A. Bień

Comparative tests of flickermeters

It can be shown that different digital flickermeters implementations that meet the performance tests defined in IEC 61000-4-15 can still disagree significantly in some actual measurements. This paper is intended to apply a set of tests proposed by UIE/CIGRE WG 2 to ensure that implementation is correct and different meters will agree with all types of actual measurements. The main objectives are: (i) test how well flickermeters comply with IEC standards, (ii) provide a reproducible method of testing so that tests can be repeated at another time with any flickermeter designed to IEC 61000-4-15, (iii) prepare test data and test programs for distribution to potential flickermeter manufacturers, (iv) gain knowledge about additional functionality or limitations provided by the tested flickermeters. The tests have been performed using five instruments.

The influence of a phase change in the measured voltage on flickermeter response

The influence of a phase change in the measured voltage on a flickermeter response is discussed. The paper shows that the instant of occurrence of a phase change can influence the flickermeter response if the disturbance occurs just before the termination of the ten-minute Pst evaluation interval.

Application of neural networks to voltage fluctuations measurement-a proposal for a new flickermeter

This paper discusses the standard IEC 61000-4-15 flickermeter design and the principle of measuring voltage fluctuations based on human eye-brain perception. The conception of a neural network performs the measuring part of a flicker meter. The flicker is developed with Matlab environment to set input and output signals, which is taken as the training set for the neural network. The simulation results are obtained from the estimation of the input signal envelope employed to the processes of training the neural network.

Analysis of voltage disturbances caused by simultaneous amplitude and phase modulation in electric power network

Voltage distortions and disturbances in power network are an important power quality factor. Usually in literature phase disturbances are neglected and only amplitude distortions are discussed. Amplitude disturbances are interpreted as amplitude modulation (AM) of main 50 Hz frequency and considered to be the only reason of light flicker. Standard flicker measurement method is based under two not fulfilled assumptions: 1) AM with modulating frequency lower then 50 Hz carrier frequency and 2) constant carrier frequency. In the article detailed analysis of possible disturbances and it sources is presented. It is shown that AM and narrow band PM (phase modulation) take place in power network simultaneously and those two modulations interact with each other. Theoretical results are verified by field experiment.