This guide is intended for use in establishing a methodology to evaluate expected long-term performance of infrequently operated switch contacts used within insulating liquid-immersed transformers. These switch contacts are typically found in de-energized tapchangers, dual voltage switches, reversing switches, on-load tapchangers, and step-voltage regulators, but the test might possibly be used to evaluate any contact that is used in insulating liquids with similar operating characteristics and within similar environments.
This guide specifies the technical requirements for the thyristor bypass switch (TBS) used in a unified power flow controller (UPFC), including TBS structure, layout, function, performance, control, protection, monitoring, and communication interface technology. This guide also specifies testing methods that can be used as references and guidelines for design, function and performance inspection, testing, and acceptance of equipment.