with constant-voltage and constant-current outputs. Research was realized on the designed measuring system for voltage fluctuation reconstructed by amplitude modulation on rectangular signal for selected frequency modulation. The influence of voltage fluctuation on the state of tested power suppliers was determined with two methods: on the basis of output current waveforms (supplying LEDs) and using the subjective assessment observer by flicker vision. (Voltage fluctuation interaction on LED switching power supply). Słowa kluczowe: wahanie napięcia, dioda LED, widzenie migotania światła, jakość napięcia.