Induction Heating Control via Electromagnetic Thermal Estimation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Induction heating systems face challenges in accurately estimating the temperature of cooking utensils and their contents without direct temperature measurement, relying on qualitative methods that are not reliable for quantitative control.
Innovation Solution
A method that uses electromagnetic variables to estimate thermal states by establishing a link between these variables and thermal properties, allowing for open-loop operation after initial parameter estimation, reducing computational effort and the need for thermal measurements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If continuous closed-loop compensation is performed throughout the entire cooking process, then temperature estimation accuracy is improved, but computational effort and system complexity increase significantly
Solution Approach 1:
The patent applies preliminary action by performing parameter identification and thermal model calibration during the initial phase of cooking, before the main cooking process begins. The system identifies thermal parameters (heat capacity, thermal conductivity, mass) of the cooking utensil and its contents during a preliminary heating phase, then uses these pre-determined parameters throughout the entire cooking process. This eliminates the need for continuous closed-loop compensation while maintaining accurate temperature estimation, as the thermal characteristics are established in advance and remain valid for the duration of cooking.
2Measurement precision
If direct temperature sensors are installed to measure pot and food temperature, then temperature measurement accuracy is improved, but device complexity and cost increase
Solution Approach 1:
The patent replaces the mechanical/physical temperature sensors with an electromagnetic field-based measurement system. Instead of using thermal sensors that physically contact the pot or food, the system uses electromagnetic variables (current, voltage, power factor) measured from the induction heating coil to infer thermal states. The system establishes relationships between electromagnetic parameters and thermal properties through thermal models, allowing non-contact temperature estimation of the cooking utensil and its contents without any physical sensors being installed in the cooking area.
Solution Approach 2:
The patent introduces electromagnetic variables as intermediaries between the heating system and thermal states. Rather than directly measuring temperature, the system measures electromagnetic parameters (current, voltage, power factor) which serve as intermediaries to infer thermal information. The thermal model acts as a mediator that translates electromagnetic measurements into temperature estimates, enabling indirect but accurate measurement of thermal states without physical contact or additional sensors.
3Device complexity
If qualitative evaluation methods are used to assess cooking state, then device complexity is reduced, but reliability of temperature information deteriorates
Solution Approach 1:
The patent transforms qualitative evaluation into quantitative measurement by changing the parameters being measured from subjective indicators to objective electromagnetic variables. Instead of relying on qualitative assessments (visual inspection, taste testing, or subjective feedback), the system measures objective electromagnetic parameters (current, voltage, power factor) and uses thermal models to calculate specific quantitative thermal values such as temperature, heat capacity, and mass. This parameter transformation enables reliable quantitative temperature information while maintaining relatively simple system architecture, as the electromagnetic measurements are naturally obtained during normal heating operation without additional complexity.
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
Enables reliable quantitative monitoring and control of thermal states in induction cooktops, improving the ability to detect boiling, empty pots, and maintain specific temperatures without introducing additional sensors, thus enhancing cooking precision and efficiency.
Implementation Method 1
induction heating system with induction coil
Implementation Method 2
induction heating system
Data Source
AI summary
A method for controlling an induction heating system, particularly an induction heating system of a cooktop on which a cooking utensil with a certain contents is placed for heating/cooking purposes, comprises the steps of carrying out a predetermined number “n” of electrical measurements of a first electrical parameter of the heating system on the basis of a predetermined electrical value of a second electrical parameter, “n” being ≥2, repeating the above set of measurements at a predetermined time after the first measurements, and estimating at least one thermal parameter of the heating system, particularly of the contents of the cooking utensil, on the basis of the above set of measurements.