Modular DC-DC Converter Stages for High-Ratio Low-Stress Conversion

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Solution Overview

Problem

Conventional DC-DC converters face inefficiencies due to systemic energy loss and increased complexity as the transformation ratio increases, requiring a large number of capacitors and switches, which can lead to high switch stress and output resistance.

Innovation Solution

The modular architecture of DC-DC converters allows for the mixing and matching of switching networks and regulating circuits, utilizing adiabatic charging and diabatic discharging principles to minimize energy loss, with specific topologies like series-parallel and cascade multipliers, and incorporating magnetic storage elements to control RMS currents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the transformation ratio increases in conventional DC-DC converters, then the voltage conversion capability improves, but the number of capacitors and switches increases leading to higher device complexity

Engineering Contradiction:
Improvevoltage conversion capabilityVSAvoidnumber of capacitors and switches
Core Design Contradiction:
PowerVSDevice complexity

Solution Approach 1:

The converter is divided into multiple modular stages, each with a switching network and regulating circuit. This segmentation allows the overall transformation ratio to be achieved through cascaded stages rather than requiring a single complex stage, thereby reducing the number of components needed in each individual stage while maintaining the total voltage conversion capability.

Inventive Principle:
Principle #1Segmentation

2Power

If the transformation ratio increases in conventional DC-DC converters, then the voltage conversion capability improves, but the switch stress increases

Engineering Contradiction:
Improvevoltage conversion capabilityVSAvoidswitch stress
Core Design Contradiction:
PowerVSStress or pressure

Solution Approach 1:

By dividing the voltage conversion into multiple stages, the voltage stress on individual switches is reduced. Each switching network operates at a lower voltage level compared to a single-stage converter achieving the same total transformation ratio, thereby reducing switch stress and improving reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The regulating circuits dynamically adjust the operation of switching networks to optimize switch stress distribution. The modular architecture allows flexible configuration where switches operate under more favorable electrical conditions, reducing peak stress levels.

Inventive Principle:
Principle #15Dynamics

3Power

If the transformation ratio increases in conventional DC-DC converters, then the voltage conversion capability improves, but the output resistance increases

Engineering Contradiction:
Improvevoltage conversion capabilityVSAvoidoutput resistance
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The multi-stage modular architecture reduces output resistance by distributing the voltage transformation across multiple stages. Each stage contributes to the overall conversion while maintaining lower impedance levels, resulting in reduced total output resistance compared to a single-stage converter with the same transformation ratio.

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 approach reduces systemic energy loss, allows for flexible configuration, and achieves lower output resistance and switch stress, enabling efficient power conversion with smaller capacitors and reduced switching frequency, while maintaining high efficiency.

Implementation Method 1

utilizing adiabatic charging and diabatic discharging principles to minimize energy loss

Methodology Applied
Scientific EffectAdiabatic charging: Adiabatic Heating

Implementation Method 2

a first capacitor of the first group is charged by a second capacitor of the second group

Methodology Applied
Scientific EffectCapacitance: Capacitance

Implementation Method 3

incorporating magnetic storage elements to control RMS currents

Methodology Applied
Scientific EffectMagnetic energy storage: Inductor

Data Source

PatentEP3425784B1DC-DC converter with modular stages
Publication Date: 2023.09.06 PSEMI CORP
  • EP3425784B1 patent drawingFigure 1~2
  • EP3425784B1 patent drawingFigure 3~4
  • EP3425784B1 patent drawingFigure 5~6

AI summary

An apparatus for electric power conversion comprises an AC switching network connected to a regulating circuit comprising an inductor. The regulating circuit maintains an average DC current through the inductance. The AC switching network comprises switches that, when connected to charge-storage elements, define a switched-capacitor network, wherein the switches are controllable to switch between switching configurations such that, when the switching network is connected to charge-storage elements, each switching configuration defines a different arrangement of charge-storage elements in the switched-capacitor network. The switched-capacitor network transitions between first and second arrangements of the charge-storage elements so as to cause a transformation between an AC voltage on a first port of the switching network and a voltage with a non-zero average voltage on a second port of the switching network.