Design of novel structure current transformer with shielding coils for overcoming the saturation of core

• Published in: IEEE transactions on magnetics Vol. 42; no. 4; pp. 1431 - 1434
• Main Authors: Haiyu Yu, Haiyu Yu, Jiansheng Yuan, Jiansheng Yuan, Jun Zou, Jun Zou
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.04.2006; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Coils; Cross-disciplinary physics: materials science; rheology; Current transformer; Current transformers; Design engineering; electromagnetic shielding; Exact sciences and technology; Joining; Magnetic analysis; Magnetic cores; Magnetic field measurement; Magnetic fields; Magnetism; Materials science; nonlinear; Other topics in materials science; Phase current; Physics; Power system analysis computing; Power system measurements; Power system protection; Power system reliability; Saturation; Shielding; Transformer cores; Transformers; Coils; Design; saturation; Proceedings; Current transformer; Calculus; Shielding; Electromagnetic shielding; nonlinear; Magnetic properties
• ISSN: 0018-9464; 1941-0069
• DOI: 10.1109/TMAG.2006.872478

The core saturation of current transformers is one of the key obstructions in the development of highly reliable protective approaches and devices of power systems. A novel structure current transformer with shielding coils is introduced and analyzed in this paper. The coils are enwound outside the measurement winding of the current transformer, and each couple of coils are located at the opposite position relative to the diameter of the core, and connected in opposed-polarity. With the opposed-polarity connecting coils the magnetic field in the core produced by its adjacent phase current in a three-phase system can be shielded, so that the core saturation can be avoided. However, the coils do not influence the main magnetic flux that is caused only by the same phase current