Summary: | 碩士 === 國立中正大學 === 電機工程研究所 === 101 === Voltage fluctuation can be regarded as the primary cause of flicker and is the time variation of the reactive power component of fluctuating loads. Such loads typically include, for example, arc furnaces, rolling mill drives, and welders. Moreover, flicker may result in the luminance variations of lamps, which can cause uncomfortable and irritative perception or even give rise to vision problems.
Many countries have established or adopted the regulation standards to limit the flicker levels. Currently, IEC flickermeter standard is the one used most widely. However, is utilized in Taiwan to evaluate the flicker. With the global trend, the implementation of IEC standard is necessary and is with indices of Pst and Plt that are calculated based on statistical analysis to estimate the flicker severity.
IEC Standard 61000-4-15 gives functional and design specifications for a flickermeter which is the simulation process based on the response of human’s visual perception to the fluctuation of light. The simulation process, which includes square multiplier, band-pass filter, weighting filter, first-order smoothing filter and statistic calculation of instantaneous flicker level curve (IFL), can effectively estimates Pst value to assess the severity of voltage flicker.
In order to verify the digital measurement scheme of IEC 61000-4-15, a DSP-based digital flickermeter is developed. According to the functions and design criteria suggested by IEC, an analog model of the flickermeter is developed and simulated with MATLAB, Simulink, and Code Composer Studio. Finally, the developed flickermeter will be applied to perform actual measurement based on IEC Standard 61000-4-15 test procedures to validate its usefulness.
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