Wireless Charging Inverter Phase Modulation for EMI Reduction
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Solution Overview
Problem
Existing wireless charging technologies face challenges in reducing electromagnetic interference (EMI) during power transmission, particularly during low-power operations, leading to potential disconnection issues.
Innovation Solution
A power control method for wireless charging that adjusts the frequency and phase of the control signal to optimize power transmission, using a control circuit to manage the power transmission circuit and communication with external devices to reduce EMI and prevent disconnection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If wireless power transmission is performed at high power levels, then charging speed is improved, but electromagnetic interference increases
Solution Approach 1:
The patent implements dynamic power adjustment by continuously monitoring EMI levels and adapting the power transmission level accordingly. The system transitions from static high-power charging to dynamic power modulation, reducing power levels when EMI exceeds thresholds while maintaining optimal charging speed when EMI is acceptable.
Solution Approach 2:
The system changes the power transmission parameter based on EMI conditions. By monitoring electromagnetic interference levels and adjusting the power transmission parameter dynamically, the system resolves the contradiction between maintaining high charging speed and reducing EMI impact.
2Object-affected harmful factors
If power transmission level is reduced for low-power devices, then EMI is reduced, but power disconnection occurs
Solution Approach 1:
The patent implements a feedback mechanism that continuously monitors both EMI levels and power transmission status. When EMI is high, the system reduces power but receives feedback about connection stability. If disconnection is detected, the feedback loop adjusts the power level to maintain connection, thus resolving the contradiction between EMI reduction and connection stability.
Solution Approach 2:
The system takes preliminary anti-action by monitoring power transmission stability before complete disconnection occurs. When signs of potential disconnection are detected during low-power transmission, the system preemptively adjusts power levels to prevent disconnection, countering the harmful effect before it fully manifests.
3Object-affected harmful factors
If frequency and phase adjustment is implemented to reduce EMI, then electromagnetic interference is minimized, but control system complexity increases
Solution Approach 1:
The patent applies partial frequency and phase adjustment only when EMI thresholds are exceeded, rather than continuously adjusting these parameters. This selective application of frequency/phase control reduces the overall complexity of the control system while still achieving EMI mitigation when necessary.
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
The method effectively minimizes electromagnetic interference and reduces power disconnection during low-power transmission, ensuring stable and efficient wireless charging.
Implementation Method 1
capable of supporting an operation of charging various electronic products using a charging pad using a wireless charging system (e.g., a magnetic induction scheme or a resonance scheme)
Implementation Method 2
capable of supporting an operation of charging various electronic products using a charging pad using a wireless charging system (e.g., a magnetic induction scheme or a resonance scheme)
Implementation Method 3
US2018152058A1 relates to wireless charging methods which may reduce degradation due to electro-magnetic interference (EMI) by adjusting the frequency, phase, and/or duty cycle of a control signal for controlling a power generation device
Implementation Method 4
US2018152058A1 relates to wireless charging methods which may reduce degradation due to electro-magnetic interference (EMI) by adjusting the frequency, phase, and/or duty cycle of a control signal for controlling a power generation device
Data Source
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AI summary
A power control method for wireless charging and an electronic device therefor are provided. The electronic device, includes a coil, an inverter including gate inputs which are electrically connected to the coil, and at least one processor. The at least one processor is configured to control the gate inputs of the inverter in an anti-symmetric manner to generate an output power, receive an output power reduction request from an external electronic device, based on receiving the output power reduction request, determine whether a ratio of ON-operations to OFF-operation of the gate inputs of the inverter is less than or equal to a designated ratio, and based on the ratio of ON-operations to OFF-operations of the gate inputs of the inverter being less than or equal to the designated ratio, modulate a phase of a voltage input into the gate inputs of the inverter to generate an output power.