Abstract :
For almost 50 years, step type voltage regulators have used tap changing mechanisms which arc under oil during tap changes. Although this approach has proven itself over the years and has been well accepted in the utility industry, there are several advantages to eliminating the arcing nature of these tap changers. One such approach, using thyristors to divert current, has been developed and is in field use today. The background behind this development, how this mechanism actually operates, and the advantages of this new technology over conventional methods are discussed.
