Wireless Power Transfer Efficiency via Receiver Impedance Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional Transcutaneous Energy Transfer (TET) systems for implantable medical devices face inefficiencies in power transfer, particularly for higher power devices, due to heat losses and limited acceptable temperature rise in tissue, requiring precise alignment and orientation of coils and additional mechanisms to maintain efficient energy delivery.
Innovation Solution
A wireless power transfer system that includes a transmitter and receiver with a controller to determine Thevenin equivalent impedance and source voltage, allowing the receiver to adjust the ideal source voltage for efficient power transfer, accommodating looser coil coupling and minimizing heat loss by optimizing energy balance between voltage and current.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If conventional TET systems use fixed coil positioning and alignment mechanisms, then power transfer can be maintained, but device complexity increases and ease of operation decreases
Solution Approach 1:
The patent implements dynamic impedance matching that automatically adjusts to changing coupling conditions between transmit and receive coils. The system continuously monitors and adapts the matching network parameters, eliminating the need for mechanical alignment mechanisms while maintaining optimal power transfer efficiency across varying coil positions and orientations.
Solution Approach 2:
The system employs feedback control through impedance sensing that detects changes in coupling conditions and automatically adjusts the impedance matching network. This closed-loop control maintains maximum power transfer efficiency without requiring precise mechanical alignment or complex positioning mechanisms.
2Power
If higher power is transmitted to meet device requirements, then power delivery improves, but heat loss and tissue temperature increase
Solution Approach 1:
The patent converts the harmful effect of heat loss into a useful diagnostic tool by monitoring impedance changes that indicate coupling conditions. This allows the system to optimize power transfer efficiency, delivering higher power when needed while minimizing waste heat through improved matching, thus controlling tissue temperature rise.
Solution Approach 2:
The system dynamically changes impedance parameters to optimize power transfer efficiency at different power levels. By adjusting the matching network parameters in real-time, the system maximizes efficient power delivery while minimizing resistive losses that would otherwise generate harmful heat in the tissue.
3Power
If impedance matching is optimized for maximum power transfer, then power delivery improves, but system complexity increases
Solution Approach 1:
The patent implements a self-adjusting impedance matching system that automatically adapts to changing conditions without external control. The matching network uses inherent feedback from the coupled coils to self-tune, eliminating the need for complex control circuits or manual adjustment mechanisms while maintaining optimal power transfer.
Solution Approach 2:
The system employs variable impedance elements that can be adjusted to match different loading conditions and coupling states. These parameter changes are achieved through simple switching networks or variable components that provide adaptive impedance matching without requiring complex control systems.
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 enhances power transfer efficiency, reduces heat loss, and allows for more flexible positioning of coils, improving the ability to power higher power devices while maintaining safe tissue temperature, thus addressing the limitations of conventional TET systems.
Implementation Method 1
A conventional TET system is implemented with a transmitting coil and a receiving coil for transmitting energy across the skin layer
Implementation Method 2
a receiver inductively coupled to the transmitter, the receiver configured to receive the wireless power from the transmitter
Implementation Method 3
Resonant power transfer systems having efficiency optimization based on receiver impedance
Data Source
AI summary
The present disclosure provides systems and methods for controlling wireless power transfer systems. A wireless power transfer system includes a transmitter driven by a power source and a transmit controller, wherein the transmitter is configured to control delivery of wireless power, and a receiver inductively coupled to the transmitter, the receiver configured to receive the wireless power from the transmitter and deliver the received wireless power to a load. The receiver includes receiver electronics configured to determine a Thevenin equivalent impedance of the wireless power transfer system, determine a Thevenin equivalent source voltage of the wireless power transfer system, and control, based on the determined Thevenin equivalent impedance and the determined Thevenin equivalent source voltage, an ideal source voltage of the receiver to vary the amount of the wireless power transferred from the transmitter to the receiver.