Wireless Charging Rectifier Phase Control for ZVS and Output Power
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Solution Overview
Problem
Existing wireless charging systems face a challenge in maintaining high efficiency while implementing zero-voltage switching (ZVS) for controllable switching transistors, as it often leads to a decrease in output power.
Innovation Solution
A wireless charging system with a receive end compensation network and an inductance compensation module that adjusts the phase difference and phase-shift angle between bridge arms of the rectifier, allowing for zero-voltage switching while minimizing the impact on output power, by making the equivalent impedance of the rectifier purely resistive and reducing reactive power.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If zero-voltage switching is implemented for controllable switching transistors of the rectifier, then switching losses are reduced and component lifespan is prolonged, but output power of the wireless charging system significantly decreases
Solution Approach 1:
The patent applies dynamics by making the equivalent impedance of the rectifier adjustable through dynamic control of bridge arm voltage and input current. The controller dynamically adjusts the phase difference between bridge arms and the phase-shift angle between bridge arm voltage and fundamental component of input current, enabling the system to adapt impedance in real-time to achieve both ZVS and high output power
Solution Approach 2:
The patent changes physical parameters by adjusting the phase difference and phase-shift angle parameters of the rectifier. By controlling these parameters, the equivalent impedance of the rectifier is adjusted to make it purely resistive, which enables zero-voltage switching while maintaining high output power. This parameter adjustment is the core mechanism for resolving the contradiction between reducing switching losses and maintaining output power
2Loss of energy
If equivalent impedance of the rectifier is adjusted to achieve ZVS, then switching losses are reduced, but system efficiency decreases due to reactive power
Solution Approach 1:
The patent changes the impedance parameter from having reactive components to being purely resistive by adjusting the phase difference and phase-shift angle. This parameter transformation eliminates reactive power while maintaining the conditions for zero-voltage switching, thereby resolving the contradiction between reducing switching losses and maintaining system efficiency
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 efficiency of the wireless charging system by maintaining high output power while achieving ZVS for the controllable switching transistors, thereby prolonging their lifespan and reducing power consumption.
Implementation Method 1
The receive coil receives an alternating magnetic field and outputs an alternating current
Implementation Method 2
implementing a zero-voltage switching (ZVS) effect for the controllable switching transistors can greatly reduce switching losses
Data Source
AI summary
Example wireless charging systems and methods are disclosed. One example system includes a receive end and a transmit end. The receive end includes a receive coil, a receive end compensation circuit, a rectifier, and a controller. The controller adjusts a phase difference between a first bridge arm and a second bridge arm of the rectifier, and adjusts a phase-shift angle between a bridge arm voltage of the rectifier and a fundamental component of an input current of the rectifier, so that zero-voltage switching is implemented for controllable switching transistors of the rectifier. An inductance compensation module may weaken a capacitive part of the equivalent impedance, and reduce reactive power of the wireless charging system.