ABSTRACT
Today, both the IEEE term “load tap changer (LTC)” and the IEC term “on-load tap changer (OLTC)” as well as the term “de-energized tap changer (DETC)” and the IEC term “o›-circuit tap changer (OCTC)”are in the terminology of international standards, but the terms “load tap changer (LTC)” and “de-energized tap changer (DETC)” are used primarily in this chapter. Tap changers are one of the indispensable components for the regulation of power transformers used in electrical energy networks and industrial application. is contribution explains the technological developments of DETCs, resistor-type LTCs as well as of reactor-type LTCs. e general switching principles for LTCs are discussed, and applications of LTCs are introduced. Today’s design concepts of LTCs are described including the new generation of vacuum-type LTCs. e vacuum switching technology-used in LTCs-is the “state-of-the-art” design at the present time and for the foreseeable future. Examples of LTC designs and the associated switching principles show the variety of the use of vacuum interrupters. Advanced smart control technologies are presented for single transformer control as well as paralleling of transformers.
