EV Cooling Circuit Thermal Diagnosis for Sensor Fault Detection
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Solution Overview
Problem
Current methods for diagnosing the efficiency of low temperature cooling systems in electric vehicles rely on electronic sensors, which can fail, leading to erroneous information and potential critical thermal situations, necessitating a high-performance monitoring system to detect anomalies and prevent overheating.
Innovation Solution
A method involving the measurement of heat transfer fluid temperatures in both cooling circuits, a weighted temperature calculation, and threshold comparison to detect anomalies, with activation of diagnostic steps and protective measures such as increased fluid flow and alerts to prevent overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If electronic sensors are used to measure temperature in cooling systems, then temperature measurement capability is provided, but sensor failure can lead to erroneous information and critical thermal situations
Solution Approach 1:
The patent introduces an intermediary diagnostic method that uses mathematical models and multiple temperature measurements (from different sensors and locations) to verify the validity of sensor readings. The system calculates expected temperatures based on thermal models and compares them with actual sensor readings to detect sensor failures, thereby maintaining reliability even when sensors are present
Solution Approach 2:
The system implements feedback by continuously monitoring temperature measurements, comparing them against model predictions and threshold values, and triggering diagnostic routines when discrepancies are detected. This closed-loop feedback mechanism enables real-time detection of sensor failures and prevents erroneous temperature data from compromising thermal management
2Reliability
If a monitoring system is implemented to detect sensor failures, then thermal management reliability is improved, but system complexity increases
Solution Approach 1:
The diagnostic system performs self-verification by using its own temperature measurements and thermal models to detect sensor failures without requiring external monitoring equipment. The system serves itself by validating its sensor readings through mathematical consistency checks and cross-referencing multiple measurement points
Solution Approach 2:
The control unit that manages thermal control functions is also used to execute diagnostic routines and perform mathematical calculations for sensor validation. This multi-functionality allows the same hardware to serve both thermal management and diagnostic purposes, avoiding the need for separate dedicated diagnostic equipment
3Measurement precision
If diagnostic routines are executed continuously to detect anomalies, then detection capability is improved, but processing time and computational load increase
Solution Approach 1:
The diagnostic routine is executed periodically at predetermined intervals rather than continuously. The control unit performs thermal diagnostic measurements at scheduled times, balancing the need for accurate anomaly detection with the need to minimize processing time and computational load on the system
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 enhances thermal management by detecting anomalies and preventing overheating, ensuring reliable thermal data and regulatory compliance, thereby protecting critical components and maintaining vehicle performance.
Implementation Method 1
a heat transfer fluid cooling system
Implementation Method 2
The thermal state of these components directly impacts the performance
Implementation Method 3
These electrical circuits, as well as the battery, are under significant stress, causing the temperature to rise due to the Joule effect
Data Source
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AI summary
The present invention relates to a method for diagnosing a malfunction of a vehicle cooling system, in particular an electric motor and associated electrical power elements, such as an inverter, on-board charger. The method comprises estimating an estimated weighted temperature (424) which is determined from a barycentric calculation of first and second measured temperatures (422, 423), determining a threshold (426) by calculating the minimum between, on the one hand, an outside temperature (425) in an environment of the vehicle and, on the other hand, the second temperature (423), comparing (427) the weighted temperature (424) with said threshold (426), and if the weighted temperature (424) is detected to be lower than said threshold (426), a step of activating a diagnosis (200) of a malfunction of the cooling system.