Powder Core Coupled Inductor with Embedded Windings

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Solution Overview

Problem

Conventional coupled inductors in multi-phase DC-DC converters face challenges in achieving optimal leakage inductance and magnetic coupling, leading to inefficiencies in ripple current management and transient response.

Innovation Solution

The development of coupled inductors with multiple windings embedded in a monolithic magnetic core formed from powdered magnetic material, where windings are physically separated to create leakage inductance and magnetically coupled for efficient magnetic flux transfer, allowing for adjustable leakage and magnetizing inductance through core composition and winding alignment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If windings are physically separated within the magnetic core, then leakage inductance is increased and ripple current management is improved, but magnetic coupling between windings is reduced

Engineering Contradiction:
Improveripple current management efficiencyVSAvoidmagnetic coupling between windings
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies local quality by creating different spatial relationships between windings within the same magnetic core. Specifically, certain windings are positioned in close proximity to each other to achieve strong magnetic coupling for efficient energy transfer, while other windings are deliberately separated to generate appropriate leakage inductance for ripple current management. This localized variation in spatial arrangement allows simultaneous optimization of both magnetic coupling and leakage inductance within the same inductor component.

Inventive Principle:
Principle #3Local quality

2Volume of moving object

If multiple windings are embedded in a monolithic magnetic core, then inductance values are optimized and device size is reduced, but manufacturing complexity increases

Engineering Contradiction:
Improvedevice sizeVSAvoidmanufacturing complexity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The patent applies preliminary action by pre-positioning multiple windings within the magnetic core structure before final assembly. The windings are arranged in specific configurations during the manufacturing process to achieve desired inductance values and coupling characteristics, rather than requiring post-manufacturing adjustments. This pre-arrangement of windings simplifies the overall manufacturing process despite the complexity of embedding multiple windings in a monolithic core.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent employs composite materials by integrating multiple windings made of different conductive materials (such as copper and aluminum) within a single monolithic magnetic core. This composite structure allows optimization of electrical properties for different windings while maintaining a unified magnetic core, thereby reducing overall device size and improving manufacturing efficiency compared to using separate inductor components.

Inventive Principle:
Principle #40Composite materials

3Speed

If leakage inductance is increased through winding separation, then transient response is improved, but magnetic flux transfer efficiency is reduced

Engineering Contradiction:
Improvetransient responseVSAvoidmagnetic flux transfer efficiency
Core Design Contradiction:
SpeedVSLoss of energy

Solution Approach 1:

The patent applies parameter changes by systematically varying the spatial parameters of winding arrangements within the magnetic core. Specifically, the distance between windings, the orientation of windings relative to each other, and the position of windings within the core cross-section are adjusted to achieve optimal leakage inductance values. These parameter variations enable the inductor to provide appropriate transient response characteristics while maintaining sufficient magnetic flux transfer efficiency for the intended application.

Inventive Principle:
Principle #35Parameter changes

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 enhances the efficiency of ripple current management and transient response in DC-DC converters by optimizing leakage inductance and magnetic coupling, reducing core losses and enabling smaller, cost-effective solutions.

Implementation Method 1

The magnetic core provides a path for magnetic flux to magnetically couple the windings

Methodology Applied
Scientific EffectMagnetic coupling: Magnetic Field

Implementation Method 2

The second winding is at least partially physically separated from the first winding within the magnetic core, creating leakage inductance

Methodology Applied
Scientific EffectLeakage inductance: Magnetic Reluctance

Data Source

PatentEP2577856B1Powder core material coupled inductors and associated methods
Publication Date: 2021.08.18 VOLTERRA SEMICONDUCTOR CORPORATION
  • EP2577856B1 patent drawingFigure 1~3
  • EP2577856B1 patent drawingFigure 4~5
  • EP2577856B1 patent drawingFigure 6~8

AI summary

A multi-phase coupled inductor includes a powder core material magnetic core and first, second, third, and fourth terminals. The coupled inductor further includes a first winding at least partially embedded in the core and a second winding at least partially embedded in the core. The first winding is electrically coupled between the first and second terminals, and the second winding electrically is coupled between the third and fourth terminals. The second winding is at least partially physically separated from the first winding within the magnetic core. The multi-phase coupled inductor is, for example, used in a power supply.