Electronic transformers using amorphous material

Abstract

An electronic current transformer uses an amorphous material core transformer which operates into a virtually zero ohm load by use of feedback type operational amplifiers. The output voltage is directly proportional to the primary current of the transformer. Due to the very low flux density created by virtually short circuiting the CT, the nonlinear effects and core losses are reduced substantially. An advantage of the electronic transformer is, among others, that a current transformer of reduced size may be used. Application of the amorphous alloys in small electronic current transformers and other devices appear to be justified where the design optimization can make use of (1) the lower cost expected from the amorphous alloys, or (2) their lower losses and higher permeabilities compared to the crystalline Fe-Co and Fe-Si alloys. Test results have shown that the amorphous material core transformer using an active load has somewhat lower performance than Fe-Ni (HyMu 80) <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">R</sup> core transformer of the same size but the amorphous core transformer is significantly superior to the Fe-Si core transformer.