Induction Heating Load Detection Using Dual-Frequency Resonance
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Solution Overview
Problem
Users face difficulties in determining whether an object is suitable for induction heating, leading to potential power wastage when non-inductive objects are used on induction heating devices.
Innovation Solution
An induction heating device employs a dual-frequency resonant current measurement method to accurately identify the type of object on the heating surface by comparing resonant current values at different frequencies, using a determination unit to confirm the inductive-heating property through a double determination process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the induction heating device applies power without verifying object compatibility, then the device can operate continuously, but unnecessary power consumption occurs when non-compatible objects are placed on the device
Solution Approach 1:
The system performs preliminary detection of object compatibility by measuring resonant current at different frequencies before applying full heating power. This preliminary action identifies whether the object has magnetic properties suitable for induction heating, preventing energy waste by avoiding operation with incompatible objects
2Ease of operation
If the device uses a single frequency measurement to determine object type, then the detection process is simple and fast, but the accuracy of determining object compatibility is insufficient
Solution Approach 1:
The detection process is segmented into multiple frequency measurements (first frequency and second frequency) rather than using a single measurement. This segmentation allows the system to compare resonant current values at different frequencies, significantly improving the accuracy of determining whether an object has magnetic properties suitable for induction heating
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 method enhances the accuracy of identifying suitable objects for induction heating, reducing power wastage by ensuring only inductive objects receive heating power, thus optimizing energy usage.
Implementation Method 1
when a high-frequency power of a predetermined magnitude is applied to the working coil, an eddy current is generated in the loaded object made of a metal by using a magnetic field generated around the working coil so that the loaded object itself is heated
Implementation Method 2
an eddy current is generated in the loaded object made of a metal by using a magnetic field generated around the working coil
Implementation Method 3
a first resonant current value that is measured from the working coil in response to operation of the inverter by the switching signal having the first operation frequency and (ii) a second resonant current value that is measured from the working coil in response to operation of the inverter by the switching signal having the second operation frequency
Data Source
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AI summary
An induction heating device includes a working coil, an inverter, an inverter driving unit configured to apply a switching signal to the inverter to enable the inverter to perform a switching operation, a control unit configured to generate and apply a control signal to the inverter driving unit to cause the inverter driving unit to generate the switching signal based on the control signal, and a determination unit configured to determine a type of an object disposed on the induction heating device based on (i) a first resonant current value measured from the working coil in response to operation of the inverter by the switching signal having a first operation frequency and (ii) a second resonant current value measured from the working coil in response to operation of the inverter by the switching signal having a second operation frequency.