Mixed D-Core With a Distributed Air Gap as an Alternative for Medium Voltage Instrument Transformers

This paper propounds a practice of using cut cores with a distributed air gap in the production of magnetic circuits for high quality medium voltage instrument transformers. It discusses utilization, for this purpose, of both grain-oriented and non-oriented electrical steel sheets of different grades, hence of considerably different characteristics and cost. The magnetic properties of the transformers were enhanced, and substantial technical and economical benefits in the manufacture of the end product were realized.