Vehicle Propulsion Power Control for Regenerative Braking Overcharge

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Electric and hybrid vehicles face challenges with battery overcharge during regenerative braking, leading to energy loss, increased battery temperature, and reduced durability, as well as excessive wear on mechanical brakes due to incomplete kinetic energy recovery.

Innovation Solution

A vehicle propulsion device incorporating a motor generator, storage battery, and thermoelectric conversion elements, with a power control unit that manages power transfer to charge the battery and cool the motor generator during braking, reducing the risk of overcharge and enhancing energy recovery by converting thermal energy into electric power.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If regenerative braking is used for prolonged time or with frequency on downhill, then kinetic energy recovery is improved, but battery overcharge occurs

Engineering Contradiction:

Improvekinetic energy recoveryVSAvoidbattery overcharge

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent extracts the cooling function from the traditional battery thermal management system and integrates it into the regenerative braking process. The motor generator is used not only for energy recovery but also for cooling the battery through controlled operation, thereby preventing overheating that would limit regenerative braking usage.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The motor generator performs multiple functions simultaneously: it recovers kinetic energy as electrical energy and also serves as a cooling device for the battery. This multi-functionality allows the system to extend regenerative braking usage without causing battery overheating or overcharge.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If battery charging capacity is increased to prevent overcharge, then battery durability is improved, but vehicle weight increases and passenger space reduces

Engineering Contradiction:

Improvebattery durabilityVSAvoidvehicle weight

Core Design Contradiction:

ReliabilityVSWeight of moving object

Solution Approach 1:

The system uses the motor generator itself to provide cooling service to the battery during regenerative braking, rather than requiring a separate cooling system. This self-service approach extends battery life and enables more frequent regenerative braking without adding extra cooling equipment or increasing battery capacity.

Inventive Principle:

Principle #25Self-service

3Reliability

If mechanical brake is used concurrently with regenerative braking, then battery overcharge is prevented, but kinetic energy recovery is reduced

Engineering Contradiction:

Improvebattery overcharge preventionVSAvoidkinetic energy recovery

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The patent replaces the need for mechanical brake intervention with an electrical control solution. The power control unit dynamically adjusts the electrical load on the motor generator during regenerative braking to prevent battery overcharge, eliminating the need to switch to mechanical brakes and thereby maintaining kinetic energy recovery efficiency.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

4Loss of energy

If battery temperature rises due to overcharge, then power loss in battery increases, but no direct control mechanism is provided

Engineering Contradiction:

Improvepower loss in batteryVSAvoidbattery temperature

Core Design Contradiction:

Loss of energyVSTemperature

Solution Approach 1:

The system implements feedback control by monitoring battery temperature and charge state, and dynamically adjusting the motor generator operation accordingly. When the battery approaches overcharge or overheating conditions, the control unit modifies the electrical load to maintain optimal temperature and prevent power loss.

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

This solution decreases the likelihood of battery overcharge, improves battery durability, reduces power loss, and lowers the dependence on mechanical brakes, resulting in enhanced energy-use efficiency and reduced fuel consumption in hybrid vehicles.

Implementation Method 1

a first thermoelectric conversion element that is thermally connected to the motor generator

Methodology Applied

Scientific EffectThermoelectric conversion: Peltier Effect

Implementation Method 2

the regenerated electric power obtained by operating the motor generator as a generator is stored in the battery

Methodology Applied

Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentUS8322474B2Vehicle propulsion device

Publication Date: 2012.12.04 ATSUMITEC CO LTD

AI summary

When a drive wheel (3) of a vehicle is driven by a motor generator (10) that operates as a motor, electric power is supplied from a storage battery (20) to the motor generator (10). When the drive wheel (3) is braked by the motor generator (10) that operates as a generator, electric power is supplied from the motor generator (10) to the storage battery (20), and a first thermoelectric conversion element (11) is supplied with electric power from the motor generator (10) to cool the motor generator (10).