Wireless Power Transmitter Feedback Control for Position Stability
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Solution Overview
Problem
Existing wireless energy transmission systems using inductive coupling are prone to instability and potential physical damage due to frequent changes in the relative position of the receiver with respect to the transmitter, particularly in mobile environments, leading to overstressing of components and incomplete battery charging.
Innovation Solution
A transmitter with a resonant transformer and bridge circuit that utilizes feedback from electrical operating parameters to control the bridge circuit, adapting the drive frequency based on changes in the geometric arrangement between the coils, thereby reducing the impact of positional changes and ensuring stable operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If the resonant frequency is adjusted frequently to maintain optimal energy transmission, then the energy transmission efficiency is improved, but the stability and reliability of the power supply unit deteriorates due to overstressing of components
Solution Approach 1:
The patent implements a feedback mechanism that continuously monitors the resonant frequency and automatically adjusts the excitation frequency of the bridge circuit to match changes in the resonant frequency caused by receiver position variations. This closed-loop control maintains optimal energy transmission efficiency while preventing excessive frequency adjustments by only changing frequency when actually needed, thus protecting the power supply unit from overstressing
Solution Approach 2:
The system dynamically adapts the excitation frequency based on real-time conditions. The bridge circuit is designed to follow the resonant frequency of the transformer, which varies with receiver position. This dynamic adjustment ensures continuous optimal performance without requiring manual intervention or excessive frequent changes that would stress the components
2Adaptability or versatility
If the excitation frequency is changed frequently to track resonant frequency changes, then the adaptability to position changes is improved, but the control stability deteriorates leading to potential physical damage
Solution Approach 1:
A feedback loop monitors the resonant frequency and triggers frequency changes only when necessary. The system detects when the resonant frequency has shifted due to receiver movement and then adjusts the excitation frequency accordingly, rather than continuously or frequently changing it. This selective adjustment maintains control stability while preserving adaptability to position changes
Solution Approach 2:
The system uses the resonant transformer itself as a sensor to detect position changes through its resonant frequency characteristics. This self-service approach eliminates the need for separate position sensors and allows the system to automatically adapt to position changes while maintaining stable control through intelligent frequency adjustment
3Reliability
If a safety circuit is provided to limit frequent control influences, then the reliability is improved, but the energy transmission efficiency deteriorates due to premature termination of charging
Solution Approach 1:
The system dynamically adjusts the excitation frequency to follow the resonant frequency, which changes with receiver position. This dynamic tracking ensures that energy transmission remains efficient throughout the charging process, even when the receiver moves. The safety circuit is designed with intelligent thresholds that distinguish between normal resonant frequency variations and actual dangerous conditions, allowing charging to continue safely without premature termination
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 provides position-independent wireless energy transmission, reducing the frequency and severity of disturbances to the transmitter components, allowing for safe and efficient charging even in mobile environments.
Implementation Method 1
The transmitting coil is made to oscillate electrically so that an alternating electromagnetic field is set up in its area of influence
Implementation Method 2
The power supply unit is usually built on the basis of a resonant transformer, which is excited by means of a bridge circuit and includes a resonant capacitance in addition to the transmission coil. The periodic excitation results in an electrical oscillation that ideally corresponds to the resonant frequency of the resonant transformer
Implementation Method 3
The two coils are inductively coupled to one another for energy transmission by arranging the small electrical device on the power pack in such a way that the receiving coil comes to rest in an electromagnetic area of influence of the transmitting coil
Data Source
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AI summary
The invention relates to a transmitter for wirelessly transmitting power, comprising a resonant transformer with a transmission coil and a resonant capacitance in addition to a bridge circuit for exciting the resonant transformer. Said transmitter also comprises a back coupling element for controlling the bridge circuit in accordance with a modification of a geometric arrangement of a receiver with respect to the transmitter coil.