Wireless Power Transmitter Phase Control for Magnetic Field Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wireless power transfer systems face challenges in reducing magnetic field emissions when multiple base wireless charging systems are activated simultaneously, which can exceed safety and emission thresholds, posing risks to implantable medical devices and other objects.
Innovation Solution
Implementing a communication link between local distribution centers and base wireless charging systems to synchronize and control the phase difference of currents in adjacent systems, ensuring that the magnetic fields generated by these systems have a specific phase difference, thereby reducing the combined magnetic field strength in overlapping regions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple wireless power transmitters are activated simultaneously to provide wireless charging, then power transfer capability is improved, but magnetic field emission increases beyond safety thresholds
Solution Approach 1:
The patent implements periodic action by alternating the activation of multiple wireless power transmitters in time-based cycles. Instead of simultaneous operation, transmitters are activated sequentially with controlled timing, allowing magnetic fields to be generated in alternating periods. This periodic operation maintains overall power transfer capability while ensuring that at any given moment, only limited transmitters are active, thereby keeping magnetic field emissions within safety thresholds.
Solution Approach 2:
The patent applies parameter changes by dynamically adjusting the phase and timing parameters of current supplied to each wireless power transmitter. By modifying the temporal parameters (phase shifts, duty cycles, activation timing) of the transmitters, the system optimizes power transfer efficiency while controlling the superposition of magnetic fields. This parameter adjustment ensures that combined magnetic field strength remains below harmful thresholds even when multiple transmitters operate in proximity.
2Area of stationary object
If multiple base wireless charging systems operate in adjacent regions, then charging coverage area is expanded, but combined magnetic field strength exceeds emission standards
Solution Approach 1:
The patent implements periodic action by coordinating the operational cycles of adjacent base wireless charging systems. Each system operates in synchronized periods where one system is active while others are in standby or reduced-power mode. This temporal separation allows the service area to be effectively expanded through multiple systems without causing harmful magnetic field superposition in overlapping regions, as the systems take turns providing power transfer services.
Solution Approach 2:
The patent applies preliminary action by pre-coordinating the activation schedules and phase relationships of adjacent wireless charging systems before simultaneous operation begins. The controller circuits establish predetermined timing patterns and phase shifts in advance, ensuring that when multiple systems are deployed to expand coverage, their magnetic field emissions are already configured to minimize combined field strength. This preliminary coordination prevents harmful emissions from occurring in the first place.
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 effectively minimizes the combined magnetic field strength, ensuring compliance with safety and emission standards, even when multiple systems are operating simultaneously, thereby reducing potential interference and risks.
Implementation Method 1
a first current provided to the first wireless power transmitter, the first current generating a first magnetic field
Implementation Method 2
a second current to the second wireless power transmitter, the second current generating a second magnetic field
Implementation Method 3
a second phase having a phase difference between the first phase that reduces a magnitude of a combined magnetic field of the first and second magnetic fields
Data Source
AI summary
In an aspect of the disclosure, an apparatus for wirelessly transmitting power is provided. The apparatus includes a communication circuit configured to communicate with a first wireless power transmitter and a second wireless power transmitter. The apparatus further includes a controller circuit configured to identify a first phase of a first current provided to the first wireless power transmitter, the first current generating a first magnetic field. The controller circuit further determines a time to provide a second current to the second wireless power transmitter. The controller circuit further provides the second current at the determined time with a second phase having a phase difference between the first phase configured to reduce a magnitude of a combined magnetic field of the first and second magnetic fields in a region between the first and second wireless power transmitters.