Wireless power transmission apparatus for induction heating and control method thereof
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless power transmission devices for kitchen appliances face challenges in detecting foreign objects between the reception and working coils, leading to reduced efficiency and safety concerns due to high power consumption and potential ignition risks, especially when the transmission power is high.
Innovation Solution
A wireless power transmission apparatus that uses a controller to determine the presence of foreign objects by analyzing differences in input and resonance currents across varying frequencies during a preparation period, integrating these values to decide on alarm-based removal and ensuring safe power transfer without the need for additional sensors or communication devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wireless power transmission is performed at high power levels, then power transmission efficiency is improved, but the risk of ignition and foreign object heating increases
Solution Approach 1:
The system performs foreign object detection during a preparation period before actual wireless power transmission begins. By detecting foreign objects in advance using electromagnetic induction at reduced power levels, the system can prevent ignition risks while maintaining the ability to transmit high power efficiently when safe
Solution Approach 2:
The system continuously monitors electromagnetic field characteristics and power consumption patterns during wireless power transmission. When foreign objects are detected or abnormal heating is identified, the system provides feedback to adjust or terminate power transmission, thereby managing ignition risks while optimizing transmission efficiency
2Reliability
If foreign object detection is performed during wireless power transmission, then safety is improved, but transmission efficiency is reduced due to power consumption
Solution Approach 1:
Foreign object detection is performed during a preparation period before full power transmission begins. This preliminary detection uses minimal power while identifying foreign objects, allowing the system to proceed with high-efficiency power transmission when safe without continuous detection overhead
Solution Approach 2:
The system performs foreign object detection periodically rather than continuously during power transmission. Detection occurs at specific intervals or phases, reducing overall power consumption while maintaining adequate safety monitoring throughout the transmission process
3Device complexity
If a single working coil is used for both induction heating and wireless power transmission, then device complexity is reduced, but mode switching and foreign object detection become more difficult
Solution Approach 1:
The single working coil is designed to perform multiple functions: induction heating, wireless power transmission, and foreign object detection. By optimizing the coil's electromagnetic characteristics and using software-controlled frequency/power adjustment, the system achieves multi-functionality without additional hardware complexity
Solution Approach 2:
The system switches between induction heating and wireless power transmission modes by changing operational parameters such as frequency, power level, and detection thresholds. This parameter-based mode switching allows a single coil to adapt to different functions without physical reconfiguration, maintaining simplicity while achieving versatility
4Measurement precision
If foreign object detection sensitivity is increased to detect minute variations, then detection accuracy is improved, but false detection increases at high transmission power
Solution Approach 1:
The system performs foreign object detection during a preparation period before high-power transmission begins. During this low-power phase, the system can detect minute variations in electromagnetic field characteristics with high sensitivity without the interference and noise generated by high transmission power, thereby avoiding false detections
Solution Approach 2:
The system applies detection sensitivity that would be excessive during high-power transmission by performing detection at reduced power levels during the preparation period. This partial action approach allows high sensitivity detection without the adverse effects of high power interference, achieving accurate foreign object identification
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
Enhances the accuracy and safety of wireless power transfer by effectively detecting and removing foreign objects, reducing the risk of ignition and improving transmission efficiency, even at high power levels, by using a single working coil for both induction heating and wireless power transmission modes.
Implementation Method 1
a general electron induction heating device allows high-frequency current to flow in a working coil or heating coil installed therein. When the high-frequency current flows in the working coil or the heating coil, a strong line of magnetic force is generated. The line of magnetic force generated in the working coil or the heating coil forms eddy current while being transmitted through a cooking tool. Thus, as eddy current flows in a cooking tool, heat is generated to heat a container itself
Implementation Method 2
The line of magnetic force generated in the working coil or the heating coil forms eddy current while being transmitted through a cooking tool. Thus, as eddy current flows in a cooking tool, heat is generated
Implementation Method 3
when alternating current (AC) flows in a transmission coil, a battery is charged by forming a magnetic field around a transmission coil, allowing AC to flow in a reception coil due to influence of the magnetic field
Data Source
Figure 1
Figure 2~3
Figure 4~5
AI summary
A wireless power transmission apparatus for induction heating includes a working coil configured to change a mode depending on selection of a user, to vary an operation frequency depending on the mode and to induction-heat a target object, or to wirelessly transmit power to the target object, an inverter that is turned on and off depending on the operation frequency and configured to generate the power, and a controller configured to determine whether a foreign object is positioned on the working coil over a plurality of modes in a preparation period prior to wireless power transfer (WPT) when the user selects a wireless power transmission mode. Thus, a multi-functional wireless power transmission device using one working coil detects whether a foreign object is present, compensates for this, and performs WPT in a wireless power transmission mode while selectively driving a wireless power transmission mode or an induction heating mode.