Irreversible Pyrotechnic Disconnecting Element for High-Voltage Battery Safety

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Electromechanical contactors in high-voltage battery systems for electric and hybrid vehicles are prone to aging and generate excessive heat, compromising safety and reliability, especially in crash situations where safe disconnection from the high-voltage network is critical.

Innovation Solution

A battery system utilizing an irreversible disconnecting element, such as a pyrotechnic switch, with a control unit monitoring two conductor loops to ensure safe disconnection only in emergency situations, avoiding activation during low-voltage network failures and reducing the risk of aging and heat generation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electromechanical contactors are used for disconnecting the high-voltage battery, then the battery can be isolated from the high-voltage network, but the contactors are prone to aging and generate excessive heat, compromising safety and reliability

Engineering Contradiction:

Improvesafety and reliability of disconnectionVSAvoidheat generation and aging

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent replaces electromechanical contactors with a pyrotechnic disconnecting element that uses chemical energy (pyrotechnic reaction) instead of mechanical/electromechanical actuation. This substitution eliminates the aging and heat generation problems associated with electromechanical contactors while providing reliable disconnection in emergency situations.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent changes the operational state of the disconnecting element from reversible (electromechanical contactor that can be opened and closed multiple times) to irreversible (pyrotechnic element that operates once and cannot be reset). This parameter change ensures that the disconnecting element is used only in genuine emergency situations, avoiding unnecessary activation and extending system reliability.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If an irreversible disconnecting element is used, then aging and heat generation are reduced, but the disconnecting element can only be activated once and requires replacement

Engineering Contradiction:

Improvesafety and reliabilityVSAvoidservice costs and time

Core Design Contradiction:

ReliabilityVSEase of repair

Solution Approach 1:

The patent employs a disposable pyrotechnic disconnecting element that is designed for single-use in emergency situations. While the element itself is consumed and requires replacement, its low cost and simple replacement procedure (disconnecting the high-voltage battery and installing a new element) make the overall repair process efficient and cost-effective compared to maintaining complex electromechanical contactors.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Object-affected harmful factors

If the safety device is activated to disconnect the high-voltage battery, then emergency service personnel are protected, but the disconnecting element cannot be reclosed and requires replacement

Engineering Contradiction:

Improveprotection of emergency service personnelVSAvoidservice time for replacement

Core Design Contradiction:

Object-affected harmful factorsVSLoss of time

Solution Approach 1:

The patent designs the pyrotechnic disconnecting element to be pre-installed and integrated into the high-voltage battery system before any emergency occurs. The element is ready for immediate activation when needed, eliminating the need for complex decision-making or preparation during emergency situations. The replacement procedure is also simplified to be a straightforward swap operation.

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

Enhances safety and reliability by ensuring irreversible disconnection only in emergency conditions, reducing service costs and time, and minimizing heat generation, while maintaining system efficiency and safety.

Implementation Method 1

The disconnecting element can be designed to utilize a pyrotechnic reaction in order to effect separation of contact surfaces of a switch

Methodology Applied

Scientific EffectPyrotechnic reaction: Combustion

Implementation Method 2

separation of contact surfaces of a switch, in particular by friction, melting or vaporization of material in an arc

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS11021065B2High-voltage battery system having a safety device

Publication Date: 2021.06.01 BAYERISCHE MOTOREN WERKE AG

AI summary

A battery system for an electric vehicle has a high-voltage battery, a control unit, and a safety device for disconnecting the high-voltage battery from a high-voltage on-board electrical system of the electric vehicle. The battery system is characterized in that the control unit has two conductor loops, and that the control unit carries out a monitoring of the two conductor loops. Based on the monitoring, the control unit activates the safety device such that the safety device separates the high-voltage battery from the high-voltage vehicle electrical system of the electric vehicle, wherein the safety device has an irreversible separating element.