Vehicle Battery System Module Balancing via Relay Control

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Solution Overview

Problem

Conventional high voltage-low voltage integrated battery systems for vehicles face inefficiencies due to imbalances in the states of charge between battery modules, leading to unstable operation and reduced robustness.

Innovation Solution

A battery system that employs a battery manager to control relays and a converter to balance energy storage amounts between multiple battery modules, allowing parts of the high voltage battery assembly to be used for low voltage systems, thereby eliminating the need for separate low voltage batteries and enhancing overall system efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single battery assembly is used to integrate both high voltage and low voltage functions, then the number of separate battery systems is reduced and space is saved, but imbalances in state of charge between modules occur leading to unstable operation

Engineering Contradiction:
Improvenumber of separate battery systemsVSAvoidoperational stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The battery assembly is divided into multiple battery modules (first battery module and second battery module), each capable of independent state management. This segmentation allows the system to handle charge imbalances at the module level while maintaining overall integration, resolving the contradiction between system consolidation and operational stability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system dynamically switches between different operational modes (first mode and second mode) based on the state of charge balance between modules. The battery manager continuously monitors and adjusts the operational mode to maintain stability, transforming a static integrated system into a dynamic one that can adapt to changing conditions.

Inventive Principle:
Principle #15Dynamics

2Ease of manufacture

If parts of battery modules are used for both high voltage and low voltage supply, then manufacturing costs and space are reduced, but system robustness decreases due to charge imbalance

Engineering Contradiction:
Improvemanufacturing cost and spaceVSAvoidsystem robustness
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The battery modules are designed to serve multiple functions - they can operate as high voltage sources, low voltage sources, or be charged from other modules depending on the operational mode. This multi-functionality allows a single battery assembly to replace what would traditionally require separate high voltage and low voltage battery systems, achieving cost and space savings while maintaining robustness through proper mode management.

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

Solution Approach 2:

The system changes operational parameters (voltage levels, current flow directions, connection configurations) based on the detected state of charge balance. By dynamically adjusting these parameters, the system can optimize performance and maintain robustness while utilizing the same physical battery modules for multiple functions.

Inventive Principle:
Principle #35Parameter changes

3Reliability

If energy is transferred between battery modules to balance charge, then operational stability is improved, but energy loss occurs during the transfer process

Engineering Contradiction:
Improveoperational stabilityVSAvoidenergy loss during transfer
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The battery modules perform self-balancing by transferring energy between themselves when charge imbalances are detected. The system uses the existing energy within the battery assembly to recharge imbalanced modules rather than requiring external power sources, minimizing energy loss while maintaining operational stability.

Inventive Principle:
Principle #25Self-service

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 stabilizes the operation of the battery system, reduces the need for additional space and manufacturing costs, and increases the total capacity for high voltage power, enhancing mileage and engine power by effectively managing energy distribution between modules.

Implementation Method 1

a converter converting a voltage of energy of the battery assembly being applied to the input/output end and selectively providing the converted voltage to the first battery module

Methodology Applied
Scientific EffectVoltage conversion:

Data Source

PatentEP3473487B1Battery system for vehicle
Publication Date: 2023.05.03 HYUNDAI MOTOR CO LTD
  • EP3473487B1 patent drawingFigure 1
  • EP3473487B1 patent drawingFigure 2
  • EP3473487B1 patent drawingFigure 3

AI summary

A battery system for a vehicle includes: a battery assembly including at least one first battery module and at least one second battery module; a first relay being closed/opened between a first node and one of a first end of the first battery module and a first end of the second battery module being connected to a second end of the first battery module; a second relay being closed/opened between a second node and a second end of the second battery module; a converter converting a voltage between the nodes; a third relay being closed/opened between the converter and the first end of the first battery module; a fourth relay being closed/opened between the first end of the first battery module and a ground; and a battery manager controlling the relays based on a driving condition of the vehicle and energy storage amounts of the modules.