A Discussion of Issues Related to LTC Reliability and Life Extension Opportunities During the Design or Redesign of an LTC Transformer

摘要

Load tap changers (LTCs) are among the single most expensive components in a transformer. They are also involved in many transformer failures. When buying a new transformer or considering the repair of a used transformer, certain opportunities exist to increase the reliability of the unit by reducing stresses on the LTC mechanism. In order to take advantage of these opportunities, the owner of the transformer must understand the basic principles affecting LTC operation. This paper presents a description of these principles and identifies some of the operating characteristics that can be modified during the transformer design stage in an attempt to extend the life of the LTC mechanism.