APPARATUS AND METHOD FOR DETECTING FOREIGN OBJECT IN WIRELESS POWER TRANSMITTING SYSTEM

• US 20140232199A1
• Filed: 02/14/2014
• Published: 08/21/2014
• Est. Priority Date: 02/20/2013
• Status: Active Application

• Current Assignee: GE Hybrid Technologies, LLC
• Original Assignee: Spacon Co., Ltd.
• Inventors: JUNG, Chun Kil, HWANG, Byong Uk
• Granted Patent: US 10,848,011 B2
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/40 using two or more transmitting or receiving devices H02J50/50 takes precedence
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• CPC Class Codes: H02J 50/80 involving the exchange of data, concerning supply or distribution of electric power, between transmitting devices and receiving devices
• CPC Class Codes: H02J 7/0029 with safety or protection devices or circuits

Abstract

The present invention provides an apparatus and method for detecting a foreign object in a wireless power transmitting system. The wireless power transmitting apparatus measures an initial transmission power transmitted from the primary core block and performs foreign object detection on the basis of the initial transmission power, once it is found that an initial voltage of an output terminal of the wireless power receiving apparatus connected to an external load is within the range of a reference voltage. By performing foreign object detection while a wireless power receiving apparatus is in an initial setting completion state, before the output of the wireless power receiving apparatus is turned on, delay in detecting foreign objects may be reduced, and a risk due to heating of a foreign object may be avoided.

Claims

1. A wireless power transmitting apparatus detecting a foreign object comprising:

a primary core block coupled with a secondary core block equipped in a wireless power receiving apparatus through magnetic induction or magnetic resonance and configured for transmitting wireless power to the wireless power receiving apparatus by the magnetic induction or the magnetic resonance;

an electric driving unit connected to the primary core block and configured for applying an alternating current (AC) signal required for the primary core block to transmit the wireless power; and

a control unit connected to the electric driving unit and configured for generating a control signal for controlling the AC signal,

wherein the control unit measures an initial transmission power transmitted from the primary core block and performs a foreign object detection on the basis of the initial transmission power, after the control unit determines that an initial voltage of an output terminal of the wireless power receiving apparatus connected to an external load belongs to the range of a reference voltage.

2. The apparatus of claim 1, wherein the control unit compares the initial transmission power with a reference power, and determines that the foreign object has been detected if the initial transmission power is larger than the reference power.

3. The apparatus of claim 1, wherein the control unit checks whether the initial voltage is within the range of the reference voltage by receiving from the wireless power receiving apparatus a foreign object state packet indicating a start of the foreign object detection.

4. The apparatus of claim 3, wherein, after determining that the initial voltage is within the range of the reference voltage, the control unit controls the wireless power transmitting apparatus to enter a foreign object detection phase.

5. The apparatus of claim 3,

wherein the foreign object state packet comprises a preamble, a header, a message, and a checksum,

wherein the header and the message each consist of one byte, and

wherein the value of the header is 0×

05 and the value of the message is 0×

00.

6. A method of detecting one or more foreign objects using a wireless power transmitting apparatus equipped with a primary core block, the method comprising:

applying an alternating current (AC) signal required for transmitting wireless power to the primary core block;

transmitting a power signal to a wireless power receiving apparatus;

checking whether an initial voltage of an output terminal of the wireless power receiving apparatus connected to an external load is within a range of a reference voltage;

measuring an initial transmission power transmitted from the primary core block; and

performing a foreign object detection on the basis of the initial transmission power.

7. The method of claim 6, wherein the performing of the foreign object detection comprises:

comparing the initial transmission power with a reference power; and

determining that one or more foreign objects have been detected if the initial transmission power is larger than the reference power.

8. The method of claim 6, further comprising:

receiving from the wireless power receiving apparatus a foreign object state packet indicating a start of the foreign object detection,

wherein whether the initial voltage is within the range of the reference voltage is checked on the basis of the foreign object state packet.

9. The method of claim 8, wherein, if it is determined that the initial voltage is within the range of the reference voltage, the wireless power transmitting apparatus enters a foreign object detection phase.

10. The method of claim 8,

wherein the foreign object state packet comprises a preamble, a header, a message, and a checksum,

wherein the header and the message each consist of one byte, and

wherein the value of the header is 0×

05 and the value of the message is 0×

00.

11. A wireless power receiving apparatus detecting a foreign object, comprising:

a secondary core block coupled with a primary core block equipped in a wireless power transmitting apparatus through magnetic induction or magnetic resonance and receiving wireless power from the wireless power transmitting apparatus by the magnetic induction or the magnetic resonance;

a rectification unit connected to the secondary core block and configured for providing power to a control unit and an external load by performing full-wave rectification on an alternating current (AC) waveform generated from the secondary core block; and

a control unit configured for measuring an initial voltage of an output terminal connected to the external load and controlling the wireless power receiving apparatus to enter a foreign object detection phase if the initial voltage belongs to a range of a reference voltage.

12. The apparatus of claim 11, wherein the control unit generates a foreign object state packet indicating start of the foreign object detection in the foreign object detection phase and transmits the foreign object state packet to the wireless power transmitting apparatus.

13. The apparatus of claim 12,

wherein the foreign object state packet comprises a preamble, a header, a message, and a checksum,

wherein the header and the message each consist of one byte, and

wherein the value of the header is 0×

05 and the value of the message is 0×

00.

14. A method of detecting one or more foreign objects using a wireless power receiving apparatus equipped with a secondary core block, the method comprising:

receiving a power signal from a wireless power transmitting apparatus;

performing full-wave rectification on an alternating current (AC) waveform generated from the secondary core block;

measuring an initial voltage of an output terminal connected to an external load of the wireless power receiving apparatus; and

controlling the wireless power receiving apparatus to enter a foreign object detection phase if the initial voltage is within a range of a reference voltage.

15. The method of claim 14, further comprising:

generating a foreign object state packet indicating a start of the foreign object detection in the foreign object detection phase; and

transmitting the foreign object state packet to the wireless power transmitting apparatus.

16. The method of claim 15,

wherein the foreign object state packet comprises a preamble, a header, a message, and a checksum,

wherein the header and the message each consist of one byte, and

wherein the value of the header is 0×

05 and the value of the message is 0×

00.