A new approach to the critical induction in transformer cores

作者：Parent Guillaume^*; Penin Remi; Lecointe Jean Philippe; Brudny Jean Francois; Belgrand Thierry

来源：International Journal of Applied Electromagnetics and Mechanics, 2016, 50(4): 583-592.

DOI：10.3233/JAE-150135

• Finite element method
• grain oriented electrical steel
• magnetic cores
• transformers

The most critical areas in power transformers are their corner joints where the magnetic flux distribution presents a very high heterogeneity. This heterogeneity results from several parameters such as the geometry of the magnetic core, the anisotropy level of the electrical steel laminations and a critical induction. This paper is focused on the magnetic steel grades influence on the critical induction, adding a new parameter to those classically considered, such as the number of steps in a multiple step lap stack. Due to the difficulty to perform local measurements inside a real transformer corner, the study is performed both experimentally and by Finite Element analyses on a simplified magnetic core structure. The paper highlights that, in a corner of a core, it exists a critical induction level which depends on the magnetic steel grades and that, in a lamination, the magnetic flux density value along the Transverse Direction can be of the same order that it has along the Rolling Direction.

• 出版日期2016