System and method for increasing operational range of inductive power transmission

Patent metadata

Field	Value
Publication number	US-9843202-B2
Application number	US-201414759377-A
Country	US
Kind code	B2
Filing date	Sep 23, 2014
Priority date	Sep 24, 2013
Publication date	Dec 12, 2017
Grant date	Dec 12, 2017

Abstract

An inductive power transfer system and methods for controlling efficient operational wireless power transfer to an electrical device. The system includes an inductive power outlet, an inductive power receiver and a signal transfer system communicating power transfer instruction from receiver to outlet, while transferring power from the outlet to the receiver. The present invention relates to wireless power transfer systems and methods incorporating a current limiter activation mechanism to allow power transfer at an extended operational range, providing a technical solution when an inductive power outlet and an inductive power receiver are laterally misaligned.

First claim

The invention claimed is:

1. A power regulator for an inductive power receiver configured to provide energy to an electric load, said inductive power receiver comprising: at least one secondary inductive coil for forming an inductive couple with at least one primary inductive coil of an inductive power outlet; and a signal transmitter operable to send power control signals to said inductive power outlet, said power regulator comprising:
at least one power monitor operable to monitor power received by the electric load; and
at least one controller in communication with said power monitor and said signal transmitter, said controller operable to instruct said signal transmitter to transmit a power-increase signal if the power received by the electric load is below a minimum power-threshold;
wherein said power regulator further comprises:
a receiver-side signal-timer operable to measure duration of a series of consecutive power-increase signals; and
at least one time-triggered current limiter operable to limit the current required by the electric load thereby reducing said minimum power-threshold, said time-triggered current limiter in communication with said receiver-side signal-timer and configured to activate if said duration of the series of consecutive power-increase signals exceeds a maximum time-threshold.

2. The power regulator of claim 1 , wherein said series of consecutive power-increase signals further comprises a combination of power increase signals and perpetuation signals.

3. The power regulator of claim 1 , wherein said maximum time-threshold is smaller than a transmitter safety disconnection time.

4. The power regulator of claim 3 , said inductive power outlet further comprising an outlet-side signal-timer operable to measure outlet-side duration of a series of consecutive power increase signals received from said signal transmitter,
said inductive power outlet operable to terminate operation if the outlet-side duration exceeds said transmitter safety disconnection time.

5. The power regulator of claim 1 , wherein said signal transmitter comprises a signal transmission circuit comprising at least one electrical element selectively connectable to the secondary inductor by a switching unit, wherein the switching unit is configured to connect the electrical element to the secondary inductor with a characteristic frequency thereby producing a pulse of detectable peaks in primary voltage or primary current having the characteristic frequency.

6. The power regulator of claim 5 , wherein the characteristic frequency of said power-increase signal is about 8 kilohertz.

7. The power regulator of claim 1 , wherein said signal transmitter comprises a signal transmission circuit comprising at least one electrical element selectively connectable to the secondary inductor by a switching unit, wherein the switching unit is configured to connect the electrical element to the secondary inductor according to a differential bi-phase encoding scheme modulating data bits.

8. The power regulator of claim 7 , wherein said power-increase signal comprises a data byte comprising a start bit, 8 data bits, a parity bit, and a single stop bit.

9. The power regulator of claim 8 , wherein said data byte comprises a signed integer value providing a control error packet.

10. A method for regulating power received by an electric load from at least one inductive power outlet via an inductive power receiver, said inductive power receiver comprising:
at least one secondary inductive coil for forming an inductive couple with at least one primary inductive coil associated with said at least one inductive power outlet; and
a power regulator operable to monitor power received by the electric load and to instruct a signal transmitter to transmit a power-increase signal to said at least one inductive power outlet if the power received by the electric load is below a minimum power-threshold;
the method comprising:
measuring a duration of a series of consecutive power-increase signals; comparing the duration of the series of consecutive power-increase signals with a maximum threshold; and
limiting the current required by the electric load if the duration of the series of consecutive power-increase signals exceeds the maximum threshold thereby reducing said minimum power-threshold.

11. The method of claim 10 , further comprising monitoring power received by the electric load, said monitoring comprising one or more of:
comparing power received to said minimum power-threshold; and
comparing power received to a maximum power-threshold.

12. The method of claim 10 , further comprising transmitting control signals to regulate the power received by the electric load.

13. The method of claim 10 , wherein measuring the duration of the series of consecutive power-increase signals comprises:
starting a receiver-side signal-timer when a first of a series of power-increase signals is transmitted; and
resetting said receiver-side signal-timer whenever any other control signal is transmitted.

14. The method of claim 10 , wherein said control signals are selected from at least one of:
a power-increase signal transmitted if the power received by the electric load is below a minimum power-threshold;
a power-decrease signal transmitted if the power received by the electric load is above a maximum power-threshold; and
a perpetuation signal transmitted if the power received by the electric load is above the minimum power-threshold and below the maximum power-threshold.

15. The method of claim 10 , wherein measuring the duration of the series of consecutive power-increase signals comprises:
starting a receiver-side signal-timer when a first of a series of a power-increase signals is transmitted; and
resetting said receiver-side signal-timer whenever a power-decrease signal is transmitted.

16. The method of claim 10 , wherein measuring the duration of the series of consecutive power-increase signals comprises:
starting a receiver-side signal-timer when the power received by the electric load drops below a minimum power-threshold; and
resetting said receiver-side signal-timer when the power received by the electric load rises above the minimum power-threshold.

17. The method of claim 10 , wherein limiting the current comprises activating a time-triggered current limiter.

18. A power regulator for an inductive power receiver configured to provide energy to an electric load, said inductive power receiver comprising: at least one secondary inductive coil for forming an inductive couple with at least one primary inductive coil of an inductive power outlet; and a signal transmitter operable to send power control signals to said inductive power outlet, said power regulator comprising:
at least one power monitor operable to monitor power received by the electric load; and
at least one controller in communication with said power monitor and said signal transmitter, said controller operable to instruct said signal transmitter to transmit a power-increase signal if the power received by the electric load is below a minimum power-threshold;
wherein said power regulator further comprises:
a receiver-side signal-counter operable to count a total-number of a series of consecutive power-increase signals; and
at least one count-triggered current limiter operable to limit the current required by the electric load thereby reducing said minimum power-threshold, said count-triggered current limiter in communication with said receiver-side signal-counter and configured to activate if said total-number of

Assignees

• Powermat Tech Ltd

Inventors

• Kdoshim Moti
• Ashery Moti
• Mach Elieser
• Greenwald Oola
• Cohen-Ogen Itamar

Classifications

• H02J7/025

  Electricity · mapped topic

• H02J50/10

  using inductive coupling · CPC title

• H02J50/80 Primary

  involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices · CPC title

• H02J17/00

  Electricity · mapped topic

• H02J5/005 Primary

  Electricity · mapped topic