Wireless Charging Channel Frequency Separation for Accurate Q-Value Sensing
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Solution Overview
Problem
In wireless charging systems with multiple adjacent resonance tanks, the measurement of Q-value is inaccurate due to interference between neighboring channels, leading to unreliable detection of foreign objects.
Innovation Solution
The system employs a controller module to differentiate the operation frequency of each charging channel by at least 20% from its neighboring channels, either through a modified PWM driver signal or by reconfiguring the resonance circuit with additional inductors or capacitors, ensuring distinct resonance frequencies for accurate Q-value measurement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple charging channels operate at the same frequency, then the system can maintain simple operation and consistent performance, but Q-value measurement accuracy deteriorates due to interference between neighboring channels
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting the operating frequency of charging channels based on their operational mode. When a channel needs to perform Q-value measurement, its frequency is changed to a measurement frequency distinct from the charging frequency used by other channels. This frequency parameter adjustment eliminates interference between channels during measurement while maintaining simple operation during charging mode.
2Measurement precision
If a pulse is injected into a resonance tank to trigger free resonance for Q-value measurement, then the Q-value can be obtained through decay rate measurement, but the presence of neighboring channels causes interference and inaccurate measurement
Solution Approach 1:
The patent extracts the measurement function from the charging function by using separate frequencies. During Q-value measurement, the channel operates at a measurement frequency while other channels operate at charging frequencies. This separation extracts the measurement process from the charging process, eliminating interference from neighboring channels that would otherwise contaminate the free resonance signal.
Solution Approach 2:
The frequency acts as an intermediary that mediates between the measurement requirement and the charging operation. By introducing frequency as a distinguishing parameter, the system allows simultaneous operation of multiple channels without interference. The frequency separation creates an intermediary layer that prevents direct interaction between neighboring channel signals during measurement.
3Reliability
If all charging channels operate in charging mode simultaneously, then the system achieves high productivity, but the ability to perform accurate Q-value measurement for foreign object detection is compromised
Solution Approach 1:
The patent implements periodic action by scheduling Q-value measurements at specific intervals during charging operation. Channels periodically switch between charging mode and measurement mode, with measurements performed at frequencies distinct from charging frequencies. This periodic measurement approach ensures reliable foreign object detection while maintaining high charging productivity during the majority of operation time.
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 approach enhances the accuracy of Q-value measurement by minimizing interference, allowing precise detection of foreign objects in wireless charging systems.
Implementation Method 1
Q-value is obtained through injecting a pulse into a resonance tank of the wireless charging system, for triggering free resonance within the resonance tank, and measuring a decay rate of the free resonance signal
Implementation Method 2
The first charging module includes a first coil module and a first controller unit. The first controller unit is configured to control the first charging module to operate in a first mode and a second mode
Data Source
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AI summary
A wireless charging system includes at least a first charging module and a second charging module. The first charging module includes a first coil module and a first controller unit. The first controller unit controls the first charging module to operate in a first mode and a second mode. The second charging module includes a second coil module and a second controller unit. The second controller unit controls the second charging module to operate in the first mode and the second mode. In response to one of the first charging module and the second charging module operating in the second mode, at least one of the first controller unit and second controller unit further: sets a corresponding one of the first charging module and the second charging module to operate at a first frequency; and sets the other one of the first charging module and the second charging module to operate at a second frequency different from the first frequency.