Rotating Electric Machine Temperature Estimation via Coolant Dissipator
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Solution Overview
Problem
Existing temperature estimation methods for rotating electric machines are inefficient in accurately estimating temperatures of critical components, particularly due to reliance on coolant temperatures before heat exchange, which can lead to inaccuracies in heat dissipation calculations and subsequent component temperature estimation.
Innovation Solution
A temperature estimation apparatus comprising a coolant dissipator, a heat dissipation amount acquisition unit, a coolant temperature acquisition unit, and a temperature estimation unit, which utilizes air speed and coolant flow rate to accurately calculate the temperature of the coolant post-exchange, enabling precise estimation of component temperatures by considering the heat dissipation process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If coolant temperature before heat exchange is used for temperature estimation, then the estimation system is simple, but the temperature estimation accuracy deteriorates
Solution Approach 1:
The patent introduces a thermal model as an intermediary between the coolant temperature measurement and the component temperature estimation. The thermal model processes the coolant temperature data along with other parameters (coolant flow rate, power loss, ambient temperature) to calculate accurate component temperatures, thereby resolving the contradiction between using simple temperature measurements and achieving accurate temperature estimation.
Solution Approach 2:
The patent replaces direct physical temperature sensors in hard-to-reach components with a computational thermal model that substitutes physical measurement with mathematical calculation. This allows temperature estimation in components where physical sensing is difficult, improving measurement precision without proportionally increasing device complexity.
2Measurement precision
If thermal model calculation is used for temperature estimation, then temperature estimation accuracy is improved, but calculation complexity increases
Solution Approach 1:
The patent performs preliminary calculations by pre-establishing the thermal model structure and relationships between parameters. During operation, the system only needs to input readily available measurements (coolant temperature, flow rate, power loss) and the thermal model automatically computes the component temperatures, reducing the perceived calculation complexity during real-time operation.
3Measurement precision
If accurate heat dissipation calculation is implemented, then temperature estimation accuracy is improved, but system complexity increases
Solution Approach 1:
The thermal model serves multiple functions simultaneously: it calculates heat dissipation, estimates component temperatures, and can be used for control decisions. This multi-functionality allows accurate temperature estimation without adding separate dedicated systems, thereby improving measurement precision while limiting the increase in system 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 solution enhances the accuracy of temperature estimation for rotating electric machine components by using coolant temperatures post-exchange, reducing inaccuracies and improving heat dissipation calculations, while minimizing system complexity and energy consumption.
Implementation Method 1
a coolant dissipator configured to cool down a coolant by heat exchange with cooling air outside a rotating electric machine
Implementation Method 2
the coolant cooling down the rotating electric machine
Data Source
AI summary
A temperature estimation apparatus for a rotating electric machine includes a coolant dissipator, a heat dissipation amount calculator, a coolant temperature calculator, and a temperature calculator. The coolant dissipator is to cool down a coolant by heat exchange with a cooling air outside a rotating electric machine. The heat dissipation amount calculator is to calculate heat dissipation amount of the coolant in the coolant dissipator based on a physical quantity correlating with air speed of the cooling air and a physical quantity correlating with flow rate of the coolant. The coolant temperature calculator is to calculate, based on the heat dissipation amount, temperature of the coolant that has passed through the coolant dissipator. The temperature calculator is to calculate, based on the temperature of the coolant, temperature of the rotating electric machine which the coolant cool down.