Induction Heating Coil Detection via Resonant Current Pulse Analysis
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing induction heating devices face challenges in accurately detecting target objects due to noise issues during relay switching operations and difficulty in distinguishing between different working coils, leading to inefficient heating and power transfer.
Innovation Solution
The induction heating device employs a control unit that uses semiconductor switches to generate and control resonant currents, allowing for precise detection of target objects based on the number of pulses or frequency of the resonant current, thereby improving detection accuracy and reducing noise and circuit volume.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If relay switching operations are used for working coil control, then circuit switching functionality is achieved, but noise is generated during switching operations
Solution Approach 1:
The patent replaces mechanical relay switches with electronic semiconductor switches (MOSFETs or IGBTs) controlled by gate signals. This substitution eliminates the mechanical contact noise inherent in relay operations while maintaining the switching functionality required for working coil control during induction heating and wireless power transfer operations.
2Adaptability or versatility
If multiple working coils are used for zone free heating, then heating coverage is improved, but difficulty in detecting and measuring target object location increases
Solution Approach 1:
The patent divides the heating area into multiple independent zones, each with its own working coil (e.g., first working coil WC1, second working coil WC2). Each coil can be independently controlled and detected, allowing the system to identify which specific zone contains a target object and activate only that coil, thereby simplifying detection while maintaining comprehensive heating coverage.
Solution Approach 2:
The patent implements a feedback mechanism where the control unit continuously monitors the status of each working coil region and adjusts coil activation based on detected target object location. This feedback loop enables precise identification of target objects across multiple zones by responding to changes in electrical parameters when objects are present in specific coil regions.
3Productivity
If traditional detection methods are used, then target object presence is detected, but detection accuracy is reduced due to noise and inability to distinguish coil locations
Solution Approach 1:
The patent replaces traditional relay-based detection methods with electronic sensing that monitors electrical parameters (current, impedance, or resonant frequency) of each working coil independently. This electronic detection system provides higher precision in identifying target object presence and location by measuring subtle changes in coil electrical characteristics without the noise interference that plagues mechanical relay systems.
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 solution enhances target object detection accuracy, reduces noise, and optimizes energy efficiency by allowing for precise control of working coils, improving user satisfaction and space utilization while maximizing inductance changes for better wireless power transfer efficiency.
Implementation Method 1
an induction heating device (i.e., a zone free type induction heating device) in which a single target object may be simultaneously heated by a plurality of working coils, or power is simultaneously transferred to the single target object in a wireless manner through the plurality of working coils
Implementation Method 2
a first semiconductor switch that is connected to the first working coil and that is configured to turn on or off the first working coil; a second semiconductor switch that is connected to the second working coil and that is configured to turn on or off the second working coil
Implementation Method 3
detect a working coil with a target object located thereon among the first and second working coils based on the number of pulses or a frequency of the freely resonating resonant current
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
Disclosed herein is an induction heating device having improved target object detection accuracy and an induction heating system including the same. The induction heating device according to an implementation of this application includes a first working coil unit including first and second working coils connected in parallel to each other, a first inverter unit configured to apply resonant current to at least one of the first and second working coils by performing a switching operation, a first semiconductor switch connected to the first working coil to turn on or off the first working coil, a second semiconductor switch connected to the second working coil to turn on or off the second working coil, and a control unit configured to freely resonate the resonant current by controlling respective operations of the first inverter unit and the first and second semiconductor switches and detect a working coil with a target object located thereon among the first and second working coils based on the number of pulses or a frequency of the freely resonating resonant current.