Vehicle Cooling Circuit Control for Braking Energy Dissipation

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Solution Overview

Problem

Vehicles propelled by electric machines face challenges in managing energy dissipation during regenerative braking events and require controllable cooling for their components, especially when the electrical storage system is full, and existing cooling systems do not effectively decouple electric heat sources and heat generating arrangements for optimized temperature control.

Innovation Solution

A cooling system with a radiator, multiple fluid circuits, and a control unit that directs fluid flow based on vehicle operation modes, including a braking mode to dissipate energy through a heat generating arrangement and a start-up mode to heat the electric heat source efficiently, using a compressor arrangement and reversing valve to manage refrigerant flow.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the electrical storage system is used to receive additional electric energy during regenerative braking, then energy management is improved, but the system cannot receive further energy when the State-Of-Charge (SOC) level is above a predetermined threshold limit

Engineering Contradiction:
Improveenergy dissipationVSAvoidenergy reception capability
Core Design Contradiction:
Use of energy by moving objectVSAdaptability or versatility

Solution Approach 1:

The patent introduces a heat generating arrangement as an intermediary component that converts excess electrical energy into thermal energy when the electrical storage system cannot accept additional energy. This mediator enables continuous energy dissipation by transforming the energy that would otherwise be wasted into useful heat for heating the electric heat source or the cabin.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The system changes the energy parameter from electrical to thermal by using the heat generating arrangement. When the SOC threshold is exceeded, the system transitions from storing electrical energy to generating heat, thereby maintaining energy dissipation capability while adapting to the storage system's charge limits.

Inventive Principle:
Principle #35Parameter changes

2Temperature

If a cooling system is designed to cool components during operation, then temperature control is improved, but the system lacks sophisticated energy dissipation management during braking events

Engineering Contradiction:
Improvecomponent temperature controlVSAvoidenergy dissipation management
Core Design Contradiction:
TemperatureVSAdaptability or versatility

Solution Approach 1:

The cooling system is designed with multi-functionality to serve both cooling and heating purposes. The same fluid circuits and heat exchangers used for cooling components during operation are repurposed to dissipate energy and provide heating during braking events, eliminating the need for separate systems and improving overall adaptability.

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

Solution Approach 2:

The system dynamically switches between cooling and heating modes based on operational conditions. During regenerative braking, when energy dissipation is needed, the system transitions from a static cooling function to an active energy management mode that can both cool components and generate heat, adapting to changing operational requirements in real-time.

Inventive Principle:
Principle #15Dynamics

3Temperature

If the cooling system cools the electric heat source during operation, then temperature control is improved, but the system cannot rapidly heat the electric heat source during start-up or braking modes

Engineering Contradiction:
Improveelectric heat source temperature controlVSAvoidheating speed
Core Design Contradiction:
TemperatureVSSpeed

Solution Approach 1:

The system converts the harmful excess energy generated during braking into a beneficial heating source. The heat generating arrangement transforms electrical energy that would be wasted into thermal energy that rapidly heats the electric heat source, turning an energy management problem into a heating solution.

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

Solution Approach 2:

The system prepares for rapid heating by having the heat generating arrangement and associated fluid circuits pre-configured and ready to operate. When heating is required, the system can immediately activate the heat generation and circulate the heated fluid through the electric heat source, achieving rapid temperature increase without delay.

Inventive Principle:
Principle #10Preliminary action

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 system enhances energy dissipation and temperature control by decoupling electric heat sources and heat generating arrangements, allowing for improved thermal management and rapid heating of electric heat sources during different vehicle modes.

Implementation Method 1

a radiator configured to receive ambient air

Methodology Applied
Scientific EffectHeat exchange: Convection

Implementation Method 2

a radiator configured to receive ambient air

Methodology Applied
Scientific EffectThermal radiation: Thermal Radiation

Implementation Method 3

the heat generating arrangement is, during the vehicle braking mode, configured to dissipate electric power to the fluid flow in the first fluid circuit

Methodology Applied
Scientific EffectJoule heating: Joule Heating

Implementation Method 4

a condenser configured to exchange heat with ambient air

Methodology Applied
Scientific EffectHeat exchange: Convection

Implementation Method 5

a heat exchanger, wherein the heat exchanger is fluidly connected to the second circuit valve arrangement and to the second fluid circuit

Methodology Applied
Scientific EffectHeat exchange: Convection

Implementation Method 6

a heat exchanger, wherein the heat exchanger is fluidly connected to the second circuit valve arrangement and to the second fluid circuit

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP4113704B1A cooling system, and a method of controlling a cooling system
Publication Date: 2025.11.19 VOLVO TRUCK CORP
  • EP4113704B1 patent drawingFigure 1
  • EP4113704B1 patent drawingFigure 2~3
  • EP4113704B1 patent drawingFigure 4~5

AI summary

The present invention relates to a cooling system for a vehicle propelled by an electric machine. The cooling system is arranged, when the vehicle is operated in a braking mode, to control a first and a second radiator valve to direct a flow of fluid from a radiator through a first fluid circuit and prevent the flow of fluid from the radiator to enter the second fluid circuit, control a compressor arrangement to flow a refrigerant in a direction from a heat exchanger to a condenser of a third fluid conduit, and control a second circuit valve arrangement to direct a heat source fluid to circulate through a heat exchanger and an electric heat source.