Multiphase LLC Transformer Layout for High-Current Loss Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Transformers designed for LLC resonant converters are not optimized for high currents, leading to higher losses in applications requiring large currents.
Innovation Solution
An N-phase transformer assembly with a soft-magnetic core structure featuring air gaps and bijective primary and secondary windings, designed to provide resonant and magnetizing inductances, and secondary windings that pass through openings to reduce length and Joule heating, using soft-magnetic materials like ferrites to enhance leakage inductance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If transformers are designed for LLC resonant converters with conventional winding structures, then they provide galvanic isolation and voltage transformation, but they suffer from higher losses and are not optimized for high currents
Solution Approach 1:
The transformer is divided into N independent phases, with each phase having its own magnetic path through the soft-magnetic core structure. This segmentation allows each phase to handle current independently, optimizing the overall current handling capability while reducing losses through distributed magnetic paths
Solution Approach 2:
The patent applies different winding configurations to different parts of the transformer: primary windings are wound around the core structure while secondary windings pass through openings without being wound around the core. This local differentiation optimizes each winding type for its specific function, reducing overall losses
2Volume of moving object
If the size of transformers is reduced by miniaturizing magnetic cores, then compactness is achieved, but current handling capability and power output are limited
Solution Approach 1:
The patent transitions from conventional planar core designs to a three-dimensional soft-magnetic core structure with N openings passing through it. This dimensional change allows multiple magnetic paths to coexist in a compact volume, enabling high power output while maintaining small transformer size
Solution Approach 2:
The N secondary windings are positioned to pass through the N openings of the core structure, effectively nesting the windings within the core's three-dimensional structure. This nesting allows multiple windings to occupy minimal space while maintaining electrical isolation and magnetic coupling
3Reliability
If secondary windings are wound around the core structure to provide galvanic isolation, then isolation is achieved, but winding length increases leading to higher Joule heating
Solution Approach 1:
The secondary windings are extracted from the conventional wound-around configuration and repositioned to pass directly through the core openings. This extraction eliminates the need for lengthy winding paths while maintaining galvanic isolation through the magnetic coupling provided by the soft-magnetic core structure
Solution Approach 2:
The patent replaces the mechanical winding structure with a magnetic coupling mechanism. Instead of physically winding secondary conductors around the core, the design uses magnetic fields through the soft-magnetic core to transfer energy, significantly reducing conductor length and Joule heating while maintaining isolation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The assembly allows for compact, high-current transformers with reduced losses, suitable for high-power applications such as charging batteries in electric vehicles and powering data center servers.
Implementation Method 1
a closed-loop magnetic path around each of the N openings
Implementation Method 2
the soft-magnetic core structure is designed to provide a magnetizing inductance for the resonant tank
Implementation Method 3
at least one air gap is present within the soft-magnetic core structure
Implementation Method 4
the corresponding primary winding is distanced from the corresponding secondary winding to provide through leakage a resonant inductance
Implementation Method 5
Each primary winding of the N primary windings is wound in such a way around the soft-magnetic core structure that it passes through the corresponding opening
Implementation Method 6
each secondary winding of the N secondary windings passes through the corresponding opening
Implementation Method 7
using soft-magnetic materials like ferrites to enhance leakage inductance
Implementation Method 8
the corresponding primary winding is distanced from the corresponding secondary winding to provide through leakage a resonant inductance for a resonant tank
Data Source
AI summary
The disclosure relates to an N-phase transformer assembly with N phases for an N-phase LLC resonant converter, with N being a natural number greater than or equal to one. The N-phase transformer assembly comprises (i) a soft-magnetic core structure, which comprises N openings passing through the soft-magnetic core structure and a closed-loop magnetic path around each of the N openings, wherein at least one air gap is present within the soft-magnetic core structure, and (ii) N primary windings and N secondary windings. wherein each primary winding of the N primary windings is wound in such a way around the soft-magnetic core structure that it passes through the corresponding opening, wherein the N secondary windings are not wound around the soft-magnetic core structure and each secondary winding of the N secondary windings passes through the corresponding opening.