Wireless Charging Transmitter Back Shield for Misalignment Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromagnetic power transfer systems for wireless charging of electric vehicles suffer from inefficiencies in power transmission due to non-uniform spatial distribution of electromagnetic fields and misalignment issues, leading to reduced coupling efficiency and potential heating of objects near the transmitter.
Innovation Solution
The proposed solution involves a transmitter assembly with a primary inductor and a back shield unit, where the back shield has a non-uniform thickness and magnetic permeability profile, and a secondary inductor, which together enhance the spatial distribution of the electromagnetic field, improving uniformity and coupling efficiency while reducing stray radiation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a conventional transmitter coil is used to generate electromagnetic fields for wireless power transfer, then power transmission capability is achieved, but the spatial distribution of the electromagnetic field is non-uniform with highest intensity at the center and reducing toward edges
Solution Approach 1:
The patent applies local quality by varying the thickness of the back shield non-uniformly across different regions. The back shield is thicker at the center region and thinner at the outer regions, creating different magnetic shielding effects in different areas. This non-uniform structure compensates for the non-uniform electromagnetic field distribution, enhancing field uniformity across the transmitter surface while maintaining effective power transmission capability.
2Power
If the transmitter generates strong electromagnetic fields to improve power transmission, then charging power is increased, but efficiency is lost from EM field that is not directed at the receiver and objects near the transmission coil are heated
Solution Approach 1:
The patent converts the harmful stray electromagnetic radiation into a beneficial effect by using the back shield to redirect it. The back shield captures electromagnetic fields that would otherwise radiate harmfully and redirects them to constructively interfere with the primary field, enhancing field uniformity and directing more energy toward the receiver while reducing harmful radiation and heating effects.
3Power
If the transmitter generates strong electromagnetic fields to improve power transmission, then charging power is increased, but efficiency is lost from EM field that is not directed at the receiver
Solution Approach 1:
The back shield acts as an intermediary element between the transmitter coil and the environment. It mediates the electromagnetic field by providing a controlled path for magnetic flux, redirecting stray fields that would otherwise be lost or harmful. This intermediary structure improves the directionality of energy transfer and reduces energy loss from misdirected electromagnetic fields.
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 configuration enhances the uniformity of the electromagnetic field distribution, increases coupling efficiency, and reduces power loss through improved alignment tolerances and reduced heating, thereby increasing the efficiency of wireless charging.
Implementation Method 1
an inverter receives power and generates electromagnetic (EM) Alternating Current (AC) signal that is supplied to a transmitter. The transmitter uses an induction coil to generate an EM field that wirelessly transmits the electromagnetic power. A second induction coil in a receiver installed in an electric vehicle receives the EM field.
Implementation Method 2
The back shield has a non-uniform thickness and magnetic permeability profile, and a secondary inductor, which together enhance the spatial distribution of the electromagnetic field, improving uniformity and coupling efficiency
Data Source
AI summary
Transmitter assemblies and methods for making and using the same. The transmitter assembly can be used for magnetic power transfer. The transmitter assembly can include a primary inductor configured to produce an electromagnetic field. The transmitter assembly can include a back shield unit including a primary back shield that has a first surface proximal to the primary inductor and a second surface opposite to the first surface. The primary back shield is at least partially made of a ferromagnetic material and has a property that is non-uniformly distributed from a center region of the primary back shield to an outer perimeter region of the primary back shield. The property includes a thickness, a magnetic property, or a combination thereof. When used in wireless charging, the transmitter assembly results in improved coupling factor, misalignment tolerance, efficiency, magnetic emissions and z-height coupling distance of a magnetic power transfer profile.