Wireless Power Receiver Impedance Control
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Solution Overview
Problem
The charging efficiency of a wireless power receiver depends on impedance matching, which is typically achieved using a matching circuit, increasing the weight and volume of the device.
Innovation Solution
A wireless power receiver that maintains impedance at a predetermined value adaptively without using a matching circuit, employing a controller to adjust the impedance by measuring current and voltage at the input end of the battery and adjusting the voltage at the output end of the DC/DC converter to maintain impedance matching with the transmitter.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a matching circuit is used to achieve impedance matching, then charging efficiency is improved, but device weight and volume increase
Solution Approach 1:
The patent extracts and removes the matching circuit from the wireless power receiver system. Instead of using a separate matching circuit component, the invention implements impedance matching functionality through control of the DC/DC converter, thereby eliminating the matching circuit and reducing device weight and volume while maintaining charging efficiency
Solution Approach 2:
The DC/DC converter is given multiple functions: it not only performs voltage conversion but also implements impedance matching by adjusting its duty cycle. This multi-functionality eliminates the need for a separate matching circuit, reducing the number of components and overall device weight
2Productivity
If a matching circuit is used to achieve impedance matching, then charging efficiency is improved, but device volume increases
Solution Approach 1:
The matching circuit is extracted and removed from the system. The impedance matching function is integrated into the DC/DC converter control, eliminating the need for separate matching circuit components and thereby reducing device volume
Solution Approach 2:
The impedance matching function is merged with the DC/DC converter control functionality. By combining these functions into a single control mechanism, the patent reduces the number of separate components and overall device volume
3Productivity
If a matching circuit is used to achieve impedance matching, then charging efficiency is improved, but installation area is reduced
Solution Approach 1:
The matching circuit is removed from the system, eliminating the space it would occupy on the charging pad. The DC/DC converter-based impedance matching requires no additional physical space, thereby increasing available installation area
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 allows for high charging efficiency without the need for a matching circuit, reducing the weight and volume of the device while securing a larger installation area.
Implementation Method 1
a resonant circuit configured to receive the electromagnetic waves and output AC power
Implementation Method 2
a rectifier configured to convert the AC power into DC power
Implementation Method 3
a DC/DC converter configured to convert the rectified DC power
Data Source
Figure 1~2
Figure 3a
Figure 3b~4a
AI summary
A wireless power receiver and a method for controlling the wireless power receiver are provided. The wireless power receiver includes a resonant circuit configured to receiving electromagnetic waves from a wireless power transmitter and output alternate current (AC) power, a rectifier configured to rectify the AC power received from the resonant circuit into direct current (DC) power, a DC/DC converter configured to convert the rectified DC power received from the rectifier and output the converted DC power, a battery, a charger configured to charge the battery with the converted DC power, and a controller configured to, upon detection of an event indicating a change in impedance at an output end of the DC/DC converter, control the impedance at the output end of the DC/DC converter to be kept constant by adjusting voltage at the output end of the DC/DC converter.