Experimental Investigation Of Light Flicker For Fluorescent Lamp Under Interharmonic

With the rapid development of power electronic technology, interharmonics wereinjected into power system increasingly, especially the extensive use of variablefrequency drivers (VFD) in power system and the increased number of massivenonlinear loads. Interharmonics will cause voltage fluctuation and flicker, and that iscausing light flicker on lamp that will impact on people’s visual comfort and workefficiency. Interharmonics make fluorescent lamp flicker visibly. Recent years, thisproblem attracted attentions of researchers and got many achievements. But at present,research about interharmonic limit standard and evaluation method based on voltageflicker are still scarcely. The study on fluorescent lamp flicker under interharmonic ismeaningful and valuable to establish the interharmonic tolerate standard.In order to conduct experimental study for flicker, In this thesis, a decomposedflickermeter model was developed by decomposing the weighting filter of IECflickermeter. Luminous flux signal acquired from experiments can be input directly intothis model to calculate the short-term severity value Pst. In this thesis, the feasibility andeffectiveness of this model was experimentally verified.The experiment system was designed and experimental facility was establishedbased on the proposed decomposed flickermeter model. The high-precision illuminancemeter is applied to acquire luminous flux signal of the compact fluorescent lamp (CFL)supplied by voltage containing interharmonics with given frequency and magnitude.Experimental studies for CFL light flicker under voltages containing interharmonicswith various magnitudes and frequencies were conducted by using the proposeddecomposed model. The short-term severity value Pstwere obtained, and therefore theinterharmonic limit curves for light flicker of compact fluorescent lamp were proposed.Analysis of interharmonic limit curve is proposed in this thesis, as well as the lawthat interharmonic threshold change with the change of frequency. The comparison ofinterharmonic limit curve of CFL with different power and brand is also made. Theexperiment of straight tube fluorescent was conduct meanwhile, and interharmonic limitcurv was also proposed, with the judgement of flicker by human eye’s observation.