Battery Pack Power Cutoff Mechanism for Collision Isolation
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Solution Overview
Problem
In electric vehicles, battery packs can deform during collisions, leading to potential fires due to short circuits. The existing battery management systems (BMS) may fail to disconnect power in such scenarios, risking electric shock or further damage.
Innovation Solution
A battery pack design that includes a frame portion, multiple battery modules, a battery disconnect unit (BDU), and a power cutoff portion. The power cutoff portion features a guide plate, power terminals, a connector portion, and a weight member that moves to block electrical connections during a vehicle collision, ensuring power is automatically cut off.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the battery management system (BMS) is used to cut off the contactor, then power can be blocked in normal operation, but the BMS may fail to operate during collision impact
Solution Approach 1:
The power cutoff function is segmented into two independent systems: the BMS for normal operation and the weight member mechanism for collision events. This segmentation ensures that the collision response does not depend on the BMS operational status, improving reliability during accidents.
Solution Approach 2:
The weight member acts as a mechanical intermediary that directly responds to collision forces and physically blocks the connector, providing a fail-safe cutoff mechanism that operates independently of the BMS electrical control system.
2Object-affected harmful factors
If the contactor remains in a closed state during collision, then electrical connection is maintained, but this causes risk of electric shock or short circuit
Solution Approach 1:
The weight member mechanism is pre-positioned to block the connector when collision force is applied, creating a preliminary protective action that prevents electric shock risk before it can materialize during collision events.
Solution Approach 2:
The collision impact force, which is harmful to the battery pack, is converted into a useful mechanical force that drives the weight member to block the connector, automatically cutting off power when needed most during the harmful event.
3Reliability
If a weight member mechanism is added for automatic power cutoff, then collision safety is improved, but device complexity increases
Solution Approach 1:
The weight member mechanism is self-actuating, using the collision force itself to trigger the power cutoff action without requiring external sensors, control systems, or additional power sources, thereby minimizing added complexity.
Solution Approach 2:
The complex electrical control system is replaced with a simple mechanical linkage system where the weight member directly physically blocks the connector through pure mechanical motion, reducing overall system complexity while improving reliability.
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 solution effectively prevents accidents such as explosions by automatically disconnecting power to the battery pack during a collision, thereby mitigating the risk of fire and electric shock.
Implementation Method 1
a weight member movable along the guide plate in an event of a vehicle impact, the weight member being configured to transfer an impact force of the vehicle to the connector portion
Implementation Method 2
a connector portion slidably inserted between the first power terminal and the second power terminal and configured to electrically connect the first power terminal and the second power terminal to each other
Data Source
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AI summary
A battery pack includes a frame portion configured to be installed in a vehicle, with a plurality of battery modules accommodated in the frame portion. A battery disconnect unit (BDU) is installed inside of the frame portion, with the battery disconnect unit being configured to transmit or block a voltage of the battery module. A power cutoff portion is configured to electrically connect the battery disconnect unit and the battery module and to block an electrical connection of the battery module and the battery disconnect unit in an event of a vehicle collision.