A CAPACITIVE CONTACTLESS POWERING SYSTEM

• US 20140232185A1
• Filed: 08/14/2012
• Published: 08/21/2014
• Est. Priority Date: 08/16/2011
• Status: Active Grant

• Current Assignee: Signify Holding B.V. (Signify N.V.)
• Original Assignee: Koninklijke Philips Electronics N.V. (Koninklijke Philips N.V.)
• Inventors: Sempel, Adrianus, Waffenschmidt, Eberhard, Van Goor, Dave Willem, Van Der Zanden, Henricus Theodorus
• Granted Patent: US 10,468,912 B2
• Time in Patent Office: Days
• US Class Current: 307/11
• CPC Class Codes: H02J 50/05 using capacitive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: Y10T 29/49117 Conductor or circuit manufacturing

Abstract

A capacitive contactless powering system (100) comprises a pair of receiver electrodes (141, 142) connected to a load (150) through a first inductor (160), wherein the first inductor is coupled to the load to resonate the system; a pair of transmitter electrodes (121, 122) connected to a driver (110); an insulating layer (130) having a first side and a second side opposite each other, wherein the pair of transmitter electrodes are coupled to the first side of the insulating layer and the pair of receiver electrodes are decoupled from the second side of the insulating layer, such that a capacitive impedance is formed between the pair of transmitter electrodes and the pair of receiver electrodes, wherein a power signal generated by the driver is wirelessly transferred from the pair of transmitter electrodes to the pair of receiver electrodes to power the load when a frequency of the power signal matches a series-resonance frequency of the first inductor and the capacitive impedance.

Claims

1. A capacitive powering system, comprising:

a pair of receiver electrodes, having connected in series therebetween, a load with a first inductor, wherein the first inductor is configured with respect of the load to resonate the system;

a pair of transmitter electrodes connected to a driver; and

an insulating layer having a first side and a second side opposite each other, wherein the pair of transmitter electrodes is coupled to the first side of the insulating layer and the pair of receiver electrodes is decoupled from the second side of the insulating layer, such that a capacitive impedance is formed between the pair of transmitter electrodes and the pair of receiver electrodes, wherein a power signal generated by the driver is wirelessly transferred from the pair of transmitter electrodes to the pair of receiver electrodes to power the load when a frequency of the power signal matches a series-resonance frequency of the first inductor and the capacitive impedance.

2. The system of claim 1, wherein the system is tuned to resonate at the series-resonance frequency by at least one of:

changing inductance of the first inductor, changing a position of the receiver electrodes relative to the transmitter electrodes, and changing a frequency of the power signal.

3. The system of claim 1, further comprising a plurality of loads each being connected to a different pair of receiver electrodes and resonating at a different series-resonance frequency, wherein each load of the plurality of loads is powered by the power signal generated by the driver and wirelessly transferred through the pair of transmitter electrodes.

4. The system of claim 3, wherein each load of the plurality of loads resonates at the same series-resonance frequency.

5. The system of claim 3, wherein at least one load of the plurality of loads is protected by a limiter, wherein the limiter is one of a voltage limiter connected in parallel to the at least one load and a current limiter connected in a series to the at least one load.

6. The system of claim 5, wherein the voltage limiter switches off the power signal when an amplitude voltage level on the at least one load is above a reference voltage value.

7. The system of claim 5, wherein the current limiter switches off the power signal when a current flowing through the at least one load is above a reference current value.

8. The system of claim 1, further comprising a matching circuit connected to the pair of receiver electrodes, wherein the matching circuit transforms a resistance of the load to a fixed resistance that is at least equal to a loss resistance of the system.

9. The system of claim 8, wherein the matching circuit is at least a passive matching circuit that comprises a transformer being replaced by the first inductor, and wherein a ratio of a number of turns between a primary coil and a secondary coil of the transformer is selected to increase the load resistance above a value of the loss resistance.

10. The system of claim 8, wherein the matching circuit is at least an active matching circuit including a voltage rectifier, a DC-to-DC converter, and a controller, wherein the controller is configured to measure a voltage level at the rectifier, and change a duty cycle of a charging voltage at the DC-to-DC converter based on the measured voltage level, wherein changing the charging voltage causes an output impedance of the DC-to-DC converter to match an impedance of the load.

11. The system of claim 3, wherein each load of the plurality of loads is at least any one of:

a lamp, a light emitting diode (LED) string, and a LED lamp.

12. The system of claim 11, wherein the insulating layer is part of the receiver electrodes, and wherein the insulating layer is at least any one of:

paper, wood, textile, glass, and a paint layer.

13. The system of claim 12, wherein the system is configured to wirelessly power a plurality of any one of lamps, LED strings, and LED lamps mounted on a large area structure.

14. A method of capacitive contactless power transfer, comprising:

connecting a pair of receiver electrodes to a load and a first inductor, the load and the first inductor connected in series;

connecting a pair of transmitter electrodes to a driver;

forming a capacitive impedance between the pair of transmitter electrodes and the pair of receiver electrodes by;

coupling the pair of transmitter electrodes to a first side of an insulating layer;

decoupling the pair of receiver electrodes from a second side of the insulating layer; and

tuning a frequency of a power signal generated by the driver to match a series-resonance frequency of the first inductor and the capacitive impedance; and

wirelessly transferring the power signal from the pair of transmitter electrodes to the pair of receiver electrodes to power the load when the frequency of the power signal matches a series-resonance frequency of the first inductor and the capacitive impedance.

15. The method of claim 14, further comprising detuning from the series-resonance frequency to control a functionality of the load.