Multi-Phase DC/DC Converter with Buck-Boost and Boost Topologies

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Solution Overview

Problem

Existing DC/DC converter systems for fuel cell vehicles require a large number of semiconductor switches and complex control logic, leading to high installation space, weight, and cost, as well as inefficiency due to the need for multiple operating modes and adaptations to current-voltage characteristics, particularly when the input voltage can be higher or lower than the output voltage.

Innovation Solution

A multi-phase DC/DC converter system with separate switching devices controlling first and second DC voltage converters, where the first converter operates in both step-down and step-up modes, and the second converter is designed for only step-up mode, allowing for decoupling and simplified topology with fewer switching elements, optimizing energy transfer based on the fuel cell's current-voltage characteristic.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple DC/DC converters are connected in parallel with separate switching devices, then voltage conversion efficiency is improved and adaptability to current-voltage characteristics is enhanced, but device complexity and control logic requirements increase

Engineering Contradiction:
Improvevoltage conversion efficiencyVSAvoidcontrol logic complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system divides the DC/DC conversion function into multiple parallel converters (first and second converters), each handling different voltage ranges. This segmentation allows each converter to be optimized for specific operating conditions, improving overall efficiency while distributing control complexity across modular units

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first DC/DC converter is designed with multi-functionality to operate in both step-down mode (when input voltage exceeds output voltage) and step-up mode (when input voltage is below output voltage). This universal design reduces the need for separate dedicated converters for each mode, thereby simplifying control logic while maintaining high productivity

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

2Ease of manufacture

If the second DC/DC converter is designed exclusively for step-up mode, then manufacturing precision and ease of manufacture are improved, but adaptability to varying voltage conditions is reduced

Engineering Contradiction:
Improveconverter design simplicityVSAvoidvoltage range adaptability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The system segments the voltage conversion task by assigning the second DC/DC converter to handle only step-up operations, while the first converter manages step-down and bidirectional operations. This segmentation simplifies the second converter's design and manufacturing while the first converter compensates for the reduced adaptability of the second

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The first and second DC/DC converters are merged into a parallel configuration where their combined capabilities cover the full range of voltage conversion needs. The second converter's simplified step-up design complements the first converter's bidirectional design, achieving overall system versatility without requiring each individual converter to handle all modes

Inventive Principle:
Principle #5Merging (Combining)

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 configuration reduces semiconductor components and control logic complexity, lowering installation space, weight, and costs while improving efficiency by selectively engaging the second converter to manage voltage conversion efficiently across varying input and output voltages.

Implementation Method 1

each having at least one switching element (11; 21, 21'; 12; 22, 22') and at least one inductor (15; 25, 25')

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3024130B1DC/DC converter
Publication Date: 2017.08.02 BRUSA ELEKTRONIK AG
  • EP3024130B1 patent drawingFigure 1
  • EP3024130B1 patent drawingFigure 2~3
  • EP3024130B1 patent drawingFigure 4~5

AI summary

The invention relates to a multi-phase DC/DC converter device (10) with a DC voltage input (3), a DC voltage output (4) and parallel-connected DC voltage converters (1, 2, 2'), each of which has at least one switching element (11, 12, 13, 14) controlled by a control device (16);21, 22, 21', 22'), characterized in that of the parallel-connected DC/DC converters (1, 2, 2') at least one first DC/DC converter (1) is configured as a buck and boost converter in the direction from the DC input (3) to the DC output (4) and at least one second DC/DC converter (2, 2') is configured as a boost converter in the direction from the DC input (3) to the DC output (4), wherein the topology of the at least one first DC/DC converter (1) differs from the topology of the at least one second DC/DC converter (2, 2'), and that the DC/DC converter device (10) comprises at least one switching device (5).