Current Sharing Between Parallel Turns of a Planar Transformer: Prediction and Improvement Using a Circuit Simulation Software

Abstract

Abstract-With the increase of power needs in low voltage applications, wiring several windings in parallel to sustain large currents becomes common. This operation often has a dangerous impact on transformer reliability because additional currents, we call "circulation currents", create extra losses, generally not taken into account by analytical approaches. Yet, hot points which result from these currents can destroy the component. In planar transformers, windings are made of PCB layers and circulation currents lead to severe unbalance of current sharing between parallel layers. This paper presents an analytical method which enables currents in all layers to be evaluated using only a circuit simulation software such as Pspice ® or PSIM ® . For a designer, this method is very intuitive and fast compared with the use of fem simulations.

Leakage Inductance Analytical Calculation for Planar Components With Leakage Layers

“…These both solutions can also be discussed. Indeed, in most of power electronic converters, while power density is required, HF power transformers are made of interleaved layers to limit HF copper losses [54], [55]. Such interleaving reduces the leakage inductance.…”

Planar Magnetic Components in More Electric Aircraft: Review of Technology and Key Parameters for DC–DC Power Electronic Converter

“…In order to withstand enough current, conductors have to be connected in parallel. It has been shown in [58] that even with such connections, high frequency currents are not distributed uniformly between layers. One solution to reduce these high frequency effects, and thus the AC equivalent resistance of transformer, is to interleave copper layers.…”

Discovery of the Nearly Zero Flux Between Two Parallel Conductors in Planar Transformers

“…However, the current on each parallel conductor is usually unbalanced, as discussed in [14]. Previous research has been carried out to estimate the planar transformer AC resistance [15]- [19] and core losses [20]- [29].…”