Integrated EV Conversion Device with Galvanic Isolation

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Solution Overview

Problem

Existing electric vehicle conversion devices are bulky, costly, and sensitive to electrical network harmonics, lacking galvanic isolation and requiring complex mechanical actuation for mode switching, which complicates operations and increases manufacturing costs.

Innovation Solution

A conversion device integrating a single circuit for multiple functions, including a transformer for galvanic isolation and an active filter to mitigate harmonics, allowing seamless mode switching without mechanical actuation, thus reducing bulk, cost, and sensitivity to network harmonics.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate power electronic devices (inverter, charger, DC-DC converter) are used, then each device can be optimized for its specific function, but the overall device bulk increases and manufacturing cost rises

Engineering Contradiction:
Improvefunctional optimizationVSAvoiddevice bulk
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent combines the inverter, charger, and DC-DC converter functions into a single integrated power electronic device. This merging approach reduces the overall device bulk and manufacturing cost while maintaining the functional capabilities of each individual component through shared power semiconductor bridges and control systems.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The integrated device performs multiple functions simultaneously - it can operate as an inverter, charger, or DC-DC converter depending on the operational mode. The same power electronic components serve multiple purposes, eliminating the need for separate dedicated devices for each function.

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

2Ease of operation

If separate power electronic devices are used, then each device can be independently controlled, but the thermal constraints require complex cooling systems increasing device bulk

Engineering Contradiction:
Improveindependent controlVSAvoidcooling system bulk
Core Design Contradiction:
Ease of operationVSVolume of stationary object

Solution Approach 1:

The patent implements a unified cooling system that serves all power electronic components simultaneously. The cooling apparatus is designed to handle the thermal loads from multiple functions (inversion, charging, DC-DC conversion) through a single integrated thermal management pathway, reducing the overall cooling system bulk.

Inventive Principle:
Principle #5Merging (Combining)

3Reliability

If mechanical actuation is used for mode switching, then clear physical separation between modes is achieved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improvemode separationVSAvoidmechanical actuation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent replaces mechanical actuation mechanisms with electronic control for mode switching. Solid-state switching devices and control circuits are used to transition between operational modes (inverter, charger, DC-DC converter) without any moving parts, thereby reducing device complexity and eliminating mechanical wear while maintaining clear functional separation through control logic.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

4Reliability

If galvanic isolation elements are added to meet safety standards, then electrical safety is improved, but the device bulk and manufacturing cost increase

Engineering Contradiction:
Improveelectrical safetyVSAvoiddevice bulk
Core Design Contradiction:
ReliabilityVSVolume of stationary object

Solution Approach 1:

The patent integrates galvanic isolation functionality into the existing power electronic structure rather than adding separate isolation components. The isolation is achieved through the inherent properties of the power semiconductor devices and their control architecture, maintaining safety standards while minimizing additional bulk.

Inventive Principle:
Principle #5Merging (Combining)

5Productivity

If the conversion device is connected directly to the electrical network, then energy transfer efficiency is improved, but the device becomes sensitive to network harmonics causing component degradation

Engineering Contradiction:
Improveenergy transfer efficiencyVSAvoidharmonic sensitivity
Core Design Contradiction:
ProductivityVSObject-affected harmful factors

Solution Approach 1:

The patent employs an active filter function within the integrated device to detect and counteract network harmonics. The same power electronic components that enable efficient energy transfer are also used to generate compensating currents that cancel out harmful harmonics, converting the potential harm into a beneficial filtering effect.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The device incorporates feedback control mechanisms that continuously monitor the electrical network conditions and adjust the power electronic switching patterns to mitigate harmonic effects. This feedback loop allows the system to maintain efficient energy transfer while actively compensating for network disturbances in real-time.

Inventive Principle:
Principle #23Feedback

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

The integrated solution results in a more compact, cost-effective, and safer conversion device with reduced harmonic impact, suitable for high-power vehicles, enabling efficient energy transfer and reduced component degradation.

Implementation Method 1

a transformer configured to transfer, by electromagnetic induction, electrical energy between a direct current network and an alternating current network

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an active filter configured to mitigate harmonics transported by the electrical network

Methodology Applied
Scientific EffectActive filtering: Filter (electronic)

Data Source

PatentEP3389175B1Conversion device, associated control method and vehicle
Publication Date: 2021.12.15 IFP ENERGIES NOUVELLES
  • EP3389175B1 patent drawingFigure 1
  • EP3389175B1 patent drawingFigure 2

AI summary

The invention relates to a conversion device (4) for transferring electrical energy between a direct current network (6) and an alternating current network (10), the conversion device (4) comprising: - a DC-DC converter (12) comprising a low voltage branch (16) and a high voltage branch (18) each comprising two sub-branches (34) in series, each sub-branch (34) comprising a switching module (38); - a reversible DC-AC converter (14); - a controller (15) configured to control the on or off state of each switching module (38), the controller (15) being further configured to control the reversible DC-AC converter (14) to transfer electrical energy from the DC-DC converter (12) to the alternating current network (10), or from the alternating current network (10) to the DC-DC converter (12).