Vehicle Low-Voltage Battery Management for Emergency Power
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hybrid-electric and conventional vehicles face challenges in ensuring the low-voltage battery has sufficient energy to power critical systems during emergency maneuvers, particularly when the battery's state of charge is depleted, risking vehicle halt and safety.
Innovation Solution
A power system that includes a low-voltage battery electrically coupled to a powertrain and a computer programmed to put the vehicle in a minimal risk condition by managing the state of charge, involving thresholds for energy reduction, recharge, and load shedding to maintain power availability during emergencies.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the low-voltage battery capacity is increased to ensure sufficient energy for emergency maneuvers, then vehicle safety and reliability are improved, but vehicle weight and cost increase
Solution Approach 1:
The system proactively manages the low-voltage battery state of charge by preemptively recharging the battery when the high-voltage battery has sufficient capacity, ensuring sufficient energy is available before an emergency maneuver is needed rather than waiting for a critical low-state-of-charge condition
Solution Approach 2:
The control system continuously monitors the state of charge of both the low-voltage and high-voltage batteries, using this feedback to dynamically adjust power distribution and trigger recharging operations when conditions are favorable, creating a closed-loop control system that maintains battery readiness
2Reliability
If the low-voltage battery capacity is increased to ensure sufficient energy for emergency maneuvers, then vehicle safety and reliability are improved, but device complexity and cost increase
Solution Approach 1:
The high-voltage battery system serves multiple functions: it provides power for propulsion and simultaneously serves as a charging source for the low-voltage battery during normal operation, eliminating the need for a dedicated charging system and reducing overall system complexity
Solution Approach 2:
The system proactively manages the low-voltage battery state of charge by preemptively recharging the battery when the high-voltage battery has sufficient capacity, ensuring sufficient energy is available before an emergency maneuver is needed rather than waiting for a critical low-state-of-charge condition
3Power
If the DC/DC converter capacity is increased to supply more power to loads, then power availability is improved, but device complexity and cost increase
Solution Approach 1:
Instead of designing the DC/DC converter to handle the maximum possible power demand, the system uses the low-voltage battery to supplement power during high-demand scenarios, allowing the DC/DC converter to be sized for typical operating conditions rather than peak emergency conditions
Solution Approach 2:
The low-voltage battery acts as an intermediary energy storage device between the DC/DC converter and the loads, absorbing excess power during normal operation and providing supplemental power during high-demand scenarios, thereby reducing the power rating requirements for the DC/DC converter
Data Source
AI summary
A vehicle includes a low-voltage battery electrically coupled to a powertrain, and a computer programmed to put the vehicle in a minimal risk condition in response to a state of charge of the low-voltage battery falling below a threshold. The vehicle may further include a DC/DC converter electrically coupled to the powertrain and to the low-voltage battery, and a high-voltage battery electrically coupled to the powertrain.