Modification of IEC Flickermeter to Measure the Flicker Caused by Inter-Harmonics

상호고조파에 의한 플리커의 측정에 가능한 IEC 플리커미터의 설계

Now the IEC flicker measuring algorithms and its flicker index of $P_{st}$ and $P_{lt}$ are accepted internationally as standards. But it is recently found that IEC flickermeter has a main drawback that it cannot afford to detect the fluctuating patterns of voltage envelope caused by interharmonics higher than 102Hz in the 60Hz power system. This is brought about by two components of IEC flicker measuring steps, squaring and low-pass filtering. This paper presents the innate defect of IEC flickermeter and proposes a modified measuring method considering the voltage flickers by subharmonics and interharmonics.