Power Module Temperature Estimation Using Thermal Cross-Coupling Filters
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Solution Overview
Problem
Existing power module controllers in hybrid and electric vehicles face inaccuracies in temperature estimation at low fundamental operating frequencies, leading to potential overheating and reduced component reliability due to assumptions based on high-frequency thermal averaging.
Innovation Solution
A method is introduced to calculate power dissipation values for components, apply filters to estimate temperatures, and account for cross-coupling effects from neighboring components, allowing for accurate temperature estimation even at low frequencies and enabling operational adjustments if thresholds are exceeded.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If thermal averaging assumption is used for temperature estimation, then the system is simple to operate, but temperature estimation accuracy deteriorates at low frequencies
Solution Approach 1:
The patent changes the estimation parameter from simple thermal averaging to a model-based approach that incorporates fundamental frequency and duty cycle parameters. This allows the system to adapt the temperature estimation method based on operating conditions, maintaining accuracy across both high and low frequency ranges while keeping the control system manageable.
Solution Approach 2:
The patent introduces an intermediate thermal model that acts as a mediator between the simple averaging method and the actual thermal behavior. This model uses power dissipation calculations and thermal impedance networks to bridge the gap, providing accurate temperature estimates without requiring complex direct measurement systems.
2Device complexity
If simple thermal averaging is used, then device complexity is reduced, but reliability deteriorates due to inaccurate temperature estimation
Solution Approach 1:
The patent replaces physical thermal sensors with a computational thermal model. Instead of using complex hardware-based temperature measurement systems, the invention uses mathematical models that calculate temperature based on electrical parameters (power dissipation, fundamental frequency, duty cycle), thereby maintaining low device complexity while improving reliability.
Solution Approach 2:
The system uses its own operational parameters (power dissipation, switching frequency, duty cycle) to self-determine temperature conditions. This self-service approach eliminates the need for external temperature sensors and complex measurement systems, keeping device complexity low while ensuring reliable temperature-aware operation.
3Device complexity
If high-frequency thermal averaging assumption is made, then temperature estimation is simplified, but harmful thermal effects increase due to overheating at low frequencies
Solution Approach 1:
The patent makes the temperature estimation method dynamic by adapting it to the operating frequency. At high frequencies, the system uses simplified averaging methods, while at low frequencies, it transitions to a more sophisticated model-based approach. This dynamic adaptation prevents thermal overheating at low frequencies while maintaining estimation simplicity at high frequencies.
Solution Approach 2:
The system takes preliminary action by calculating expected temperature rise based on power dissipation and thermal models before actual overheating occurs. This allows the controller to anticipate thermal issues at low frequencies and adjust operation accordingly, preventing harmful thermal effects before they manifest.
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 provides more accurate temperature estimation and prevents overheating by accounting for thermal cross-coupling, enhancing the reliability of power module components during low-frequency operations.
Implementation Method 1
A first filter is applied to the power dissipation value associated with a selected component to determine its estimated temperature
Implementation Method 2
For each of the neighboring components located adjacent to the selected component, a cross-coupling temperature is estimated by applying other filters to each of the power dissipation values for the neighboring components
Data Source
AI summary
Methods and systems are provided for modeling temperature characteristics of components in a system such as a power module for a hybrid or electric vehicle. A power dissipation value is calculated for each of the components in the system. A first filter is applied to the power dissipation value associated with a selected component to determine its estimated temperature. For each of the neighboring components located adjacent to the selected component, a cross-coupling temperature is estimated by applying other filters to each of the power dissipation values for the neighboring components. The estimated temperature of the selected component and the estimated cross-coupling temperatures for each of the neighboring components can then be added to thereby estimate the operating temperature for the selected component. Further, the operation of the system may be adjusted if the operating temperature determined for the selected component exceeds a threshold value.