Vehicle Power Converter Cooling With Compensated Dual Propulsion

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Solution Overview

Problem

The existing cooling systems in motor vehicles are insufficient to maintain the performance of power converters, leading to reduced electrical energy supply to safety devices, which can increase the risk of accidents or bodily harm during an accident.

Innovation Solution

A method of controlling the temperature of a power converter by comparing its current temperature with a threshold value and compensating for increased temperature by forcing a second motor to couple with the wheels, reducing the electric motor's workload and focusing the cooling system's efforts on the converter to prevent performance degradation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the cooling system cools both the first inverter and the converter simultaneously, then both components are cooled, but the converter temperature exceeds the threshold value and performance is impaired

Engineering Contradiction:
Improveconverter temperatureVSAvoidelectrical power supply to safety devices
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent segments the cooling strategy by identifying and prioritizing the converter as the critical component requiring cooling. When the converter temperature exceeds the threshold, the system selectively directs cooling resources to the converter, separating it from the first inverter in terms of cooling priority. This segmentation allows the converter to maintain acceptable operating temperature and reliability while the first inverter may operate at higher temperatures.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by providing differential cooling treatment to different components based on their criticality. The converter receives enhanced cooling attention when its temperature exceeds the threshold, while the first inverter receives reduced cooling. This localized quality adjustment ensures that the most critical component (converter) maintains the temperature quality needed for reliable electrical power supply to safety devices.

Inventive Principle:
Principle #3Local quality

2Temperature

If the load on the electric machine is reduced to cool the converter, then the converter temperature decreases, but the motor vehicle loses propulsion capability

Engineering Contradiction:
Improveconverter temperatureVSAvoidpropulsion power
Core Design Contradiction:
TemperatureVSPower

Solution Approach 1:

The patent changes the operational parameters of the motor vehicle by switching between different motor configurations. When converter cooling is required, the system changes from single-electric-machine propulsion to a configuration where a second electric machine compensates for the reduced propulsion capability. This parameter change allows the converter temperature to decrease while maintaining overall propulsion power through the combined operation of multiple machines.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements multi-functionality by introducing a second electric machine that can serve dual purposes: compensating for lost propulsion power and potentially assisting in cooling the converter. This second machine provides universal functionality, stepping in to maintain propulsion capability while the first electric machine's load is reduced to prioritize converter cooling. The system thus maintains both propulsion and cooling functions simultaneously.

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

3Device complexity

If a single cooling system cools multiple components, then the system is compact and simple, but it cannot provide sufficient cooling to the converter when temperature exceeds threshold

Engineering Contradiction:
Improvecooling system structureVSAvoidconverter temperature
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent introduces dynamics into the cooling system by making it adaptable and responsive to real-time temperature conditions. Rather than a static cooling configuration, the system dynamically adjusts its cooling capacity allocation based on converter temperature. When the converter temperature exceeds the threshold, the cooling system dynamically prioritizes the converter, potentially by adjusting coolant flow distribution, pump speeds, or thermal management strategies. This dynamic behavior allows a relatively simple cooling system structure to effectively manage converter temperature without requiring a completely separate dedicated cooling system.

Inventive Principle:
Principle #15Dynamics

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 method ensures effective cooling of the converter, maintaining the electrical energy supply to safety devices and reducing the risk of accidents by ensuring the converter operates within acceptable temperatures.

Implementation Method 1

a cooling system for a plurality of elements including the converter and the first inverter

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP3797045B1Method for controlling a temperature of a converter in a motor vehicle
Publication Date: 2024.02.21 STELLANTIS AUTO SAS
  • EP3797045B1 patent drawingFigure 1~2
  • EP3797045B1 patent drawingFigure 3~4

AI summary

A method for controlling a temperature of a power converter (300) of a motor vehicle (1), the converter connecting an electrical network (410) and a first inverter (112) of an electric propulsion system (110) of the vehicle, the electric propulsion system being coupled by a first coupling device (120) to a wheel (210, 220) of the vehicle so as to propel the latter, the vehicle comprising a system (500) for cooling the components comprising the converter and the first inverter, the control process comprising a comparison between a current temperature value of one of these components cooled by the cooling system and a threshold value and, when the current value is higher than the threshold value, a reduction in the work of the electric propulsion system that propels the vehicle, reduction which is compensated by the work of a second propulsion system (130) that propels the vehicle, by the forced coupling of a second coupling device (140) of the second propulsion system to a wheel.