Research On Flicker Parameters Measurement Technique And Application

With the development of industrial level and the improvement of people life quality, electric users have more and more high expectation for power supply quality. High-power fluctuated electric loads increasing day by day cause voltage fluctuation and flicker, which influence seriously power quality of electric network. According to International Electrotechnical Commission (IEC) relevant standard, voltage fluctuation and flicker have become the important index for weighing power quality, research and application of flicker parameters measurement attract more and more attention of various countries.This thesis introduces the basic conception of voltage fluctuation and flicker, analyzes the source and influence of flicker, and states the important meaning of flicker parameters measurement; And the thesis expounds detection methods of current voltage fluctuation in the principle, characteristic, application scope, and analyzes present calculation technology and deficiency; Through research on the standard IEC868 and IEC61000-4-15, this thesis further investigates FFT-based flicker value calculation methods on the basis of flicker measurement block diagram recommended by IEC. Following IEC measurement principle, through simplifying flicker signal processing, we can reduce greatly calculative amount of this method and improve obviously computational speed, and this method can be realized simply and conveniently. With this method we can calculate out directly short time flicker value Pst by voltage square root change of bus bar, and then calculate out long time flicker value Plt; Through systems analysis to fluctuation value, frequency spectrum and power of voltage and current fluctuated signal, this thesis put forward and define a new concept of flicker power, and bring forward and set up FFT-based flicker power measurement method. And through simulation we can verifiy the exactness of this method. The proposition of flicker power concept and its measurement methods offers more overall and effective reference information for research and management of flicker.Through fully utilizing modern information treatment technology and virtual instrument technology, the author succeed in developing virtualization flicker measurement device on the basis of small amount of hardware circuit in XDZ-1 virtualization power parameters automation test system. Users use and systematical examination prove advance and accuracy of flicker measurement function part. XDZ-1System has already pass the technical identification organized by Guangxi Utilities Electric Co. in January, 2004.