Voltage Dips in Power Quality - a Brief Review

The paper is intended to be a brief review of an utmost important power quality events, namely voltage dips/sags, that determine annoyances in the normal operation of equipment, especially of the sensitive ones. After the basic definitions of power quality from the introductory section, the main sources of voltage dips, their parameters, the effects they produce, along with a few mitigation measures are addressed. The main indices quantifying the performance of power systems according to the IEEE 1564-2014 guide are consequently presented. The final section is devoted to a short analysis of several measurements performed by the author at the secondary windings of a transformer substation, in terms of time and harmonic analysis.