Active Rectifier for Wireless EV Charging
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Solution Overview
Problem
Conventional wireless power transfer systems for high-voltage battery charging in electric vehicles face issues with communication delays and failures, which can stop operations or damage components, and require additional converters that increase system size and cost.
Innovation Solution
An active rectifier is used within the vehicle assembly to control the output of the wireless power transfer system directly, eliminating the need for wireless communications and additional converters by employing a bridge circuit with switching circuits and a controller that adjusts based on battery charging status and induced coil voltages or currents.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If wireless communication is used for controlling the wireless power transfer system, then the system can operate remotely, but communication delays and failures can stop operations or damage components
Solution Approach 1:
The patent introduces a local controller as an intermediary device within the vehicle assembly that receives and processes control signals locally, eliminating the need for continuous wireless communication during power transfer. This mediator ensures reliable operation by maintaining control functions even when wireless communication is delayed or failed.
2Manufacturing precision
If additional converters are added to control the wireless power transfer output, then the charging control precision is improved, but the system size and cost increase
Solution Approach 1:
The patent makes the rectifier circuit perform multiple functions: it not only converts AC to DC for battery charging but also actively controls the wireless power transfer output by adjusting its switching duty cycle. This multi-functional approach eliminates the need for separate control converters, reducing system size and cost while maintaining precise charging control.
Solution Approach 2:
The patent merges the power conversion function and the power control function into a single rectifier circuit. By combining these functions, the system avoids adding separate converters, thereby reducing device complexity and cost while achieving precise charging control through the rectifier's duty cycle adjustment.
3Manufacturing precision
If additional converters are added to control the wireless power transfer output, then the charging control precision is improved, but the manufacturing cost increases
Solution Approach 1:
The rectifier circuit is designed to perform both power conversion and active power control functions, eliminating the need for additional expensive control converters. This multi-functional design reduces component count and manufacturing cost while maintaining precise charging control capability.
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 prevents operation stops and component damage due to communication failures and reduces system size and cost by allowing direct control of the wireless power transfer, ensuring efficient and reliable high-voltage battery charging.
Implementation Method 1
a secondary coil which is equipped in a vehicle, and couples inductively with an external primary coil
Implementation Method 2
a rectifier including a first rectifying circuit, a second rectifying circuit, a first switching circuit, and a second switching circuit which are arranged in a form of a bridge circuit between the secondary coil and the battery
Data Source
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AI summary
An active rectifier for a wireless power transfer system includes: a first rectifying circuit; a second rectifying circuit; a first switching circuit and a second switching circuit. The first rectifying circuit, the second rectifying circuit, the first switching circuit, and the second switching circuit are arranged in a form of a bridge circuit between a secondary coil of a vehicle and a battery of the vehicle, and the active rectifier controls the first and second switching circuits according to a charging status of the battery or an output status of the wireless power transfer system in order to change or maintain a charging power to the battery.