Wireless Vehicle Charging Resonant Coupling
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Solution Overview
Problem
Current wireless energy transfer methods are inefficient for transferring useful amounts of electrical power over mid-range distances and alignment offsets, as traditional induction schemes have limited range and radiative schemes pose hazards and require line-of-sight and complex tracking mechanisms.
Innovation Solution
The use of coupled electromagnetic resonators with long-lived oscillatory resonant modes to mediate energy transfer through magnetic or electric near-fields, allowing for efficient wireless energy transfer over mid-range distances with high-quality factor resonators and sub-wavelength resonators that extend their near-fields, enabling efficient power delivery from picowatts to kilowatts.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If traditional induction schemes are used for wireless energy transfer, then power transfer is achieved over very short distances, but the transfer distance and alignment tolerance are severely limited
Solution Approach 1:
The patent applies resonant oscillation at specific frequencies (e.g., 6.78 MHz) to both transmitting and receiving coils, creating a resonant coupling effect that dramatically extends the wireless power transfer distance from millimeters to meters while maintaining high efficiency. The resonant frequency matching between transmitter and receiver creates a strongly coupled oscillating magnetic field that bridges the gap between coils.
Solution Approach 2:
The patent changes the operating parameters by using high-Q factor resonant coils with specific inductance and capacitance values tuned to a resonant frequency. This parameter optimization allows the system to operate efficiently at extended distances compared to traditional induction, transforming the system from a near-field inductive coupling to a resonant inductive coupling regime.
2Length of stationary object
If radiative wireless energy transfer schemes are used, then power can be transmitted over longer distances, but hazards are posed to objects or people intersecting the beam and line-of-sight requirements are imposed
Solution Approach 1:
By using resonant oscillation at a specific frequency (6.78 MHz) with high-Q factor coils, the system creates a confined oscillating magnetic field that extends the transfer distance to meters while avoiding the hazards of radiative electromagnetic waves. The resonant coupling confines the energy transfer to a controlled near-field region that does not pose safety risks to nearby objects or personnel.
Solution Approach 2:
The patent uses an oscillating magnetic field as an intermediary carrier between the transmitting and receiving coils. This magnetic near-field mediator enables power transfer over extended distances without requiring line-of-sight and without the harmful effects of radiative electromagnetic waves, as the magnetic field is confined to the near-field region around the coils.
3Loss of energy
If radiative wireless energy transfer schemes are used, then directional antennas can confine energy towards the receiver, but complicated tracking and steering mechanisms are required for mobile transmitters and receivers
Solution Approach 1:
The resonant oscillation at a fixed frequency creates a strongly coupled magnetic field that maintains energy confinement without requiring directional tracking. The high-Q factor resonant coils naturally confine the magnetic flux to a controlled region, eliminating the need for complex tracking and steering mechanisms that would be required for mobile applications.
Solution Approach 2:
The resonant wireless power transfer system provides universal applicability for both stationary and mobile applications without requiring different mechanisms. The same resonant coupling principle works effectively whether the transmitter or receiver is stationary or moving, eliminating the need for specialized tracking mechanisms.
4Ease of operation
If traditional induction schemes are used, then wireless energy transfer is achieved, but only over very short distances with very small offset tolerances
Solution Approach 1:
By using resonant oscillation at matched frequencies between transmitter and receiver coils, the system achieves both extended transfer distance (meters) and relaxed alignment tolerance. The resonant coupling effect creates a robust magnetic field connection that maintains efficiency even with moderate offsets and misalignments, unlike traditional induction which requires precise alignment over very short distances.
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 enables efficient wireless energy transfer over distances much larger than traditional induction techniques, with improved efficiencies and offset tolerances, safely transferring power to various devices without the limitations of radiative schemes.
Implementation Method 1
a source resonator having a Q-factor Q1 and a characteristic size x1, coupled to a power generator with direct electrical connections; and a second resonator having a Q-factor Q2 and a characteristic size x2, coupled to a load with direct electrical connections, and located a distance D from the source resonator, wherein the source resonator and the second resonator are coupled to exchange energy wirelessly among the source resonator and the second resonator in order to transmit power from the power generator to the load
Implementation Method 2
The use of coupled electromagnetic resonators with long-lived oscillatory resonant modes to mediate energy transfer through magnetic or electric near-fields, allowing for efficient wireless energy transfer over mid-range distances
Data Source
AI summary
A vehicle powering wireless receiver for use with a first electromagnetic resonator coupled to a power supply. The wireless receiver includes a load configured to power the drive system of a vehicle using electrical power, and a second electromagnetic resonator adapted to be housed upon the vehicle and configured to be coupled to the load, wherein the second electromagnetic resonator is configured to be wirelessly coupled to the first electromagnetic resonator to provide resonant, non-radiative wireless power to the second electromagnetic resonator from the first electromagnetic resonator; and wherein the field of at least one of the first electromagnetic resonator and the second electromagnetic resonator is shaped using a conducting surface to avoid a loss-inducing object.