Measurement Of Flicker And Identfication Of Flicker Source

Voltage fluctuation and flicker is one of the important indexes of electric power quality, the premise of improving and controlling flicker is testing flicker and locating flicker interference source fast and accurately. This paper studies the measurements of wind power voltage flicker and the recognition method of flicker source in complex power network.First, the basic concepts of voltage fluctuation and flicker and the causes of flicker are introduced, the common voltage fluctuation test method is analysised and compared, the flicker measurement method recommended by IEC and its digital realization method is studied. For wind farm low-frequency flicker test error, the big question to the IEC flicker measurements recommend methods were improved, the LabVIEW virtual instrument development platform was used to achieve digital flicker measurement, the flicker measurement parameters such as instantaneous flicker sensation level, short time and long time flicker severity are concluded.Second, by analyzing the flicker load voltage and current characteristics, the characteristic quantities which can effectively identify flicker source is extracted, the hazards generated by flicker source is assessed. Several kinds of typical flickermeter identification orientation method are analyzed, the fundamental problem and the required key technology to flicker source localization are discussed, a simulation analysis was carried out to verify the possibility of existing misjudgment for the correlation coefficient method in distinguishing ordinary load and flicker source load, and analyzed the causes of miscalculation, and the reason for the erroneous judgment is analyzed.Third, in view of the harmonic source and flicker source in distribution network, a kind of harmonic source and flicker source identification algorithms is presented. Through the analysis of the common connection point voltage and each load branch current waveform similarity, the ordinary load and the harmonic source and flicker source are distinguished; Then, through comparing common connection point voltage and load current changes direction, the harmonic sources and flicker source are distinguished.The distribution network with flicker source and harmonious wave source is modeled and simulated by MatLab / Simulink software, the normal linear loads identification method based on moving window approach of the maximum correlation coefficient and flicker source identification method based on voltage increment and current increment are simulated and studied. The simulation results show that the algorithm can accuratly identify flicker disturbance source, even on occasion of harmonic source and flicker source.