Research on medium-voltage electronic transformers

The electronic transformers have a series of problems in testing and operation. This paper discusses the saturation characteristics of electronic current transformer and the temperature characteristics of electronic voltage transformer. Current transformer with nonlinear excitation characteristics usually includes a closed-core. It can not work in transient process because of core saturation. This paper analyzes the features of the current transformer with non-magnetic air gap. The principle and structure of the electronic voltage transformer based on voltage divider are introduced, and the factors affecting its temperature characteristic are analyzed. Hence, a method of temperature compensation via thermistor is presented to enhance the temperature stability of the medium-voltage electronic transformers.