Wireless Charging Receiver Capacitance Switching for Longer Coil Distance
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Solution Overview
Problem
The existing wireless charging systems face challenges in maintaining efficient power transfer over long distances due to limited adjustment ranges of operating frequencies, leading to reduced output voltage and power at the receiver circuit, especially when the transmission distance between the primary and secondary coils increases.
Innovation Solution
A wireless charging receiver circuit incorporating N capacitor-switch networks and a controller that adjusts the total capacitance values connected to the rectifier circuit by controlling controllable switch devices, allowing for the adjustment of the operating frequency of the alternating current input to the rectifier circuit, thereby compensating for increased transmission distances.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the transmission distance between the primary coil and secondary coil is increased, then the wireless charging coverage area is expanded, but the coupling efficiency is reduced and output voltage and power decrease
Solution Approach 1:
The patent changes the operating frequency parameter of the receiver circuit to compensate for power loss at increased transmission distances. By adjusting the frequency of the alternating current input to the rectifier circuit, the system maintains output power levels despite reduced coupling efficiency at larger distances between coils.
2Area of stationary object
If the transmission distance between the primary coil and secondary coil is increased, then the wireless charging coverage area is expanded, but the output voltage decreases
Solution Approach 1:
The patent adjusts the operating frequency parameter of the receiver circuit to compensate for voltage drop at increased transmission distances. By changing the frequency of the alternating current input to the rectifier circuit, the system maintains output voltage levels despite reduced coupling efficiency at larger distances between coils.
3Power
If the alternating current frequency is decreased to compensate for power loss, then the output power is maintained, but the adjustment range is limited by the WPC protocol
Solution Approach 1:
The patent introduces a dynamic frequency adjustment mechanism in the receiver circuit that operates within the WPC protocol constraints. The controller dynamically changes the operating frequency of the alternating current input to the rectifier circuit based on transmission distance and power requirements, providing adaptability within the allowed frequency range while maintaining output power.
4Stress or pressure
If the alternating current frequency is decreased to compensate for voltage loss, then the output voltage is maintained, but the adjustment range is limited by the WPC protocol
Solution Approach 1:
The patent introduces a dynamic frequency adjustment mechanism in the receiver circuit that operates within the WPC protocol constraints. The controller dynamically changes the operating frequency of the alternating current input to the rectifier circuit based on transmission distance and voltage requirements, providing adaptability within the allowed frequency range while maintaining output voltage.
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 solution enhances the output voltage and power stability of the wireless charging receiver circuit by dynamically adjusting the capacitance values in response to changes in operating frequencies, improving the efficiency of power transfer even at larger transmission distances.
Implementation Method 1
energy may be wirelessly transmitted between the wireless charging transmitter circuit 101 and the wireless charging receiver circuit 102 through magnetic induction
Implementation Method 2
The primary series resonant capacitor Cp and the primary coil Lp generate a series resonance, to generate an alternating current having a specific frequency
Implementation Method 3
The secondary coil Ls and the secondary series resonant capacitor Cs generate a series resonance, to generate an alternating current having an operating frequency
Data Source
AI summary
A wireless charging receiver circuit, a control method, and a terminal device are disclosed, to compensate for, to some extent, decreases in an output voltage and an output power of the wireless charging receiver circuit due to a great increase in a transmission distance between a secondary coil in the wireless charging receiver circuit and a primary coil in a corresponding wireless charging transmitter circuit.