An Accurate Analytical Method for Leakage Inductance Calculation of Shell-Type Transformers With Rectangular Windings
Journal article, 2021

This paper presents an accurate analytical method for calculating the leakage inductance of shell-type E-core transformers with rectangular windings. For this purpose, first, an expression for calculating the leakage inductance per unit length inside the core window considering the core walls as the flux-normal boundary condition is derived. Then, a new accurate method for determining the Mean Length of Turns (MLT) based on the total stored energy is presented. The MLT is needed for the leakage inductance calculation using 2-D methods. By dividing the MLT into three partial lengths and calculating the corresponding leakage inductances using three different core window arrangements, the effect of core structure on the total leakage inductance is considered. The method is verified by 3-D FEM simulations as well as the leakage inductance measurements on two different fabricated transformer prototypes. The superiority of the method is also confirmed by comparisons with the previous analytical approaches. The proposed method enables the leakage inductance calculation with an error less than 1%, compared to the 3-D FEM results. Using the presented method, the leakage inductance calculations can be performed rapidly and accurately in the design stage without the need for time-consuming 3-D FEM simulations.

Finite element analysis

Leakage inductance

Boundary conditions

shell-type transformer




Transformer cores

Fourier series



Morteza Eslamian

University of Zanjan

Mohammad Kharezy

RISE Research Institutes of Sweden

Torbjörn Thiringer

Chalmers, Electrical Engineering, Electric Power Engineering, Electrical Machines and Power Electronics

IEEE Access

2169-3536 (ISSN)

Vol. 9 72647-72660

Subject Categories

Applied Mechanics

Theoretical Chemistry

Building Technologies



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Latest update

6/1/2021 1