Power System Flicker Analysis by RMS Voltage Values and Numeric Flicker Meter Emulation

This paper introduces a new methodology of flicker analysis by using root-mean-square (rms) voltage values. The main objective is to simplify flicker assessment in a large-scale grid and propose adequate methods in order to carry out flicker analysis with general power system software. The basis of this paper is that the common flicker frequency of industrial loads is lower than 25 Hz; this makes it possible to use rms values instead of waveform samples to perform flicker computation. The researches are focused on the following three key points in flicker analysis: 1) fast voltage change-dependent distribution load model used for flicker propagation study, 2) IEC 61000-4-15 flicker meter emulators, and 3) simplified dynamic flicker load models. The studied load models and flicker meter emulators have been integrated in power-quality simulation software with the electromechanical transient analysis module. Field measurements have been used to verify and support the proposed methodology. Different case studies show that this approach gives satisfied results in flicker assessment and flicker mitigation. It is also used by utilities to perform flicker assessment prior to the connection of a disturbance load.