Abstract

Voltage flicker is one of the most common power quality complaints reported by utility customers. The term flicker refers to visible changes in lighting intensity caused by rapid fluctuations in supply voltage. While the concept of flicker has been studied for decades, modern electrical systems contain an increasing number of loads capable of producing voltage fluctuations. These include arc furnaces, large motor starts, welders, electronically controlled heating systems, and many types of modern power electronics.

Objective measurement of flicker became possible with the development of the flickermeter defined in IEC 61000-4-15 and adopted by IEEE 1453. Many modern power quality monitors implement this signal processing chain and produce standardized flicker metrics such as Instantaneous Flicker Level (IFL), Short-Term Flicker Severity (Pst), and Long-Term Flicker Severity (Plt).

Modern analysis tools have also evolved. While earlier investigations relied on software such as ProVision to examine flicker recordings, current systems such as PQ Canvass provide cloud-based access to flicker data. In addition, artificial intelligence tools such as Merlin™ can automatically analyze recordings and assist engineers in diagnosing flicker problems.

This paper provides an overview of flicker fundamentals, the operation of the standardized flickermeter, and modern workflows for analyzing flicker using PQ Canvass and Merlin™.