Battery Contactor Thermal Control Using Model-Based Power Limiting
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing systems for electric vehicles lack effective methods to measure and manage the temperature of contactors connecting high-voltage batteries and motors, which can lead to inefficiencies and potential damage due to excessive heat.
Innovation Solution
A system that includes a controller responsive to temperature data, using a thermal model to estimate the contactor temperature and adjust power output from the battery to the motor based on thermal resistivity and other parameters, thereby mitigating excessive heat by reducing power when the contactor temperature exceeds a threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If power output from the battery to the motor is increased, then productivity is improved, but the contactor temperature increases leading to potential damage
Solution Approach 1:
The system performs preliminary temperature estimation of the contactor using a thermal model before damage occurs. The controller continuously monitors estimated contactor temperature and proactively reduces power output when the temperature approaches dangerous levels, preventing thermal damage before it happens.
Solution Approach 2:
The system implements a feedback mechanism where the controller continuously estimates contactor temperature based on thermal models and feeds this information back to adjust power output. When the estimated temperature exceeds a threshold, the controller reduces power, creating a closed-loop control system that balances productivity and thermal safety.
2Reliability
If contactor temperature is monitored and managed, then reliability is improved, but device complexity increases due to additional sensors and systems
Solution Approach 1:
The system uses a thermal model as an intermediary to estimate contactor temperature without requiring direct physical sensors on the contactor. The thermal model acts as a virtual sensor, calculating temperature based on measurable parameters like battery temperature, current, and thermal resistivity, thereby avoiding the complexity of direct contactor temperature sensing.
Solution Approach 2:
The invention replaces the need for physical temperature sensors and direct mechanical measurement systems with a computational thermal model. Instead of using physical sensors that would add complexity, the system uses mathematical models and existing sensor data to estimate contactor temperature, substituting mechanical sensing with computational analysis.
3Temperature
If power output is reduced to manage contactor temperature, then temperature is controlled, but productivity decreases
Solution Approach 1:
The system dynamically adjusts power output based on real-time contactor temperature estimates. Rather than maintaining a fixed power level or简单地 reducing power whenever temperature rises, the controller continuously adapts power output to match thermal conditions, allowing maximum power when temperatures are safe and reducing power only when necessary, thus optimizing the balance between temperature control and productivity.
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
Effectively manages contactor temperature by reducing power output when necessary, preventing overheating and ensuring safe and efficient operation of the vehicle's power system.
Implementation Method 1
a thermal resistivity of one or more components other than the battery and motor in a vicinity of the contactor
Implementation Method 2
decreasing power output from the battery to the motor responsive to the temperature exceeding a threshold
Data Source
AI summary
Responsive to data indicative of a temperature of a contactor connecting a battery and motor exceeding a threshold, a controller decreases power output from the battery to the motor. The data include parameters indicative of a temperature of the battery, a resistance of an electrical component between the battery and motor, and a thermal resistivity of one or more components other than the battery and motor in a vicinity of the contactor.