Power transmission apparatus, power reception apparatus, control method performed by power transmission apparatus, control method performed by power reception apparatus, and storage medium
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Solution Overview
Problem
Existing wireless power transfer systems face a drop in detection accuracy when using antennas for communication during voltage or current measurement periods, leading to false positives or negatives in foreign object detection.
Innovation Solution
A power transmission apparatus equipped with a communication unit, power transmission unit, measurement unit, determination unit, and restriction unit, which performs measurements of voltage or current during power transfer cessation and uses these measurements to determine the presence of foreign objects, thereby restricting power transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If communication using the antennas used in wireless power transfer is performed during voltage measurement, then communication functionality is maintained, but the detection accuracy of foreign objects drops due to signal interference
Solution Approach 1:
The patent segments the operational timeline into distinct phases: communication periods and measurement periods. During measurement periods, communication is suspended to eliminate signal interference with voltage measurements. This temporal segmentation allows both communication and accurate measurement to function reliably without mutual interference.
Solution Approach 2:
The system implements periodic alternation between communication mode and measurement mode. The control unit schedules communication activities and measurement activities in periodic intervals, ensuring that voltage measurements for foreign object detection are performed during windows when communication signals are absent, thereby maintaining both communication functionality and measurement accuracy.
2Measurement precision
If voltage measurement is performed during power transfer cessation, then foreign object detection accuracy improves, but communication interruptions occur
Solution Approach 1:
The patent applies partial action by performing measurements during brief intervals within the power transfer cessation period, rather than continuously. The control unit schedules voltage measurements for specific time windows when power transfer is already halted, utilizing part of the available cessation time for measurement while leaving other parts for communication, thus minimizing communication interruptions while maintaining detection accuracy.
3Device complexity
If the same antenna is used for both power transfer and communication, then device complexity is reduced, but signal interference during measurement occurs
Solution Approach 1:
The system dynamically switches the antenna's functional mode between power transfer and communication based on operational requirements. The control unit manages the antenna operation to alternate between transmitting power signals and receiving communication signals, and during measurement periods, the antenna is configured solely for power transfer cessation and measurement, eliminating signal interference while maintaining a single antenna structure.
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 effectively prevents a drop in detection accuracy by ensuring accurate foreign object detection, even during periods of power transfer cessation, thereby maintaining reliable power transfer operations.
Implementation Method 1
a communication unit configured to wirelessly perform communication with a power reception apparatus using an antenna
Implementation Method 2
a power transmission unit configured to wirelessly transfer power to the power reception apparatus using the antenna
Data Source
AI summary
A power transmission apparatus 101 includes a communication unit 206 configured to wirelessly communicate with a power reception apparatus using an antenna, a power transmission unit 203 configured to wirelessly transfer power to the power reception apparatus using the antenna, a detection unit 204 configured to measure at least either a voltage or a current output from the antenna in a period where the transfer of the power is stopped and the communication by the communication unit 206 is not performed, and determine that there is an object different from the power reception apparatus based on the result of the measurement, and a control unit 201 configured to, if there is determined to be the object different from the power reception apparatus, restrict the transfer of the power.