Power System Harmonics

Power system harmonic distortions have become a major concern of power engineers during the past few years. This is due to the increase in the number and rating of nonlinear devices connected to the power system. The main reasons for this increase are the advancement in power semiconductor switches and their application in power converters and various other electronic circuits, and the widespread use of arcing devices and electromagnetic devices. Harmonics have undesirable effects on the power system; these include possible harm to system components and customer loads, excessive losses, malfunction of control equipment and communication interference. Some of the methods used in harmonic analysis and nonlinear load modeling are discussed. Various methods of attempting to control harmonics are also mentioned, and finally the possible future trend of harmonic problems is addressed.