Investigation and Modeling of Voltage Flicker

Power quality (PQ) has emerged as one of the most critical aspects of modern electrical networks, particularly in industrial systems where nonlinear and fluctuating loads are dominant. Among various PQ disturbances, harmonics and voltage flicker are of paramount importance due to their severe impact on equipment performance, energy efficiency, and user comfort. Harmonics originate from nonlinear devices such as converters, variable-frequency drives, and arc furnaces, while flicker is caused by low-frequency voltage amplitude modulation, typically induced by rapidly varying loads such as electric arc furnaces, welding machines, and large motor drives. This paper presents a comprehensive study on the modeling, analysis, and mitigation of voltage flicker, with emphasis on MATLAB/Simulink implementation. A timedomain flicker model was developed using a fundamental sine source and a low-frequency modulating signal to replicate real flicker phenomena. The simulation results include main voltage waveforms, envelope detection, flicker input signals, and flickermeter outputs, from which the short-term flicker severity index (𝑃𝑠𝑡) is evaluated. Furthermore, mitigation methods using FACTS devices such as SVC and STATCOM are discussed. The findings highlight the importance of accurate load modeling, the relevance of IEC 61000-4-15 measurement standards, and the effectiveness of compensators in reducing flicker severity.

کلیدواژه ها:

Power Quality ، Harmonics ، Voltage Flicker ، 𝑃𝑠𝑡 ، FACTS Devices