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access icon free Reduction of leakage inductance and AC resistance of planar transformers by optimising the current distribution

© The Institution of Engineering and Technology
Received 16/05/2017, Accepted 30/10/2017, Revised 25/09/2017, Published 03/11/2017

Planar transformers (PTs) are becoming increasingly popular in high-power density, high-frequency SMPS in recent years due to their unique advantages including low profile structures and excellent thermal properties. This study focuses on detailed investigation of the effects of coil current distribution within each winding layer on leakage inductance and AC resistance of a PT, and an analytical derivation based on variational method is given. Then the optimal current distribution is proposed and verified through 3D finite element analysis simulation and physical experiments. The results show that the leakage inductance and AC resistance can be reduced further by optimising the current distribution. Accordingly, a practical implementation method is proposed to control the current distribution within a winding layer by adjusting the widths of conductors.

Inspec keywords: conductors (electric); electric current control; transformer windings; finite element analysis; magnetic leakage; optimisation; inductance

Other keywords: AC resistance reduction; high-power density; winding layer; high-frequency SMPS; 3D finite element analysis simulation; variational method; coil current distribution; low profile structures; physical experiments; planar transformers; thermal properties; current distribution control; conductors width adjustment; current distribution optimisation; leakage inductance reduction

Subjects: Optimisation techniques; Inductors and transformers; Finite element analysis; Optimisation techniques; Control of electric power systems; Finite element analysis; Current control; Magnetic materials; Conductors

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