Unlocked by Huaming: OLTC Course – e-lesson #3 – Reactor type OLTC
Hosted by: Raka Levi / Intermediate level
Join us on 21st May at 2 pm CET for the lesson #3 of the OLTC course!
This e-lesson focused on reactor-type on-load tap changers, providing an in-depth look at their operating principles, design features, and advantages over resistor-type tap changers. The speaker, Dr. Raha Levi, explained how reactor-type changers can operate in a bridging position, doubling the number of available tap positions. A key benefit of the reactor design is its ability to control load current and prevent damaging circulating short-circuit currents. The presentation covered various switching mechanisms, including arcing tap switches, selector and transfer switches, as well as the use of vacuum interrupters, which offer extended maintenance intervals. Detailed animations and diagrams were used to illustrate the complex switching sequences of reactor-type tap changers. The speaker also discussed testing methods, such as dynamic resistance measurement and vibro-acoustic analysis, that can help detect mechanical issues within the tap changer. Overall, the lesson offered a comprehensive technical overview of this important transformer component and the latest advancements in its design and operation.
Content of this lesson is fully vendor agnostic but it is sponsored by Huaming!
In this e-lesson you will learn of reactor type tap changers, the difference between double and single contact designs, operation of a transfer switch and arcing tap switch. Dr. Levi as one of the world’s leading experts in diagnostics of OLTC in a high voltage oil-filled power transformers, will explain principles of operation of reactor type tap changer applied to power transformers, as well as a brief preview of the future sessions.
Keywords: OLTC, transformer, preventive autotransformer
About the author
Raka Levi
Dr. Levi spent his entire career in diagnostic testing transformers and other substation apparatus, while the last 15 years dealing with tap changers. He is senior member IEEE and vice-chairman of the working group for revision of Guide for testing power transformers. Raka Levi consulted clients on all 5 continents in the field of condition assessment and substation monitoring.
