Wireless Charging Coil Saturation Detection and Current Adjustment
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Solution Overview
Problem
Wireless charging systems face inefficiencies due to magnetic saturation in coils and the inability to distinguish between power losses caused by foreign objects and saturation, leading to potential overheating and suboptimal charging.
Innovation Solution
A method to differentiate between power losses due to foreign objects and magnetic saturation by adjusting the transmission coil current, reducing it incrementally until optimal power transfer is achieved without saturation, ensuring safe and efficient charging.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If transmission coil current is increased to improve charging speed, then productivity is improved, but magnetic saturation occurs causing energy transfer efficiency to deteriorate
Solution Approach 1:
The system continuously monitors power loss during wireless charging and uses this feedback to detect magnetic saturation. When saturation is detected through power loss analysis, the system automatically adjusts the transmission coil current to maintain optimal charging efficiency without excessive energy loss.
Solution Approach 2:
The system dynamically changes the transmission coil current parameter based on detected power loss levels. By adjusting this parameter in response to saturation conditions, the system optimizes both charging speed and energy transfer efficiency, preventing the contradiction between high current and saturation losses.
2Reliability
If foreign object detection is implemented to ensure safety, then reliability is improved, but the ability to distinguish between foreign objects and saturation is lost causing false positives
Solution Approach 1:
The foreign object detection process is segmented into multiple stages: initial power loss detection, saturation determination through current adjustment, and final foreign object identification. This segmentation allows the system to distinguish between saturation-induced power loss and foreign object-induced power loss with higher precision.
Solution Approach 2:
The system performs preliminary saturation determination by adjusting transmission coil current before finalizing foreign object detection. This preliminary action eliminates saturation as a confounding factor, allowing more accurate foreign object detection without false positives.
3Loss of energy
If transmission coil current is reduced to avoid magnetic saturation, then energy transfer efficiency is improved, but charging speed deteriorates
Solution Approach 1:
The system dynamically adjusts transmission coil current based on real-time power loss monitoring and saturation detection. Rather than using a fixed current level, the system optimizes current dynamically to achieve both high energy transfer efficiency and acceptable charging speed, resolving the contradiction between these two parameters.
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 approach optimizes wireless charging by preventing overheating from foreign objects while maintaining efficient energy transfer, even when coil characteristics are unknown, ensuring compliance with foreign object detection standards.
Implementation Method 1
a coil in the first device may be electromagnetically energized. The electromagnetic energy from the first device may, for example, energize a coil in the second device
Implementation Method 2
The electromagnetic energy from the first device may, for example, energize a coil in the second device, thus inducing an electrical current in the coil in the second device
Implementation Method 3
magnetic saturation in either the wireless charger or the device, which reduces the efficiency of energy transfer
Data Source
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AI summary
A method is provided for optimizing wireless charging of a mobile device by a wireless charger. The method comprises determining whether magnetic saturation occurred in at least one of the mobile device and the wireless charger during a first wireless transmission of power from the wireless charger to the mobile device; and, when magnetic saturation is determined to have occurred, successively reducing transmit power in the wireless charger until reaching an operating wireless transmit power, wherein neither the mobile device nor the wireless charger is in magnetic saturation at the operating wireless transmit power.