Integrated Magnetic Core With Edgewise Windings for Low-Loss Converters

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Solution Overview

Problem

Existing integrated magnetic components for switched mode power converters face challenges in reducing losses, increasing power density, and lowering production costs, particularly in current-doubler rectifiers, due to limitations in winding design and core structures.

Innovation Solution

The use of edgewise wound windings with rectangular cross sections and high permeability magnetic core elements, such as leg-core-elements, allows for higher current capacity, reduced stray inductance, and improved fill factor, enabling compact and efficient designs with automated production.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional round wire or litz wire windings are used for high current secondary windings, then the winding structure is simple to manufacture, but the current capacity is insufficient and copper losses are high

Engineering Contradiction:
Improvecurrent capacityVSAvoidcopper losses
Core Design Contradiction:
Quantity of substanceVSLoss of energy

Solution Approach 1:

The patent changes the fundamental parameter of conductor geometry from round/litz wire to rectangular cross-section conductors. This parameter change enables higher current density and better filling of the winding window, directly increasing current capacity while reducing copper losses through improved current distribution and reduced AC resistance

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent transitions from winding around the longer edge to winding around the shorter edge of rectangular conductors (edgewise winding). This dimensional change in winding orientation maximizes the use of conductor cross-section area, increases effective current carrying capacity, and reduces winding losses by optimizing the current path geometry

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Ease of manufacture

If standardized U/UR cores with bobbinless design are used, then manufacturing costs are reduced and production efficiency increases, but flexibility in mounting and adjusting magnetizing inductance is limited

Engineering Contradiction:
Improvemanufacturing costVSAvoidmounting flexibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent segments the magnetic core into separate modular components that can be assembled in different configurations. This segmentation allows the same core components to be used in various mounting arrangements and enables adjustment of magnetizing inductance by changing the air gap or core assembly, while maintaining the cost benefits of standardized core manufacturing

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces adjustable parameters such as variable air gaps and reconfigurable core assemblies that allow the magnetic component to be dynamically adjusted for different inductance values and mounting requirements. This dynamic flexibility is achieved while using standardized core components that maintain manufacturing efficiency

Inventive Principle:
Principle #15Dynamics

3Reliability

If four windings with additional filter winding are integrated, then effective inductance increases and current ripple is reduced, but device complexity and production costs increase

Engineering Contradiction:
Improvecurrent ripple reductionVSAvoidnumber of windings
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the filter winding function with the transformer windings by using the same rectangular conductors for both transformation and filtering functions. The edgewise wound windings provide both the transformer action and the filtering effect through their inherent inductance, reducing the need for separate dedicated filter windings and simplifying the overall structure

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent designs the windings to serve multiple functions simultaneously - the same windings provide both voltage transformation and current filtering. The rectangular conductor geometry and edgewise winding configuration contribute to both the transformer inductance and the filter inductance, making the winding structure multi-functional and reducing overall device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

4Loss of energy

If tight core-winding coupling is achieved, then leakage inductance is minimized and efficiency increases, but manufacturing precision requirements increase

Engineering Contradiction:
Improveleakage lossesVSAvoidwinding placement precision
Core Design Contradiction:
Loss of energyVSManufacturing precision

Solution Approach 1:

The patent applies local quality optimization by using rectangular conductors with specific aspect ratios and winding them in a specific orientation (edgewise) to naturally achieve tight coupling. The local geometry of the rectangular conductor and its winding orientation create inherent coupling characteristics that minimize leakage inductance without requiring extreme manufacturing precision across the entire component

Inventive Principle:
Principle #3Local quality

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

This design achieves reduced copper losses, lower electromagnetic interference, and lower production costs while enhancing power density and efficiency in DC-DC, AC-DC, and AC-AC power converters, particularly in current-doubler rectifiers.

Implementation Method 1

Transformers and inductors can be integrated into a single magnetic structure

Methodology Applied
Scientific EffectElectromagnetic Induction: Electromagnetic Induction

Implementation Method 2

The tight coupling of primary and secondary windings yields minimized leakage inductance

Methodology Applied
Scientific EffectMagnetic Field: Magnetic Field

Implementation Method 3

high permeability magnetic core elements, such as leg-core-elements

Methodology Applied
Scientific EffectFerromagnetism: Ferromagnetism

Implementation Method 4

Due to introduction of an air gap, the secondary windings not just transform but also store energy

Methodology Applied
Scientific EffectMagnetic Reluctance: Magnetic Reluctance

Data Source

PatentEP3699936B1Integrated magnetic component and switched mode power converter
Publication Date: 2025.10.29 DELTA ELECTRONICS (THAILAND) PUBLIC CO LTD
  • EP3699936B1 patent drawingFigure 1~2
  • EP3699936B1 patent drawingFigure 3~4
  • EP3699936B1 patent drawingFigure 5

AI summary

The invention related to an integrated magnetic component (801) for a switched mode power converter. The integrated magnetic component comprises a single magnetic core structure formed by magnetic core elements (811, 812, 813, 814), wherein at least one of the magnetic core elements (811, 812, 813, 814) is a leg-core-element with a flange (822.4) and one or more legs (820a.4, 820b.4, 821.4) are arranged on one side of the flange (822.4). The magnetic core elements (811, 812, 813, 814) of the single magnetic core structure are linearly stacked. The integrated magnetic component further comprises an isolating transformer with a higher current transformer winding (807.1, 807.2) arranged on at least one leg (821.2, 821.3) of the magnetic core elements (811, 812, 813, 814), a lower current transformer winding (806.1, 806.2) arranged on at least one leg (821.2, 821.3) of the magnetic core elements (811, 812, 813, 814) and a first filter inductor comprising a first filter winding (808.1), arranged on at least one leg (821.1) of the magnetic core elements (811, 812, 813, 814). Herein the higher current transformer winding (807.1, 807.2) and the filter winding comprise (808.1, 808.2) at least an edgewise wound winding part. The invention further relates to a switched mode power converter.