After one hundred years of development, switching technology and the transformer merge—marking the start of a new generation of power transformers.
With the introduction of vacuum technology, it became unnecessary to separate the transformer’s oil system from that of intank type tap-changer. Nevertheless, the external design of intank type tap-changers remained virtually unchanged for many years: a cylindrical oil compartment continued to separate the two oil systems. After gaining considerably experience with ECOTAP® VPA the world first integrated type tap-changer for power transformers was brought to market: the VACUTAP® VI. The first OLTC of the 3rd* tap-changer generation was developed to enable “better” transformers: Increased power density or smaller footprint of the transformer, elimination of accessories such as protective relays, dehumidifiers, and oil level indicators, and simplified integration of OLTC into the transformer are just a few of the advantages made possible by this design without oil compartment.
