Effects of voltage sags, swell and other disturbances on electrical equipment and their economic implications

Poor power quality has come to stay in most parts of the world. In most part of Africa, especially in Nigeria, it is almost normal not to have good clean power free from disturbances. If power equipment and loads could talk or express feelings, I am sure they would have made a big protest against the great injustice imposed on them. A survey was carried out amongst 15 multi-national companies in southwest Nigeria to ascertain the cause(s) and effects of poor power quality on electrical equipment and its economic implications. The survey revealed that 9 out of 15 of those companies loose an average of 5 variable speed (AC) drives every year owing to poor power quality. It also revealed that the most common disturbances faced are voltage sag and swell. This paper is aimed at stating some of the predominant power disturbance parameters, their sources and causes, the effect they have on electrical equipment, and their cost/economic implications. It also identifies some practical solutions and methods of addressing poor power quality issues