Vehicle Rotary Electric Machine Temperature Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing rotary-electric-machine temperature estimation systems for vehicles face decreased estimation accuracy due to changes in vehicle body posture, which affect the contact state of the refrigerant with the stator coil, leading to inaccurate temperature measurements.
Innovation Solution
A temperature estimation system that includes a rotary electric machine, a cooler, a temperature sensor, and a controller, where the controller adjusts a temperature correction value based on changes in vehicle posture using predefined maps to accurately estimate the stator coil temperature, even when the vehicle is tilted.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the vehicle body posture changes, then the contact state of refrigerant with stator coil changes, but the temperature measurement accuracy deteriorates
Solution Approach 1:
The patent applies the dynamics principle by making the temperature correction value dynamic rather than static. The controller automatically adjusts the temperature correction value based on detected vehicle posture changes (tilting angles). This allows the temperature estimation system to adapt to different vehicle postures during operation, resolving the contradiction between adaptability to posture changes and temperature measurement accuracy.
2Measurement precision
If the temperature correction value is adjusted according to vehicle posture, then the temperature estimation accuracy improves, but the device complexity increases
Solution Approach 1:
The patent applies the parameter changes principle by modifying the temperature correction value parameter based on vehicle posture conditions. Instead of changing the physical structure or adding complex hardware, the system adjusts the correction value parameter according to detected tilting angles. This resolves the contradiction by improving temperature estimation accuracy through parameter adjustment rather than increasing device complexity.
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 approach improves the estimation accuracy of the stator coil temperature by accounting for changes in vehicle posture, ensuring precise temperature measurement and preventing overheating of the rotary electric machine.
Implementation Method 1
a cooler configured to cool off the stator coil by refrigerant injected from an injection outlet
Data Source
AI summary
Provided is a rotary-electric-machine temperature estimation system for a vehicle. The temperature estimation system includes a rotary electric machine, a cooler, a temperature sensor, and a controller. The rotary electric machine is fixed to a vehicle body of the vehicle and provided in the vehicle. The rotary electric machine includes a stator coil. The cooler has an injection outlet for injecting refrigerant, and cools off the stator coil by the refrigerant thus injected from the injection outlet. The temperature sensor measures a temperature of the stator coil. The controller estimates an actual temperature of the stator coil by use of the measured temperature and a preset temperature correction value. The controller changes the temperature correction value according to a change in a posture of the vehicle body.