Wireless power delivery in dynamic environments

Patent metadata

Field	Value
Publication number	US-11722017-B2
Application number	US-202117376861-A
Country	US
Kind code	B2
Filing date	Jul 15, 2021
Priority date	May 21, 2012
Publication date	Aug 8, 2023
Grant date	Aug 8, 2023

Abstract

An adaptive system for efficient and long-range wireless power delivery using magnetically coupled resonators responds to changes in a dynamic environment, and maintains high efficiency over a narrow or fixed frequency range. The system uses adaptive impedance matching to maintain high efficiency. The wireless power transfer system includes a drive inductor coupled to a high-Q transmitter coil, and a load inductor coupled to a high-Q receiver coil. The transmitter coil and receiver coil for a magnetically coupled resonator. A first matching network is (i) operably coupled to the drive inductor and configured to selectively adjust the impedance between the drive inductor and the transmitter coil, or (ii) is operably coupled to the load inductor and configured to selectively adjust the impedance between the load inductor and the receiver coil.

First claim

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An adaptive impedance matching wireless power transfer system ( 100 ) comprising:
a drive inductor ( 103 ) configured to receive alternating current electric power from a power source at a fixed frequency;
a high quality factor, (high-Q), transmitter coil ( 104 ) inductively coupled to the drive inductor;
a high-Q receiver coil ( 106 ) configured to be inductively coupled to the transmitter coil; and
a first impedance matching network ( 101 ) that is operably coupled to the drive inductor and configured to selectively adjust the impedance between the drive inductor and the transmitter coil, wherein the first impedance matching network comprises a plurality of capacitors ( 150 ) interconnected to form at least one switchable bank of capacitors, and a microcontroller ( 154 ) operably connected to the at least one switchable bank of capacitors, wherein the microcontroller is configured and operable to receive a measured operating parameter of the adaptive impedance matching wireless power transfer system and to use the measured operating parameter to selectively adjust the impedance between the drive inductor and the transmitter coil,
wherein the first impedance matching network ( 101 ) comprises a first π-match network with variable capacitances comprising a switchable first bank of capacitors ( 150 ) that are connected to a switchable second bank of capacitors ( 152 ) with a π-match inductor, and further wherein the microcontroller ( 154 ) is operably connected to both the switchable first and second banks of capacitors to selectively adjust the capacitance of the first and second banks of capacitors, thereby adjusting the impedance between the drive inductor ( 103 ) and the transmitter coil ( 104 ), wherein each capacitor of the first and second switchable bank of capacitors is coupled to the microcontroller through a network of controllable micro-switches and a gate drive filter, wherein the gate drive filter (Q) comprises a first resistor that couples the gate drive filter to the microcontroller, a second resistor that couples the gate drive filter to a voltage source, a diode (D) that couples the gate driver and filter to the micro-switches and the second resistor, wherein a cathode of the diode is coupled to the gate drive filter, and an anode of the diode is coupled to the microswitches and to the second resistor.

2. The system of claim 1 , wherein the drive inductor ( 103 ) comprises the π-match inductor.

3. The system of claim 1 , wherein the microcontroller ( 154 ) is configured to control the first switchable bank of capacitors ( 150 ) to achieve a capacitance that maximizes the forward transmission gain to the transmitter coil ( 104 ).

4. The system of claim 1 , wherein the microcontroller ( 154 ) is configured to exhaustively engage each combination of the plurality of capacitors to select a configuration that produces a minimum reflected power.

5. The system of claim 1 , wherein the microcontroller ( 154 ) is configured to use the measured operating parameter with a lookup table to selectively engage one or more of the plurality of capacitors.

6. The system of claim 1 , wherein the microcontroller ( 154 ) is configured to monitor a measured performance parameter of the system ( 100 ) and selectively engages a sequence of combinations of the capacitors to optimize the performance parameter.

7. The system of claim 1 , wherein the microcontroller ( 154 ) is configured to monitor one or more monitored operating parameters of the system, to calculate an optimal capacitance based on the monitored operating parameters, and to selectively engage one or more of the capacitors to approximate the calculated optimal capacitance, or wherein the at least one switchable bank of capacitors ( 150 ) comprises at least five capacitors.

Assignees

• Univ Washington Through Its Center For Commercialization

Inventors

• Smith Joshua R
• Waters Benjamin H
• Wisdom Scott
• Sample Alanson P

Classifications

• H02J50/90 Primary

  involving detection or optimisation of position, e.g. alignment · CPC title

• A61M60/178

  drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices · CPC title

• A61M60/216 Primary

  including a rotating member acting on the blood, e.g. impeller · CPC title

• A61M60/523

  using blood flow data, e.g. from blood flow transducers · CPC title

• A61M60/538

  Regulation using real-time blood pump operational parameter data, e.g. motor current · CPC title