Basic Theory and Practical Considerations in a Current Transformer

Author

Yahyavi, Mehdi ; Brojeni, Farshid ; Vaziri, Mohammad

fYear

2007

fDate

24-28 June 2007

Firstpage

1

Lastpage

8

Abstract

In this paper, a brief discussion about the theory and the governing fundamentals of a current transformer (CT) is presented. A classical modeling of the CT identifying the essential parameters is introduced and the basic formulas relating the CT voltage, current, burden, and their relationships have been discussed. Practical procedures for measuring the various burdens connected to a typical distribution circuits are analyzed. ANSI and IEC standards regarding CT types, accuracy class, characteristics, and burdens are compared. CT saturation has been addressed and examples showing simple analyses have been provided. Dynamic characteristics of a CT for generalized transient analyses have been introduced. Concluding remarks regarding practical approximations and guiding principles have been presented.

Keywords

current transformers; machine protection; transient analysis; ANSI standards; IEC standards; current transformer; distribution circuits; generalized transient analysis; Circuit faults; Current measurement; Current transformers; Fault currents; IEC standards; Knee; Magnetic cores; Saturation magnetization; Transformer cores; Voltage; ANSI; CT; CT Burden; Characteristics; Current Transformer; Excitation; IEC; Knee Point; Saturation;

fLanguage

English

Publisher

ieee

Conference_Titel

Power Engineering Society General Meeting, 2007. IEEE

Conference_Location

Tampa, FL

ISSN

1932-5517

Print_ISBN

1-4244-1296-X

Electronic_ISBN

1932-5517

Type

conf

DOI

10.1109/PES.2007.385922

Filename

4275688