Dynamic Motor Temperature Estimation via Parameter Adaptation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for estimating motor coil temperature do not account for manufacturing variations and aging degradation, leading to inaccurate temperature estimation in rotating electric machines.
Innovation Solution
An apparatus with a control unit that compares physical quantities responsive to power supplied to winding sets, modifies parameters for temperature estimation, and includes a temperature estimator to accurately account for variations caused by manufacturing and aging degradation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a fixed time constant and gain determined by actual measurements are continuously used for temperature estimation, then the temperature estimation method is simple, but the temperature estimation accuracy deteriorates due to manufacturing variations and aging degradation
Solution Approach 1:
The patent applies dynamics by making the time constant and gain dynamic rather than fixed. The time constant is adjusted based on the detected temperature value, with different time constants selected for different temperature ranges. The gain is also dynamically adjusted based on the relationship between detected temperature and estimated temperature. This dynamic adjustment allows the estimation system to adapt to manufacturing variations and aging degradation, resolving the contradiction between simplicity and accuracy.
Solution Approach 2:
The patent changes the parameters (time constant and gain) used in the temperature estimation based on actual temperature detection results. When the detected temperature falls within certain ranges or when specific relationships between detected and estimated temperatures are observed, the parameters are modified accordingly. This parameter adaptation enables accurate temperature estimation despite manufacturing variations and aging, while maintaining a relatively simple estimation framework.
2Device complexity
If temperature estimation does not account for manufacturing variations and aging degradation, then the estimation method is simple, but the reliability of temperature control deteriorates
Solution Approach 1:
The patent implements feedback by continuously comparing the detected temperature with the estimated temperature and using this comparison to adjust the estimation parameters. The detected temperature serves as feedback that informs adjustments to the time constant and gain, creating a closed-loop system that adapts to manufacturing variations and aging degradation. This feedback mechanism enhances reliability while keeping the overall method relatively simple.
Solution Approach 2:
The patent modifies the estimation parameters (time constant and gain) based on feedback from temperature detection, enabling the system to adapt to manufacturing variations and aging degradation. This parameter adaptation improves temperature control reliability without significantly complicating the estimation method.
3Productivity
If current limiting is applied without accurate temperature estimation, then the motor performance is maintained, but overheating cannot be prevented due to inaccurate temperature data
Solution Approach 1:
The patent replaces direct temperature measurement with an estimation system that uses electrical parameters (current, voltage, time constant) to infer temperature. This substitution allows for continuous temperature monitoring without physical temperature sensors in the motor, enabling accurate temperature-based current limiting that prevents overheating while maintaining motor performance.
Solution Approach 2:
The patent uses feedback from the temperature estimation system to control current limiting. The estimated temperature continuously informs the current limiting decision, allowing the system to maintain motor performance when temperatures are acceptable and prevent overheating when temperatures rise, creating an adaptive protection mechanism.
Data Source
AI summary
An apparatus for controlling operation of a rotating electric machine including a plurality of winding sets. The apparatus includes a plurality of inverters for the respective winding sets and a control unit. The control unit includes a physical quantity comparator configured to compare physical quantities that are responsive to power supplied to the respective winding sets, a temperature estimator configured to estimate system temperatures that are temperatures of respective systems, each of which systems is a combination of a respective one of the plurality of winding sets and its associated components, and a parameter modifier configured to modify a parameter used to estimate a temperature of each system in response to a result of comparison between the physical quantities.