Wireless Power Coil Initialization for Foreign Object Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wireless power transmission systems face challenges in detecting foreign objects, which can impede power transmission and potentially cause damage or overheating due to the presence of metallic objects between the transmitter and receiver.
Innovation Solution
A method and apparatus that utilize a primary and secondary core block system with magnetic induction or resonance to detect foreign objects by measuring initial transmission power and voltage, allowing for foreign object detection before power transmission begins, thereby preventing interference and reducing the risk of overheating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If wireless power transmission is performed without foreign object detection, then power transmission efficiency is maintained, but safety hazards such as overheating and damage to foreign objects occur
Solution Approach 1:
The system performs foreign object detection during an initialization phase before actual power transmission begins. By measuring impedance or voltage characteristics of the primary coil before energizing the system, the controller can identify foreign objects and prevent power transmission that would cause safety hazards, thus resolving the contradiction between safety and transmission efficiency.
2Reliability
If foreign object detection is performed during power transmission, then safety is improved, but transmission time and system complexity increase
Solution Approach 1:
The detection function is executed during the initialization phase before power transmission starts, not during active transmission. This timing strategy allows comprehensive safety checks to be performed without adding to the actual power transmission time, thus improving detection accuracy while minimizing time loss.
Solution Approach 2:
The same primary coil and control circuitry used for power transmission are also utilized for foreign object detection during initialization. This multi-functional approach allows detection capabilities to be integrated without requiring separate dedicated detection hardware, thereby reducing system complexity while maintaining detection accuracy.
3Reliability
If contact-type electrical interface is used for charging, then charging reliability is achieved, but workspace occupation and aesthetic issues arise due to cables
Solution Approach 1:
The patent replaces the mechanical cable-based contact interface with a wireless electromagnetic field-based power transmission system. The primary coil generates an electromagnetic field that induces current in the secondary coil of the receiving device, eliminating the need for physical cables and contacts, thus reducing workspace occupation while maintaining charging reliability through controlled electromagnetic coupling.
4Device complexity
If wireless power transmission is implemented without foreign object detection capability, then device complexity is reduced, but harmful effects from foreign objects such as overheating and detonation occur
Solution Approach 1:
The system performs impedance measurement or voltage sensing during the initialization phase to detect foreign objects before power transmission begins. This preliminary detection uses existing circuit components without adding complex dedicated detection hardware, thereby maintaining relatively simple system architecture while preventing harmful effects from foreign objects by avoiding power transmission when foreign objects are present.
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 effectively detects foreign objects before power transmission, reducing the risk of overheating and ensuring safe and efficient wireless power transfer by separating the detection phase from the power transmission phase.
Implementation Method 1
a primary core block coupled with a secondary core block installed in a wireless power receiving apparatus, where the primary core block transmits wireless power to the wireless power receiving apparatus through magnetic induction or magnetic resonance
Implementation Method 2
a primary core block coupled with a secondary core block installed in a wireless power receiving apparatus, where the primary core block transmits wireless power to the wireless power receiving apparatus through magnetic induction or magnetic resonance
Implementation Method 3
A wireless power transmitting apparatus which detects one or more foreign objects comprises a primary core block coupled with a secondary core block installed in a wireless power receiving apparatus
Data Source
AI summary
The present disclosure provides an apparatus and method for detecting a foreign object in a wireless power transmitting system. The wireless power transmitting apparatus measures an initial transmission power transmitted from the primary core block and performs foreign object detection on the basis of the initial transmission power, once it is found that an initial voltage of an output terminal of the wireless power receiving apparatus connected to an external load is within the range of a reference voltage. By performing foreign object detection while a wireless power receiving apparatus is in an initial setting completion state, before the output of the wireless power receiving apparatus is turned on, delay in detecting foreign objects may be reduced, and a risk due to heating of a foreign object may be avoided.