Wireless Power Transmission Frequency Control for Safety
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Solution Overview
Problem
Existing wireless power transmission systems using resonance-type magnetic coupling face challenges in maintaining high transmission efficiency while ensuring safety, as the frequency providing maximum efficiency may not be safe due to high magnetic field intensity, which can cause heat generation from metallic foreign matters.
Innovation Solution
A power transmitting device that adjusts its transmission frequency based on detected voltage values to set the frequency between a local minimum and a local maximum value, reducing magnetic field intensity and ensuring safe and efficient power transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the frequency providing maximum transmission efficiency is used, then transmission efficiency is improved, but magnetic field intensity increases causing safety issues
Solution Approach 1:
The patent changes the operating frequency parameter from the maximum efficiency frequency to a frequency within a specific range that provides both high transmission efficiency and reduced magnetic field intensity. The control circuit adjusts the frequency based on the relationship between frequency, transmission efficiency, and magnetic field intensity characteristics.
Solution Approach 2:
The patent uses feedback by measuring the actual transmission efficiency and magnetic field intensity at different frequencies, then using this information to determine the optimal operating frequency that satisfies both efficiency and safety requirements. The system continuously monitors and adjusts based on real-time conditions.
2Object-affected harmful factors
If frequency adjustment is implemented to reduce magnetic field intensity, then safety is improved, but transmission efficiency may deteriorate
Solution Approach 1:
The patent identifies and operates within a specific frequency range where both transmission efficiency remains high and magnetic field intensity is reduced. This involves characterizing the system's frequency-response characteristics and selecting operating points that satisfy both criteria simultaneously rather than treating them as strictly opposing goals.
3Productivity
If resonance-type magnetic coupling is used, then transmission efficiency is maintained even with position deviation, but magnetic field intensity increases causing heat generation from metallic foreign matters
Solution Approach 1:
The patent adjusts the operating frequency parameter to reduce magnetic field intensity while maintaining resonance coupling benefits. By operating at a frequency that provides adequate coupling without excessive field strength, the system maintains transmission efficiency while preventing harmful heat generation in metallic objects.
Solution Approach 2:
The system monitors transmission efficiency and magnetic field levels to detect conditions that may lead to excessive heating, then adjusts the operating frequency in real-time to maintain safe operation while preserving efficient power transfer.
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
The solution allows for safe and highly-efficient power transmission by reducing magnetic field intensity, preventing heat generation from metallic foreign matters and maintaining transmission efficiency.
Implementation Method 1
The wireless power transmission system transmits electric power from a power transmitting device to a power receiving device in a noncontact manner through electromagnetic induction between a power transmitting antenna of the power transmitting device and a power receiving antenna of the power receiving device
Implementation Method 2
a wireless power transmission system using the power transmitting antenna and the power receiving antenna of resonance type is also called a resonant magnetic coupling system, and it can maintain high transmission efficiency even when positions of the power transmitting antenna and the power receiving antenna are deviated from each other
Data Source
AI summary
A power transmitting device includes a power transmitting circuit that converts second DC power input from a DC power supply to AC power, a power transmitting antenna and a control circuit that receives a voltage value of the first DC power from the power receiving device. The control circuit changes a frequency of the AC power that is transmitted to the power receiving antenna, detects, from the received voltage values, a first frequency corresponding to a local minimum value of the voltage values and a second frequency corresponding to the voltage value that takes a local maximum value at a frequency higher than the first frequency, and sets the frequency of the AC power transmitted to the power receiving antenna to a frequency between the first frequency and the second frequency.