Electric Compressor Temperature Estimation via Motor Speed
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electric compressors face challenges in accurately measuring the temperature of the power element when the temperature measurement section is disposed away from it, leading to indeterminacy and potential damage due to abrupt temperature increases, as the influence of refrigerant heat affects both the power element and the measurement section differently.
Innovation Solution
An electric compressor design that includes a motor, a power element, a temperature measurement section on a substrate, and a control section that estimates the power element's temperature based on the motor's rotational speed and measured temperature, allowing for accurate temperature estimation and overheat protection even when the measurement section is not directly on the power element.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the temperature measurement section is disposed directly in the power element, then the temperature measurement precision is improved, but the device complexity and ease of manufacture deteriorate due to reduced degree of freedom in component arrangement
Solution Approach 1:
The substrate serves as an intermediary that thermally couples the power element to the temperature measurement section. The substrate conducts heat from the power element to the temperature measurement section, enabling indirect temperature measurement while maintaining measurement precision and providing design flexibility.
2Ease of manufacture
If the temperature measurement section is disposed away from the power element on substrate, then the ease of manufacture and device complexity are improved, but the measurement precision deteriorates due to indeterminacy from differential refrigerant heat influence
Solution Approach 1:
The substrate acts as a thermal intermediary that compensates for the spatial separation between the power element and temperature measurement section. By conducting heat through the substrate, the system maintains accurate temperature measurement despite the distance, while also providing manufacturing flexibility.
Solution Approach 2:
The system changes the thermal parameter configuration by using the substrate's thermal conduction properties to transfer heat from the power element to the temperature measurement section. This parameter change enables accurate temperature measurement at a distance while maintaining ease of manufacture.
3Ease of operation
If the temperature measurement section is disposed away from the power element, then the ease of operation is improved, but the reliability deteriorates due to inability to follow abrupt temperature increases
Solution Approach 1:
The substrate serves as a thermal intermediary that rapidly conducts heat from the power element to the temperature measurement section. This thermal coupling ensures that the temperature measurement section follows abrupt temperature increases reliably, maintaining overheat protection functionality while providing operational flexibility.
Solution Approach 2:
The substrate pre-establishes a thermal conduction path between the power element and temperature measurement section, enabling the temperature measurement section to respond proactively to temperature changes. This preliminary thermal coupling ensures reliable overheat detection before damage occurs.
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 enables the electric compressor to effectively follow temperature changes of the power element, reducing the risk of deterioration or damage by correcting the measured temperature with the motor's rotational speed, thereby ensuring reliable operation and preventing overheating.
Implementation Method 1
a temperature measurement section (34) to measure a temperature of a substrate (36) on which the power element (31) is disposed
Implementation Method 2
the temperature of the power element itself is affected by the amount of heat of the refrigerant through the casing
Implementation Method 3
the power element is disposed near the casing surrounding the refrigerant in order to release the self-heating by heat exchange with the refrigerant
Data Source
AI summary
An electric compressor capable of following temperature changes of a power element even if a temperature measurement unit is disposed separately from the power element. In the electric compressor, the temperature measurement unit (34) measures the temperature of a substrate (36) on which the power element (31) is disposed. A rotational speed detection unit (35) detects the rotational speed of a motor. A control unit (33) estimates the temperature of the power element (31) on the basis of the rotational speed of the motor detected by the rotational speed detection unit (35) and the temperature measured by the temperature measurement unit (34).