Heating Resistor Active-Layer Temperature Estimation Without Sensors
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Solution Overview
Problem
Heating resistors in electric vehicles face challenges in accurately determining the temperature of their active layers without sensors, leading to inefficient operation and potential damage due to excess temperatures, especially under dynamic current loads.
Innovation Solution
A method that determines the temperature of the active layer by measuring instantaneous current and voltage values, calculating electrical resistance, and using stored resistance-temperature pairs to estimate temperature, allowing for continuous and accurate temperature monitoring without additional sensors, and predicting thermal absorption capacity to manage braking energy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a temperature sensor is installed in the active layer to accurately measure temperature, then temperature measurement precision is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent replaces the mechanical/physical temperature sensor system with an electrical measurement system. By measuring the electrical resistance of the active layer and using the known resistance-temperature relationship, the temperature is determined indirectly through electrical properties rather than direct thermal contact, thereby eliminating the need for separate temperature sensors and reducing device complexity
Solution Approach 2:
The patent introduces electrical resistance as an intermediary parameter to determine temperature. Instead of directly measuring temperature with a sensor, the system measures electrical resistance (which has a known relationship with temperature) and calculates temperature from this intermediate measurement, effectively using resistance as a mediator between the measurement system and the temperature parameter
2Device complexity
If no temperature sensor is installed to reduce complexity and cost, then device complexity is reduced, but temperature measurement precision deteriorates leading to excessive safety margins
Solution Approach 1:
The patent replaces the need for temperature sensors by substituting temperature measurement with electrical resistance measurement. Since the active layer's resistance varies predictably with temperature, this substitution maintains measurement precision while eliminating complex sensor installations and associated safety margin constraints
Solution Approach 2:
The patent makes the electrical measurement system multi-functional by using it for both current control and temperature determination. The same electrical connections and measurements used for controlling the heating current also provide the data needed for temperature assessment, eliminating the need for separate temperature sensing infrastructure and improving overall system efficiency
3Reliability
If a large temperature gap is maintained to avoid excess temperatures under dynamic loads, then reliability is improved, but productivity decreases due to reduced heating capacity utilization
Solution Approach 1:
The patent implements continuous feedback by repeatedly measuring the electrical resistance and calculating the current temperature. This real-time feedback allows the system to dynamically adjust the heating current to maintain temperatures close to the maximum permitted value without exceeding safety limits, thereby maximizing heating capacity utilization while ensuring reliability under dynamic load conditions
Solution Approach 2:
The patent makes the temperature control dynamic by continuously monitoring resistance changes and adjusting the heating current in real-time. This dynamic control allows the system to respond to changing thermal conditions and load requirements, maintaining optimal operating temperatures without excessive safety margins and maximizing the utilization of heating capacity
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 measurement speed and accuracy, enabling the heating resistor to operate closer to its maximum power capacity while preventing damage from excess temperatures, and optimizes energy absorption and braking strategies.
Implementation Method 1
Generated electrical energy is in particular able to be converted, via the heating resistor, into heat that is able to be dissipated via a cooling circuit
Implementation Method 2
heat that is able to be dissipated via a cooling circuit
Implementation Method 3
heat that is able to be dissipated via a cooling circuit
Data Source
AI summary
Various embodiments include method for determining a temperature of an active layer of a heating resistor for a recuperation system of a motor vehicle comprising: determining an instantaneous value of a current flowing through the active layer of the heating resistor at a first time; determining an instantaneous value of a voltage present on the active layer at the first time; calculating an instantaneous value of an electrical resistance based on the determined instantaneous value of the current and the determined instantaneous value of the voltage; and determining an instantaneous value of a temperature of the active layer from the calculated value of the electrical resistance.