Apparatus and method for detecting foreign object in wireless power transmitting system

• US 9,423,439 B2
• Filed: 03/14/2014
• Issued: 08/23/2016
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: GE Hybrid Technologies, LLC (General Electric Company)
• Original Assignee: Hanrim Postech Co., Ltd.
• Inventors: Jung, Chun Kil, Hwang, Byong Uk
• Primary Examiner(s): DO, THUAN V
• Application Number:
  US14/213,923
• Publication Number:
  US 20140266036A1
• Time in Patent Office: 893 Days
• Field of Search: 320/108
• US Class Current: 1/1
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 53/124 Detection or removal of foreign bodies
• CPC Class Codes: B60L 53/66 Data transfer between charging stations and vehicles
• CPC Class Codes: G01R 29/0814 Field measurements related to measuring influence on or from apparatus, components or humans EMC, EMI and similar testing in general G01R31/001, e.g. in ESD, EMI, EMC, EMP testing, measuring radiation leakage; detecting presence of micro- or radiowave emitters; dosimetry; testing shielding; measurements related to lightning
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• 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: H04B 5/26 using coils
• CPC Class Codes: H04B 5/79 for data transfer in combination with power transfer
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

An apparatus and method for detecting a foreign object in a wireless power transmitting system are provided. In a case in which a foreign object is not detected prior to charging, an attempt to detect a foreign object detection during charging is performed, and when a foreign object is not detected while a power signal is being received, power is limited based on a temperature sensor.

Claims

1. A method of detecting a foreign object using at least one processor included in a wireless power receiving apparatus, the method comprising:

performing a first operation of foreign object detection prior to an initial charging;

performing a second operation of foreign object detection during charging if the foreign object is not detected by the first operation of foreign object detection prior to the initial charging; and

performing a third operation of foreign object detection by temperature sensor if the foreign object is not detected by the second operation of foreign object detection during charging,

wherein the first operation of foreign object detection prior to the initial charging comprises;

receiving a power signal at an operating point from a wireless power transmitting apparatus which performs digital ping in a ping phase;

generating a signal strength packet indicating strength of the power signal at the operating point and transmitting the signal strength packet to the wireless power transmitting apparatus;

generating an identification packet indicating a unique ID of the wireless power receiving apparatus and configuration information of the wireless power receiving apparatus, and transmitting the identification packet and the configuration information to the wireless power transmitting apparatus;

measuring a received power and setting an initial voltage;

checking whether the wireless power receiving apparatus is charging;

comparing a required power value with the received power, generating a power control packet based on the comparison result, and transmitting the generated power control packet to the wireless power transmitting apparatus, if the wireless power receiving apparatus is charging;

checking whether the initial voltage is in a hold state and a steady state value of the initial voltage is within a predetermined reference voltage range, if the wireless power receiving apparatus is not charging; and

generating a foreign object state packet, and transmitting the foreign object state packet to the wireless power transmitting apparatus, if the initial voltage is in a hold state and the steady state value of the initial voltage is within the predetermined reference voltage range.

2. The method of claim 1, wherein the second operation of foreign object detection during charging comprises:

receiving wireless power from the wireless power transmitting apparatus if the foreign object is not detected by the wireless power transmitting apparatus.

3. The method of claim 1, wherein the second operation of foreign object detection during charging comprises:

receiving a transmission power measurement report indicating a measured transmission power from the wireless power transmitting apparatus;

detecting a foreign object based on a difference value between the measured transmission power and a measured reception power; and

transmitting an amplitude shift keying (ASK) signal comprising the foreign object detection result to the wireless power transmitting apparatus.

4. The method of claim 3, wherein the transmission power measurement report is transmitted as a frequency shift keying (FSK) signal, and the measured transmission power is obtained by measuring power generated by a primary coil of the wireless power transmitting apparatus.

5. The method of claim 4, wherein the FSK signal is transmitted at least once during each predetermined period, the predetermined period being an interval during which a predetermined number of data signals are transmitted.

6. The method of claim 4, wherein the FSK signal indicates 0 or 1 by switching or selecting a variable frequency of a predetermined range which converts a required fixed power frequency.

7. The method of claim 3, wherein the ASK signal further comprises a required power information as information requiring generation of wireless power based on a magnetic induction scheme by the wireless power transmitting apparatus.

8. A method of detecting a foreign object using at least one processor included in a wireless power receiving apparatus, the method comprising:

performing a first operation of foreign object detection prior to an initial charging; and

performing a second operation of foreign object detection by a temperature sensor if the foreign object is not detected by the first operation of foreign object detection prior to the initial charging,

wherein the first operation of foreign object detection prior to the initial charging comprises;

receiving a power signal at an operating point from a wireless power transmitting apparatus which performs digital ping in a ping phase;

generating a signal strength packet indicating strength of the power signal at the operating point and transmitting the signal strength packet to the wireless power transmitting apparatus;

generating an identification packet indicating a unique ID of the wireless power receiving apparatus and configuration information of the wireless power receiving apparatus and transmitting the identification packet and the configuration information to the wireless power transmitting apparatus;

measuring a received power and setting an initial voltage;

checking whether the wireless power receiving apparatus is charging;

comparing a required power value with the received power, generating a power control packet based on the comparison result, and transmitting the generated power control packet to the wireless power transmitting apparatus, if the wireless power receiving apparatus is charging;

checking whether the initial voltage is in a hold state and a steady state value of the initial voltage is within a predetermined reference voltage range, if the wireless power receiving apparatus is not charging; and

generating a foreign object state packet, and transmitting the foreign object state packet to the wireless power transmitting apparatus, if the initial voltage is in a hold state and the steady state value of the initial voltage is within the predetermined reference voltage range.

9. A wireless power receiving apparatus comprising:

a secondary core block;

a rectifying unit connected to the secondary core block;

a control unit; and

a temperature sensor,

wherein the rectifying unit performs full-wave rectification on an alternating current (AC) waveform generated by the secondary core block and provides power to the control unit and an external load,

wherein the control unit measures an initial voltage of an output terminal connected to the external load, and performs a first operation of foreign object detection if the initial voltage is within a reference voltage range, and

wherein if a foreign object is not detected before charging starts by the first operation of foreign object detection, the control unit performs a second operation of foreign object detection during charging, and if the foreign object is not detected during the second operation of foreign object detection during charging, the control unit performs a third operation of foreign object detection by the temperature sensor,

wherein the control unit performs the second operation of foreign object detection during charging by controlling the wireless power receiving apparatus to receive a transmission power measurement report indicating a measured transmission power from a wireless power transmitting apparatus, to detect the foreign object based on a difference value between the measured transmission power and a measured reception power, and to transmit an amplitude shift keying (ASK) signal comprising the foreign object detection result to the wireless power transmitting apparatus.

10. The wireless power receiving apparatus of claim 9, wherein the transmission power measurement report is transmitted as a frequency shift keying (FSK) signal, and the measured transmission power is obtained by measuring power generated by a primary coil of the wireless power transmitting apparatus.

11. The wireless power receiving apparatus of claim 10, wherein the FSK signal is transmitted at least once during each predetermined period, the predetermined period being an interval during which a predetermined number of data signals are transmitted.

12. The wireless power receiving apparatus of claim 10, wherein the FSK signal indicates 0 or 1 by switching or selecting a variable frequency of a predetermined range which converts a required fixed power frequency.

13. The wireless power receiving apparatus of claim 9, wherein the ASK signal further comprises a required power information as information requiring generation of wireless power based on a magnetic induction scheme by the wireless power transmitting apparatus.