Wireless power transmission system capable of continuing power transmission while suppressing heatup of foreign objects

• US 10,250,082 B2
• Filed: 04/05/2017
• Issued: 04/02/2019
• Est. Priority Date: 11/02/2012
• Status: Active Grant

• Current Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Original Assignee: Panasonic Intellectual Property Management Co., Ltd. (Panasonic Holdings Corporation)
• Inventors: Kanno, Hiroshi, Asanuma, Kenichi
• Primary Examiner(s): Kessie, Daniel
• Application Number:
  US15/479,688
• Publication Number:
  US 20170207668A1
• Time in Patent Office: 727 Days
• CPC Class Codes: B60L 2200/12 Bikes
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 50/20 using propulsion power generated by humans or animals
• CPC Class Codes: B60L 53/124 Detection or removal of foreign bodies
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/51 Photovoltaic means
• CPC Class Codes: H01F 38/14 Inductive couplings for wireless supply or distribution of electric power using inductive coupling H02J50/10
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• 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 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/35 with light sensitive cells
• 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

Abstract

A power transmitting antenna includes a first resonant circuit including a power transmitting coil, a power receiving antenna includes a second resonant circuit including a power receiving coil. When the power transmitting antenna and the power receiving antenna are electromagnetically coupled to each other, the power transmitting antenna and the power receiving antenna have an odd-mode resonance frequency corresponding to an odd-mode resonant condition, and an even-mode resonance frequency corresponding to an even-mode resonant condition, and the even-mode resonance frequency is higher than the odd-mode resonance frequency. A wireless power transmitting apparatus is provided with a power transmitting circuit configured to generate high-frequency power at a variable frequency, and supply the high-frequency power to the power transmitting antenna. A control circuit sets the frequency of the high-frequency power generated by the power transmitting circuit to one of the odd-mode resonance frequency and the even-mode resonance frequency.

Claims

1. A control circuit of a wireless power transmitting apparatus in a wireless power transmission system for transmitting high-frequency power from the wireless power transmitting apparatus comprising a power transmitting antenna to a power receiving antenna,

wherein the power transmitting antenna includes a first resonant circuit including a power transmitting coil, wherein the power receiving antenna includes a second resonant circuit including a power receiving coil,

wherein, when the power transmitting antenna and the power receiving antenna are electromagnetically coupled to each other, the power transmitting antenna and the power receiving antenna have an odd-mode resonance frequency corresponding to an odd-mode resonant condition, and an even-mode resonance frequency corresponding to an even-mode resonant condition, and the even-mode resonance frequency is higher than the odd-mode resonance frequency,

wherein the wireless power transmitting apparatus further comprises a power transmitting circuit configured to generate, from input power, high-frequency power at a variable frequency, and

supply the high-frequency power to the power transmitting antenna, under control of the control circuit of the wireless power transmitting apparatus, and wherein the control circuit of the wireless power transmitting apparatus sets the frequency of the high-frequency power generated by the power transmitting circuit to one of the odd-mode resonance frequency and the even-mode resonance frequency and

wherein the control circuit of the wireless power transmitting apparatus repeatedly alternates a first time interval and a second time interval, the first time interval has a first continuous operating time during which the frequency of the high-frequency power generated by the power transmitting circuit is set to the odd-mode resonance frequency, and the second time interval has a second continuous operating time during which the frequency of the high-frequency power generated by the power transmitting circuit is set to the even-mode resonance frequency.

2. The control circuit of the wireless power transmitting apparatus as claimed in claim 1, wherein the first continuous operating time is set to be shorter than a shortest period of time during which a temperature of a foreign object reaches a threshold temperature, when high-frequency power is transmitted at the odd-mode resonance frequency and the foreign object is present near the power transmitting coil or the power receiving coil, and wherein the second continuous operating time is set to be shorter than a shortest period of time during which a temperature of a foreign object reaches the threshold temperature, when high-frequency power is transmitted at the even-mode resonance frequency and the foreign object is present near the power transmitting coil or the power receiving coil.

3. The control circuit of the wireless power transmitting apparatus as claimed in claim 2, wherein the control circuit of the wireless power transmitting apparatus reduces the first continuous operating time and the second continuous operating time, when detecting an abnormal condition due to a foreign object near the power transmitting coil or the power receiving coil using a sensor configured to detect the abnormal condition.

