Wireless Power Receiver Sequencing for Accurate Foreign Object Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The accuracy of foreign object detection in wireless power transmission systems can deteriorate due to changes in output voltage to the load of a power receiving apparatus, affecting the reliability of detecting objects different from the power receiving apparatus based on power loss methods.
Innovation Solution
A power receiving apparatus performs initial detection processing by measuring voltage or current values at multiple time points during restricted power transmission and transmits data to the power transmission apparatus, which then uses this data for secondary detection processing. The power receiving apparatus adjusts its output voltage only after data transmission, ensuring it is not used in subsequent detection processing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the power receiving apparatus changes output voltage to the load, then the power transmission efficiency is improved, but the accuracy of foreign object detection based on power loss deteriorates
Solution Approach 1:
The system performs first detection processing using voltage or current values at multiple time points during restricted power transmission before changing the output voltage. This preliminary detection establishes a baseline foreign object detection result that is not affected by subsequent voltage changes, allowing the system to maintain detection accuracy while still enabling efficient power transmission at adjusted voltage levels.
Solution Approach 2:
The foreign object detection process is divided into two separate stages: first detection processing based on voltage or current measurements during restricted transmission, and second detection processing based on power loss calculations. By segmenting the detection into these independent stages, the system can perform voltage adjustments between stages without compromising the accuracy of either detection method.
2Reliability
If the power receiving apparatus transmits received power data for second detection processing, then the foreign object detection capability is enhanced, but the system complexity increases
Solution Approach 1:
The system combines two detection approaches by having the power receiving apparatus transmit received power data that the power transmission apparatus uses for second detection processing based on power loss. This merging of detection capabilities allows both the receiving and transmission apparatus to contribute to foreign object detection, enhancing overall reliability without requiring completely separate detection systems.
Data Source
AI summary
A power receiving apparatus wirelessly receives power from a power transmission apparatus that performs first detection processing of detecting a foreign object based on values of voltages or currents at at least two time points in a predetermined period during which power transmission is restricted, transmits, to the power transmission apparatus, data indicating received power that is to be used in second detection processing of detecting a foreign object based on power loss in accordance with a result of the first detection processing, changes an output voltage to be output to a load, and, in a case where the output voltage is changed after the data is transmitted, controls the data not to be used in the second detection processing.