Overvoltage Protection Device for Wireless Power Receiver
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Solution Overview
Problem
Wireless power transfer systems face challenges in protecting receivers from overvoltage events caused by frequency changes and coupling coefficient variations, which can lead to abnormal voltage stresses and potential damage to electronic devices.
Innovation Solution
An overvoltage protection device is implemented in the receiver, comprising a rectifier connected to a receiver coil, with first and second overvoltage protection apparatuses connected between the rectifier inputs and ground, and output, respectively. These apparatuses are controlled based on a comparison of the switching frequency with a predetermined threshold to activate or disable them during overvoltage events.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If overvoltage protection apparatus is activated during overvoltage events, then reliability of the receiver is improved, but device complexity increases due to frequency detection and conditional control mechanisms
Solution Approach 1:
The system continuously monitors the switching frequency and uses this feedback to dynamically control the overvoltage protection apparatus. The frequency detection unit detects the switching frequency, and the control unit compares it against a threshold to determine whether to activate the protection apparatus, creating a closed-loop feedback system that adapts to operating conditions.
Solution Approach 2:
The overvoltage protection apparatus transitions from a static always-on or always-off state to a dynamic state that adapts based on switching frequency conditions. The protection apparatus is activated only when the switching frequency exceeds a predetermined threshold, allowing the system to optimize between protection and efficiency based on real-time operating parameters.
2Productivity
If switching frequency increases during overvoltage events, then power transfer efficiency is improved, but overvoltage damage risk increases
Solution Approach 1:
The system takes preliminary protective action by detecting when switching frequency exceeds a predetermined threshold and proactively activating the overvoltage protection apparatus before severe overvoltage damage can occur. This preventive approach counteracts the harmful effects of high-frequency operation by clamping voltage or providing alternative current paths before voltage levels become dangerous.
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 protects the receiver and connected electronic devices from overvoltage damage by dynamically managing the overvoltage protection mechanisms based on switching frequency, ensuring reliable operation during abnormal voltage conditions.
Implementation Method 1
The primary side transmitter is magnetically coupled to the secondary side receiver through a magnetic coupling. The magnetic coupling may be implemented as a loosely coupled transformer having a primary side coil formed in the primary side transmitter and a secondary side coil formed in the secondary side receiver.
Implementation Method 2
The secondary side receiver is able to receive the wireless power signals through the loosely coupled transformer and convert the received wireless power signals to electrical power suitable for a load.
Data Source
AI summary
A device includes a rectifier connected to a receiver coil, a first overvoltage protection apparatus connected between inputs of the rectifier and ground, and a second overvoltage protection apparatus connected between an output of the rectifier and ground, wherein in an overvoltage event, the first overvoltage protection apparatus and the second overvoltage protection apparatus are controlled based upon a comparison between a switching frequency of the device and a predetermine frequency threshold.