Dual-Battery Circuit Assembly for Fault-Tolerant Control Power

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Solution Overview

Problem

Current safety concepts for batteries, such as lithium-ion batteries, fail to ensure continuous operation when faults occur, particularly in the event of voltage detection errors, leading to separation from the vehicle's on-board power system, and there is a need to maintain availability of the 48V battery system even if the 12V battery fails.

Innovation Solution

An electrical circuit arrangement with a circuit board having separated high-resistance areas, utilizing a first 12V battery for power supply to one area and a second 48V battery through a filter circuit, DC-DC converter, and semiconductor switch to maintain control unit operation independently of the first energy storage, allowing seamless switching in case of a fault.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single power supply system is used for control units in battery management, then the device complexity is reduced, but the reliability deteriorates because a fault in one battery can cause system-wide failure

Engineering Contradiction:
Improvesystem availabilityVSAvoidpower supply structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control unit is divided into two independently powered areas: a first area powered by the first battery and a second area powered by the second battery through a DC-DC converter. This segmentation allows each area to operate independently, ensuring that a fault in one battery does not affect the other, thereby resolving the contradiction between reliability and complexity by distributing power supply responsibilities.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A DC-DC converter is introduced as an intermediary component between the second battery and the second area of the control unit. This mediator enables independent power supply from the second battery to specific control functions, allowing the system to maintain critical operations even when one battery fails, thus improving reliability without requiring a completely complex dual-power-architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Reliability

If safety measures disconnect the battery in fault conditions, then safety is improved, but the productivity deteriorates due to system unavailability

Engineering Contradiction:
ImprovesafetyVSAvoidsystem availability
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The control unit is segmented into two independently powered areas, where the first area handles basic control functions powered by the first battery, and the second area handles additional functions powered by the second battery. In fault conditions, the system can maintain critical functions through the first area while isolating faults in the second area, thereby preserving safety while maintaining system availability and productivity.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system is designed with redundant power supply paths established beforehand, where the first battery can sustain critical control functions even when the second battery fails. This prior cushioning ensures that safety measures can be implemented without completely shutting down the system, thus maintaining productivity while ensuring safety.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

3Reliability

If the same safety objective is applied to both 12V and 48V batteries, then safety consistency is improved, but the device complexity increases due to additional safety components

Engineering Contradiction:
Improvesafety consistencyVSAvoidsafety components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The control unit is segmented into two independently powered areas, each with its own power supply path. This segmentation inherently provides safety consistency for both 12V and 48V batteries without requiring additional safety components, as each battery independently powers its designated area. The first battery powers the first area and the second battery powers the second area through the DC-DC converter, eliminating the need for complex cross-protection mechanisms.

Inventive Principle:
Principle #1Segmentation

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

Ensures continuous operation of the control unit even if the first energy storage device fails, maintaining system availability and preventing 48V battery failure due to 12V battery faults, thereby enhancing safety and reliability in energy storage systems for vehicles and other applications.

Implementation Method 1

an electrical connection between the second connection and the control unit comprises a filter circuit

Methodology Applied
Scientific EffectFiltering: Filter (electronic)

Implementation Method 2

a DC-DC converter and a switching element, wherein the filter circuit can be electrically connected to the DC-DC converter

Methodology Applied
Scientific EffectElectrical voltage conversion: Electromagnetic Induction

Data Source

PatentEP3798039B1Electrical circuit assembly for an energy storage system and method for operating the electrical circuit assembly
Publication Date: 2023.12.27 ROBERT BOSCH GMBH
  • EP3798039B1 patent drawingFigure 1

AI summary

Electrical circuit arrangement for an energy storage system with a first electrochemical energy storage device and a second electrochemical energy storage device.