Electric Vehicle Battery Temperature Estimation During Sensor Failure
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Solution Overview
Problem
Electrically driven vehicles fail to determine appropriate battery temperature during an abnormality in the temperature sensor, leading to potential battery damage and inability to perform emergency drives.
Innovation Solution
The vehicle employs a control device that sets a drivable time using a reference temperature, initially using the pre-abnormality temperature and subsequently using a temperature derived from inter-terminal voltage and current, to manage battery power supply and prevent damage during sensor abnormalities.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the temperature sensor abnormality is detected, then the system cannot accurately detect battery temperature, but continuing power supply may cause battery damage
Solution Approach 1:
The patent introduces an intermediary estimation method using battery resistance (derived from voltage and current measurements) as a mediator to infer battery temperature when the temperature sensor is abnormal. This indirect measurement approach allows the system to continue operating while maintaining safety monitoring capability.
Solution Approach 2:
The system changes from direct temperature measurement to indirect temperature estimation by measuring electrical parameters (voltage and current) and calculating battery resistance, which correlates with temperature. This parameter substitution enables continued operation during sensor failure.
2Productivity
If the temperature sensor abnormality is detected, then the system stops power supply to protect the battery, but this prevents emergency drive operation
Solution Approach 1:
The patent uses battery resistance as an intermediary parameter to maintain temperature monitoring capability during sensor failure. By measuring voltage and current to calculate resistance, the system can estimate temperature and make informed decisions about continued operation during emergency drives.
Solution Approach 2:
The system uses its existing electrical measurement capabilities (voltage and current sensors) to self-diagnose and self-monitor battery temperature without requiring the failed temperature sensor. This self-service approach maintains monitoring functionality using available resources.
3Productivity
If the drivable time is extended for emergency drive, then the emergency drive capability is improved, but the risk of battery damage increases
Solution Approach 1:
The system continuously monitors battery resistance during emergency drive and compares it against temperature thresholds. This feedback mechanism allows the system to extend drivable time while maintaining safety by detecting temperature changes through resistance variations and stopping when limits are reached.
Solution Approach 2:
The drivable time limit is not fixed but dynamically adjusted based on real-time battery resistance measurements. The system can extend operation as long as resistance indicates acceptable temperature, creating a flexible time limit that balances emergency drive needs with battery safety.
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 configuration enables safe emergency driving while minimizing battery damage by setting appropriate drivable times based on reliable temperature references, even with a faulty temperature sensor.
Implementation Method 1
a temperature sensor configured to detect temperature of the battery
Implementation Method 2
to use a temperature obtained by applying a resistance value based on an inter-terminal voltage of the battery and an electric current flowing in the battery, to a correlation between battery resistance and battery temperature, as the reference temperature
Data Source
AI summary
In the event of an abnormality occurring in a temperature sensor that is used to detect the temperature of a battery, an electrically driven vehicle sets a drivable time by using a reference temperature of the battery and gives permission for emergency drive until a driving time of the electrically driven vehicle reaches the drivable time. When the reference temperature is used for the first time since the occurrence of the abnormality in the temperature sensor, a temperature detected before the occurrence of the abnormality in the temperature sensor is used as the reference temperature. When the reference temperature is used for the second or subsequent time since the occurrence of the abnormality in the temperature sensor, a temperature obtained by applying a resistance value based on an inter-terminal voltage of the battery and an electric current flowing in the battery, to a correlation between battery resistance and battery temperature is used as the reference temperature.