Motor Thermal Network Feedback for Accurate Component Temperature Estimation
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Solution Overview
Problem
Conventional motor devices inaccurately estimate the temperature of components due to insufficient measurement of heat transfer amounts and directions between adjacent components, leading to low temperature estimation accuracy.
Innovation Solution
A motor device equipped with sensors to detect heat transfer amounts and directions, and a control device that calculates component temperatures using a thermal circuit network, correcting thermal resistances and heat capacities based on actual measurements to improve estimation accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If temperature sensors are attached to some components and thermal circuit network is used for estimation, then temperature estimation can be performed without direct measurement of all components, but temperature estimation accuracy is not high due to inability to accurately estimate heat transfer amount between adjacent components
Solution Approach 1:
The patent applies feedback by using temperature sensors to detect actual temperatures of certain components, then feeding this information back to correct the thermal circuit network model. The control device compares estimated temperatures with sensor measurements and adjusts thermal resistances and heat capacities accordingly, creating a closed-loop system that continuously improves estimation accuracy for all components including those without direct sensors.
Solution Approach 2:
The patent replaces direct physical measurement (mechanical/thermal contact sensors on all components) with a computational model (thermal circuit network). Instead of attaching sensors to every component, the system uses a mathematical model with thermal resistances and heat capacities to estimate temperatures, substituting physical measurement infrastructure with computational estimation that can be refined through feedback.
2Measurement precision
If thermal circuit network with fixed thermal resistances and heat capacities is used, then temperature calculation can be performed efficiently, but heat transfer amount between adjacent components cannot be accurately estimated
Solution Approach 1:
The patent applies dynamics by making the thermal circuit network parameters (thermal resistances and heat capacities) variable rather than fixed. The control device dynamically adjusts these parameters based on feedback from temperature sensors and detected heat transfer amounts, allowing the model to adapt to changing operating conditions while maintaining calculation efficiency through structured updates rather than full recalculations.
Solution Approach 2:
The patent changes the parameters of the thermal circuit network model based on actual measurements. The control device modifies thermal resistances and heat capacities to match detected heat transfer amounts and temperatures, transforming the model from a static theoretical representation to a dynamic empirical model that accurately reflects actual heat transfer conditions in the motor.
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
The motor device achieves accurate temperature estimation of components by directly measuring heat transfer and correcting thermal parameters, enhancing the precision of temperature calculations and expanding the operational limits of the motor.
Implementation Method 1
a sensor for detecting a heat transfer amount and a heat transfer direction with respect to the components composing the motor
Data Source
AI summary
This motor device includes: a motor having components including a stator and a rotor; and a controlling circuitry to control the motor. The motor is provided with temperature sensors to detect a heat transfer amount and a transfer direction about the components. The controlling circuitry includes a temperature calculator to calculate a component temperature based on a thermal circuit network from thermal resistances and heat capacities given for the components. On the basis of actual measured values of the heat transfer amount and the transfer direction obtained by the temperature sensors, the temperature calculator corrects thermal resistances and heat capacities about the components obtained on the basis of the thermal circuit network, and estimates the temperature of each component during driving of the motor.