VACUUM SWITCHING TECHNOLOGY IN ON-LOAD TAP-CHANGERS APPLICATION AND SERVICE

Today, mineral insulated and cooled power transformers are world wide most frequently used. The transformer oil is used by on-load tap changers not just as a medium of insulation, but also as a breaking medium during tap changing. A complex kinetic system of switches concluding one tap change sequence within about 50 ms guarantees the successful current commutation during svatching from one tap to another - gm necessary knowhow is one of the very key-competences of a manufacturer of on-load tap-changers (OLTCs). The desire to reduce considerably frequency and extent maintenance or to enable the utilization of alternative insulation, makes new switching technologies necessary. The solution with the greatest advantages - from the today's point of view - seems to be the application of vacuum interrupters as switching elements. The hermetically sealed system of the vacuum-switching element prevents any interactions with its environment. As a result no fission or decomposition products which are primarily responsible for required maintenance can arise within the insulating liquid.

کلیدواژه ها:

On- load Tap-Changers ، Transformers ، Vacuum Interrupters