Wireless Power Transmitter Foreign Object Detection
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Solution Overview
Problem
Existing wireless power transfer systems face issues with noise caused by foreign substances, heating phenomena, interference with FM radio frequencies, and inefficient power usage, particularly when foreign objects are present in the charging region.
Innovation Solution
A wireless power transfer method that dynamically adjusts the driving voltage and transmission signals based on the presence of foreign substances, using detection signals to determine the state of the charging region and adaptively control power transmission, thereby reducing noise, heating, and standby power consumption, while minimizing interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wireless power transmission is performed using electromagnetic induction or resonance methods, then power transfer efficiency is improved, but noise and heating caused by foreign substances increase
Solution Approach 1:
The system performs foreign object detection before initiating full power transmission. By detecting the presence of foreign substances in advance using detection signals at reduced driving voltage, the system prevents noise and heating issues before they occur during normal charging operation.
Solution Approach 2:
The system dynamically adjusts the driving voltage based on detection results. When foreign substances are detected, the driving voltage is reduced to a second level, thereby reducing electromagnetic field strength and preventing excessive heating and noise while maintaining safe operation.
2Reliability
If detection signals are continuously transmitted to detect foreign objects, then safety is improved, but standby power consumption increases
Solution Approach 1:
Instead of continuous detection, the system transmits detection signals periodically at specific intervals during standby state. This periodic detection approach maintains safety monitoring capability while significantly reducing power consumption compared to continuous transmission.
Solution Approach 2:
The system changes the driving voltage parameter to a second level (lower than normal operating voltage) when transmitting detection signals. This reduced voltage minimizes power consumption during detection while still enabling effective foreign object detection through measurement of current changes.
3Speed
If high driving voltage is used for power transmission, then power transmission speed is improved, but interference with FM radio frequency increases
Solution Approach 1:
The system performs detection signal transmission at reduced voltage before initiating high-power transmission. This preliminary step identifies potential foreign objects that could cause FM interference, allowing the system to prevent high-voltage transmission that would generate harmful electromagnetic interference.
Solution Approach 2:
The driving voltage is dynamically adjusted based on detection results. When foreign substances are detected, the system maintains lower driving voltage levels that reduce electromagnetic radiation and minimize interference with FM radio frequencies while still enabling controlled power transmission when safe.
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
Effectively removes noise and heating caused by foreign substances, reduces FM radio frequency interference, and optimizes power usage by adaptively controlling the driving voltage and signal strength in response to detected foreign objects.
Implementation Method 1
The wireless power transfer method may use various wireless power transfer standards based on the electromagnetic induction method of performing charging using an electromagnetic induction principle in which a magnetic field is generated by a power transmitter coil and electricity is induced in a receiver coil due to the influence of the magnetic field.
Implementation Method 2
the wireless power transfer method may use the electromagnetic resonance method of transmitting power to a wireless power receiver located in close proximity by tuning a magnetic field generated by a transmission coil of a wireless power transmitter to a specific resonance frequency.
Implementation Method 3
when a foreign substance exists in a wireless charging region, the electromagnetic field is absorbed by the foreign substance and heating phenomenon occurs.
Data Source
AI summary
The present invention relates to wireless power transmission technology, and more particularly, to a wireless power transfer method and a device therefor. The wireless power transfer method may include operating with a first driving voltage, determining whether a ping phase is entered, determining whether the wireless power transmitter is in a first state when the ping phase is entered; and operating with a second driving voltage when the first state is determined.