Wireless Power Receiver Impedance Control for Efficient Charging
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Solution Overview
Problem
Existing wireless power transmission systems face inefficiencies due to narrow operating bandwidths and the inability to match load impedance to optimal values in real time, leading to suboptimal transmission efficiency across varying charge states.
Innovation Solution
A power receiving apparatus with a battery, protection circuit module, microcontroller module, and impedance transformation module dynamically adjusts load impedance to an optimal value using a direct-current impedance converter, such as a SEPIC or CUK converter, to optimize efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If constant-frequency voltage regulation or constant-voltage frequency regulation is used to deal with changes in load impedance, then voltage stability is improved, but charging efficiency is sacrificed
Solution Approach 1:
The patent applies dynamics by making the impedance transformation ratio adjustable rather than fixed. The impedance transformation module dynamically changes its transformation ratio according to real-time load impedance conditions, allowing the system to adapt to varying battery impedance during charging while maintaining both voltage stability and charging efficiency. This resolves the contradiction by enabling the system to be stable when needed and efficient when charging.
Solution Approach 2:
The patent changes the parameter of impedance transformation ratio dynamically. By adjusting the transformation ratio parameter based on real-time detection of load impedance, the system optimizes power transmission efficiency at different charging stages while maintaining voltage stability. This parameter change approach allows the system to overcome the efficiency loss inherent in constant-frequency or constant-voltage regulation methods.
2Adaptability or versatility
If frequency band regulation is used to match load impedance, then impedance matching is improved, but operating efficiency in narrow bandwidth bands is limited
Solution Approach 1:
The patent applies dynamics by making the impedance transformation ratio adjustable rather than fixed. The impedance transformation module dynamically changes its transformation ratio according to real-time load impedance conditions, allowing the system to adapt to varying battery impedance during charging while maintaining both voltage stability and charging efficiency. This resolves the contradiction by enabling the system to be stable when needed and efficient when charging.
Solution Approach 2:
The patent changes the parameter of impedance transformation ratio dynamically. By adjusting the transformation ratio parameter based on real-time detection of load impedance, the system optimizes power transmission efficiency at different charging stages while maintaining voltage stability. This parameter change approach allows the system to overcome the efficiency loss inherent in constant-frequency or constant-voltage regulation methods.
3Device complexity
If fixed inductance and fixed capacitance are used in the matching device, then device simplicity is improved, but optimal impedance matching cannot be achieved throughout charging process
Solution Approach 1:
The patent introduces a controlled switching element that dynamically adjusts the equivalent inductance of the matching device during operation. The control module switches between different inductor configurations based on real-time impedance detection, transforming the fixed inductance system into a dynamically adjustable one. This maintains relatively simple device structure while achieving optimal impedance matching throughout the charging process.
Solution Approach 2:
The system performs self-adjustment by detecting its own load impedance conditions and automatically switching the impedance transformation ratio accordingly. The control module monitors battery impedance changes and autonomously adjusts the matching device configuration, eliminating the need for complex external control systems while maintaining optimal efficiency throughout charging.
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 enables real-time control of load impedance, maximizing power transmission efficiency by matching impedance to optimal values, thereby enhancing overall system performance.
Implementation Method 1
a direct-current impedance converter, such as a SEPIC or CUK converter
Implementation Method 2
a wireless power transmission process is achieved through electromagnetic field coupling between a transmit antenna of the power sending apparatus and a receive antenna of the power receiving apparatus
Data Source
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AI summary
Embodiments of this application provide a power receiving apparatus, a power sending apparatus, and a power transmission method. A battery and protection circuit module is configured to obtain battery impedance. A first microcontroller module is configured to send a driving signal to an impedance transformation module based on a preset optimal value of input impedance of the impedance transformation module and the battery impedance, to adjust a duty cycle of a driving signal in the impedance transformation module, to enable the impedance transformation module to output a target voltage. The duty cycle is a ratio of high-level duration of the driving signal in one cycle to one cycle. When the impedance transformation module outputs the target voltage, the input impedance is at an optimal value of the input impedance. In this application, load impedance of the power receiving apparatus can be controlled at an optimal value in real time, to optimize the efficiency of the power transmission apparatus in the entire transmission state.