Electric Compressor Thermal Protection via Carrier Frequency Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Integrated electric compressors in vehicles face heat damage issues due to high power consumption and overcurrent, which can lead to component failure or fire, as existing protection methods either fail to consider temperature or reduce compressor output.
Innovation Solution
An electric compressor with a control system that compares temperature and current characteristics to stop or reduce the electric motor's load, adjusting rotational speed and carrier frequency to protect high voltage components from heat damage based on their capability, using temperature and current detectors to implement protection control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the switching element supplies large electric power to control motor rotational speed, then the motor can operate at desired speeds, but power consumption becomes too high causing overcurrent that damages high voltage components
Solution Approach 1:
The patent changes the operating parameters of the switching element by dynamically adjusting carrier frequency based on temperature conditions. At lower temperatures, higher carrier frequencies enable effective motor control, while at elevated temperatures, the carrier frequency is reduced to minimize power consumption and prevent overcurrent damage, thus resolving the contradiction between power supply capability and component reliability
Solution Approach 2:
The patent implements dynamic operation by continuously monitoring component temperature and adaptively adjusting the carrier frequency in real-time. This dynamic parameter adjustment allows the system to optimize between power delivery and thermal protection, preventing static overheating issues while maintaining motor control effectiveness across varying operating conditions
2Reliability
If protection control stops the electric motor when temperature exceeds limits, then component heat damage is prevented, but compressor output is reduced
Solution Approach 1:
Instead of completely stopping the motor when temperature limits are approached, the patent applies partial protection by reducing the carrier frequency to a lower operational level. This partial action maintains compressed air output while sufficiently reducing power consumption to prevent thermal damage, avoiding the excessive action of complete shutdown
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 prevents heat damage to components by reducing load and adjusting operational parameters, ensuring the compressor operates within safe temperature and current limits, thereby extending component life and maintaining performance.
Implementation Method 1
a cooling effect by the refrigerant falls below calorific values of the electrical circuit and the electric motor
Implementation Method 2
calorific values of the electrical circuit and the electric motor
Data Source
Figure 1
Figure 2
Figure 3A~3B
AI summary
There is provided an electric compressor that can protect a component to be protected from heat damage according to a capability of the component. The electric compressor 10 includes a compression mechanism 11, an electric motor 12 that drives the compression mechanism 11, and a control portion 13 that controls to drive the electric motor 12, incorporated into a single casing, and further includes a temperature detector 14 that detects a temperature of one or more components that constitute one or both of the control portion 13 and the electric motor 12, and a current detector 15 that detects a current flowing through the component. When the temperature detected by the temperature detector 14 is a temperature Td, the current detected by the current detector 15 when the temperature detector 14 detects the temperature Td is a current Id, and a current corresponding to the temperature Td at a temperature characteristic relating to the current specific to the component is a current Ia(Td), the control portion 13 stops driving the electric motor 12 on the basis of a result of comparison between Ia(Td) and Id.