4. The control circuit of the wireless power transmitting apparatus as claimed in claim 1, wherein the control circuit of the wireless power transmitting apparatus stops the transmission of the high-frequency power, when detecting an abnormal condition due to a foreign object near the power transmitting coil or the power receiving coil using a sensor configured to detect the abnormal condition.

5. A wireless power transmitting apparatus in a wireless power transmission system for transmitting high-frequency power from the wireless power transmitting apparatus comprising a power transmitting antenna to a power receiving antenna, the wireless power transmitting apparatus comprising:

a control circuit of the wireless power transmitting apparatus;

a power transmitting antenna including a first resonant circuit including a power transmitting coil; and

a power transmitting circuit configured to generate, from input power, high-frequency power at a variable frequency, and supply the high-frequency power to the power transmitting antenna, under control of the control circuit of the wireless power transmitting apparatus,

wherein the power receiving antenna includes a second resonant circuit including a power receiving coil,

wherein, when the power transmitting antenna and the power receiving antenna are electromagnetically coupled to each other, the power transmitting antenna and the power receiving antenna have an odd-mode resonance frequency corresponding to an odd-mode resonant condition, and an even-mode resonance frequency corresponding to an even-mode resonant condition, and the even-mode resonance frequency is higher than the odd-mode resonance frequency,

and

wherein the control circuit of the wireless power transmitting apparatus sets the frequency of the high-frequency power generated by the power transmitting circuit to one of the odd-mode resonance frequency and the even-mode resonance frequency and

wherein the control circuit of the wireless power transmitting apparatus repeatedly alternates a first time interval and a second time interval, the first time interval has a first continuous operating time during which the frequency of the high-frequency power generated by the power transmitting circuit is set to the odd-mode resonance frequency, and the second time interval has a second continuous operating time during which the frequency of the high-frequency power generated by the power transmitting circuit is set to the even-mode resonance frequency.

6. The wireless power transmitting apparatus as claimed in claim 5, wherein an output impedance for a case where an input terminal of the power transmitting antenna is seen from an output terminal of the power transmitting circuit is set to be substantially equal to an input impedance for a case where the output terminal of the power transmitting circuit is seen from the input terminal of the power transmitting antenna.

7. A wireless power transmission system for transmitting high-frequency power from a wireless power transmitting apparatus comprising a power transmitting antenna to a power receiving antenna, wherein the wireless power transmitting apparatus comprises:

a control circuit of the wireless power transmitting apparatus;

a power transmitting antenna including a first resonant circuit including a power transmitting coil;

a power transmitting circuit configured to generate, from input power, high-frequency power at a variable frequency, and supply the high-frequency power to the power transmitting antenna, under control of the control circuit of the wireless power transmitting apparatus,

wherein the power receiving antenna includes a second resonant circuit including a power receiving coil, wherein, when the power transmitting antenna and the power receiving antenna are electromagnetically coupled to each other, the power transmitting antenna and the power receiving antenna have an odd-mode resonance frequency corresponding to an odd-mode resonant condition, and an even-mode resonance frequency corresponding to an even-mode resonant condition, and the even-mode resonance frequency is higher than the odd-mode resonance frequency,

and

wherein the control circuit of the wireless power transmitting apparatus sets the frequency of the high-frequency power generated by the power transmitting circuit to one of the odd-mode resonance frequency and the even-mode resonance frequency and

wherein the control circuit of the wireless power transmitting apparatus repeatedly alternates a first time interval and a second time interval, the first time interval has a first continuous operating time during which the frequency of the high-frequency power generated by the power transmitting circuit is set to the odd-mode resonance frequency, and the second time interval has a second continuous operating time during which the frequency of the high-frequency power generated by the power transmitting circuit is set to the even-mode resonance frequency.

8. The wireless power transmission system as claimed in claim 7, wherein the power receiving antenna is connected to a load apparatus, and wherein an output impedance for a case where the load apparatus is seen from an output terminal of the power receiving antenna is set to be substantially equal to an input impedance for a case where the output terminal of the power receiving antenna is seen from the load apparatus.