Matrix Transformer Current Doubler Layout for Low-Leakage DC-DC Conversion

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Solution Overview

Problem

Current DC-DC converters with current doubler rectifiers face challenges such as high cost due to the use of multiple magnetic components, leading to increased termination power loss and reduced power density, especially when operating with a 48V bus voltage for data centers and telecom applications.

Innovation Solution

The integration of a matrix transformer with multiphase current doubler rectifiers, utilizing a split primary winding and interleaving technique to minimize leakage inductance and reduce core losses, along with negative coupling between inductors to enhance efficiency and power density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If multiple magnetic components (transformer and inductors) are used in current doubler rectifier topology, then the converter can achieve high current output capability, but the system cost increases and power density decreases

Engineering Contradiction:

Improvecurrent output capabilityVSAvoidnumber of magnetic components

Core Design Contradiction:

PowerVSDevice complexity

Solution Approach 1:

The patent combines the transformer and two inductors into a single integrated magnetics component with one core containing three windings. The primary winding and two secondary windings are wound on the same core, eliminating the need for separate magnetic components and reducing overall system complexity while maintaining the current doubler rectifier's high current capability

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The integrated magnetics component serves multiple functions simultaneously: it acts as the transformer for voltage conversion and as both inductors required for the current doubler rectifier operation. This multi-functional design reduces component count while preserving all necessary circuit functions

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Device complexity

If traditional integrated magnetics topology with primary winding in center leg and secondary windings in outer legs is used, then component integration is achieved, but large leakage inductance problem occurs

Engineering Contradiction:

Improvecomponent integrationVSAvoidleakage inductance

Core Design Contradiction:

Device complexityVSLoss of energy

Solution Approach 1:

The patent employs asymmetric winding arrangements where the primary winding is divided into two sections wound on opposite outer legs, while the secondary windings are positioned to achieve optimal coupling. This asymmetric configuration minimizes leakage inductance compared to traditional symmetric center-leg topologies

Inventive Principle:

Principle #4Asymmetry

3Device complexity

If one current doubler rectifier is connected to one primary side circuit, then the circuit design is simplified, but power density is limited

Engineering Contradiction:

Improvecircuit design simplicityVSAvoidpower density

Core Design Contradiction:

Device complexityVSPower

Solution Approach 1:

The patent segments the primary winding into two independent primary windings, each capable of driving a separate current doubler rectifier. This segmentation allows two primary-side circuits to be connected to the integrated magnetics, effectively doubling the power density while maintaining manageable circuit design through modular architecture

Inventive Principle:

Principle #1Segmentation

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 solution reduces leakage inductance, improves efficiency, and increases power density by integrating multiple transformer components into a single matrix transformer core, effectively addressing the high cost and power loss issues in existing technologies.

Implementation Method 1

The integration of a matrix transformer with multiphase current doubler rectifiers

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

utilizing a split primary winding and interleaving technique to minimize leakage inductance

Methodology Applied

Scientific EffectLeakage inductance reduction through interleaved winding:

Implementation Method 3

negative coupling between inductors to enhance efficiency and power density

Methodology Applied

Scientific EffectNegative coupling:

Data Source

PatentUS11894778B2High current DC-DC converter with integrated matrix transformer and multiphase current doubler rectifier

Publication Date: 2024.02.06 VIRGINIA TECH INTELLECTUAL PROPERTIES INC

AI summary

Aspects of direct current (DC)-DC converters with an integrated matrix transformer and multiphase current doubler rectifiers are described. In some examples, a DC-DC converter can include a matrix transformer that has multiple magnetically integrated transformer components that are magnetically integrated using transformer components that share a top plate and a bottom plate. A multiphase current doubler rectifier can include multiple synchronous rectifiers corresponding to the plurality of transformer components of the matrix transformer.