Wireless Power Receiver Voltage Regulation at Zero Crossings
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Solution Overview
Problem
Existing wireless charging systems face challenges in efficiently regulating rectified voltage during load changes and power transmission, leading to conduction losses and voltage spikes, which restrict the rate of change of rectified power levels.
Innovation Solution
Incorporating a voltage regulator circuitry within the wireless power receiving device that includes a zero crossing detection circuit, pulse generation circuit, integration circuit, difference circuit, and proportional integration controller to override the rectifier controller and activate pull-down switches when the voltage across the capacitor is zero, allowing for fast voltage regulation independent of the power transmitting device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If traditional rectifier control is used in wireless charging systems, then the system structure is simple, but voltage regulation is slow and causes conduction losses
Solution Approach 1:
The voltage regulator circuitry is segmented into distinct functional modules: zero crossing detection circuit, pulse generation circuit, integration circuit, difference circuit, and proportional integration controller. Each module performs a specific function in the voltage regulation process, allowing for optimized control while maintaining manageable system complexity.
Solution Approach 2:
The system implements feedback control by continuously monitoring the rectifier output voltage and capacitor voltage, comparing them against reference values through the difference circuit, and adjusting the rectifier switches accordingly. This closed-loop feedback mechanism enables fast voltage regulation and reduces conduction losses by optimizing the switching timing.
2Speed
If traditional rectifier control is used, then the device complexity is low, but voltage regulation speed is slow
Solution Approach 1:
The zero crossing detection circuit detects when the capacitor voltage reaches zero before the rectifier switches would normally be activated. This preliminary detection allows the system to prepare and execute switch activation at the optimal moment, achieving fast voltage regulation without excessive complexity.
Solution Approach 2:
The voltage regulator circuitry dynamically adjusts the timing of rectifier switch activation based on real-time voltage conditions. By making the switching timing dynamic rather than fixed, the system achieves fast voltage regulation response while adapting to varying load conditions.
3Productivity
If fast voltage regulation is implemented, then conduction losses are reduced, but the system complexity increases
Solution Approach 1:
The voltage regulator circuitry is integrated within the existing wireless power receiving device, merging the regulation function with the rectifier controller. This integration allows fast voltage regulation to improve power transmission efficiency while sharing common components and reducing overall system complexity.
Solution Approach 2:
The voltage regulator circuitry autonomously monitors voltage conditions and adjusts rectifier switch timing without requiring external intervention. This self-service capability enables fast voltage regulation and improved efficiency while minimizing the need for additional control systems.
4Object-affected harmful factors
If voltage regulation is overridden at zero voltage points, then voltage spikes are reduced, but control complexity increases
Solution Approach 1:
The zero crossing detection circuit identifies when the capacitor voltage reaches zero before voltage spikes can occur. By activating or deactivating rectifier switches at these critical zero-voltage moments, the system preemptively prevents voltage spikes from developing, reducing harmful effects while adding only minimal control complexity.
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 enables faster and more efficient voltage regulation, reducing conduction losses and voltage spikes, allowing for higher rates of load changes and increased power capability, thereby improving the reliability and efficiency of wireless charging systems.
Implementation Method 1
a wireless charging coil having a first coil terminal and a second coil terminal... uses an inverter to supply alternating-current signals at a carrier frequency to a coil and thereby transmit wireless power signals
Implementation Method 2
The wireless power receiving device has a coil and rectifier circuitry that uses electromagnetic flux produced by the transmitter to generate direct-current power
Data Source
AI summary
A wireless charging system having a power transmitting device may wirelessly transfer power to a power receiving device. The power receiving device may include a voltage regulator that operates independently from the power transmitting device. The voltage regulator may output a rectified voltage and may activate pull-down rectifier switches during zero voltage crossings to boost the rectified voltage. The power receiving device may send control error packets to the power transmitting device to direct the power transmitting device to adjust the transmit power level.