ELECTRIC MACHINE AND POWER SUPPLY SYSTEM HAVING BATTERY PACK

• US 20110084658A1
• Filed: 10/13/2010
• Published: 04/14/2011
• Est. Priority Date: 10/14/2009
• 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, YAMAMOTO, Hiroshi
• Granted Patent: US 9,114,717 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: B60L 2200/26 Rail vehicles
• CPC Class Codes: B60L 5/005 without mechanical contact between the collector and the power supply line
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: B60L 53/80 Exchanging energy storage elements, e.g. removable batteries
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60M 7/003 for vehicles using stored power (e.g. charging stations)
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 50/005 Mechanical details of housing or structure aiming to accommodate the power transfer means, e.g. mechanical integration of coils, antennas or transducers into emitting or receiving devices
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/342 The other DC source being a battery actively interacting with the first one, i.e. battery to battery charging with circuits for polarity protection H02J7/0034
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 80/10 Efficient use of energy, e.g. using compressed air or pressurized fluid as energy carrier
• 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 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 electric machine and a power supply system, in which a battery pack can be easily and safely replaced with another, and electric power can be transferred with high transfer efficiency. An electric machine of the present invention includes a driving electric motor, a battery pack for supplying electric power to the driving electric motor, and an energy transfer section for transferring electric energy output from the battery pack to the driving electric motor. The battery pack includes a first antenna for receiving electric power from a power supply source located outside the electric machine by coupling with a first resonant magnetic field generated by the power supply source, at least one secondary battery charged by the electric power received by the first antenna, an oscillator for producing radio-frequency power by DC power discharged from the secondary battery, and a second antenna for generating a second resonant magnetic field by the radio-frequency power. The energy transfer section includes a third antenna that couples with the second resonant magnetic field generated by the second antenna, and transfers the radio-frequency power received by the third antenna to the driving electric motor.

Claims

1. An electric machine comprising:

a driving electric motor;

a battery pack for supplying electric power to the driving electric motor; and

an energy transfer section for transferring an electric energy output from the battery pack to the driving electric motor, wherein;

the battery pack includes;

a first antenna for receiving electric power from a power supply source located outside the electric machine by coupling with a first resonant magnetic field generated by the power supply source;

at least one secondary battery charged by the electric power received by the first antenna;

an oscillator for producing radio-frequency power by DC power discharged from the secondary battery; and

a second antenna for generating a second resonant magnetic field by the radio-frequency power; and

the energy transfer section includes a third antenna that couples with the second resonant magnetic field generated by the second antenna, thereby transferring the radio-frequency power received by the third antenna to the driving electric motor.

2. The electric machine of claim 1, wherein:

the first antenna is formed by a first resonant circuit including a first inductor and a first capacitor;

the second antenna is formed by a second resonant circuit including a second inductor and a second capacitor; and

the third antenna is formed by a third resonant circuit including a third inductor and a third capacitor.

3. The electric machine of claim 2, wherein the first inductor, the second inductor and the third inductor are each formed by at least one conductive layer having a spiral shape or a loop shape.

4. The electric machine of claim 2, wherein:

a primary surface of the first inductor is parallel to a first plane; and

a primary surface of the second inductor is parallel to a second plane that intersects with the first plane at an angle of 45°

or more.

5. The electric machine of claim 4, wherein the first plane and the second plane are orthogonal to each other.

6. The electric machine of claim 4, wherein a middle point of a line segment extending between a center of the second inductor as vertically projected onto the first plane and a center of the third inductor as vertically projected onto the first plane is located within an area defined by the primary surface of the first inductor as vertically projected onto the first plane.

7. The electric machine of claim 6, wherein LS<

0.3×

L1 is satisfied, where

L1 denotes an “

size”

of the first inductor as vertically projected onto the first plane, and

LS denotes a distance from the middle point of the line segment extending between the center of the second inductor and the center of the third inductor as vertically projected onto the first plane to a center of the first inductor as vertically projected onto the first plane.

8. The electric machine of claim 1, wherein a resonant frequency of the first antenna is different from a resonant frequency of the second antenna.

9. The electric machine of claim 1, comprising a battery pack holding section for removably holding the battery pack so that the second antenna opposes the third antenna.

10. The electric machine of claim 1, wherein the battery pack is held so that a primary surface of the first inductor is parallel to a ground surface.

11. The electric machine of claim 1, wherein the electric machine is a vehicle having a plurality of wheels.

12. The electric machine of claim 11, wherein:

a size of the first antenna in a traveling direction of the electric machine is smaller than a size of the first antenna in a lateral direction of the electric machine;

a size of the second antenna in a vertical direction is smaller than a size of the second antenna in a lateral direction of the electric machine; and

the first antenna and the second antenna are arranged so that a longitudinal direction of the first antenna and a longitudinal direction of the second antenna coincide with each other.

13. A battery pack comprising:

a first antenna for receiving electric power from a power supply source located outside by coupling with a first resonant magnetic field generated by the power supply source;

at least one secondary battery charged by the electric power received by the first antenna;

an oscillator for producing radio-frequency power by DC power discharged from the secondary battery; and

a second antenna for generating a second resonant magnetic field by the radio-frequency power and magnetically coupling with a third antenna located outside.

14. The battery pack of claim 13, wherein:

the first antenna is formed by a first resonant circuit including a first inductor and a first capacitor; and

the second antenna is formed by a second resonant circuit including a second inductor and a second capacitor.

15. The battery pack of claim 14, wherein the first inductor and the second inductor are each formed by at least one conductive layer having a spiral shape or a loop shape.

16. The battery pack of claim 14, wherein:

a primary surface of the first inductor is parallel to a first plane; and

a primary surface of the second inductor is parallel to a second plane that intersects with the first plane at an angle of 45°

or more.

17. The battery pack of claim 16, wherein the first plane and the second plane are orthogonal to each other.

18. The battery pack of claim 16, wherein a center of the second inductor as vertically projected onto the first plane is located within an area defined by an outline of the first inductor as vertically projected onto the first plane.

19. The battery pack of claim 18, wherein LS<

0.3×

L1 is satisfied, where

L1 denotes an “

size”

of the first inductor as vertically projected onto the first plane, and

LS denotes a distance from a middle point of a line segment extending between the center of the second inductor and the center of the third inductor as vertically projected onto the first plane to a center of the first inductor as vertically projected onto the first plane.

20. The battery pack of claim 13, wherein a resonant frequency of the first antenna is different from a resonant frequency of the second antenna.

21. A power supply system comprising:

a battery pack for supplying electric power to a load;

a first energy transfer section for transferring the electric power output from the battery pack to the load; and

a second energy transfer section for transferring the electric power supplied from outside to the battery pack, wherein

the battery pack includes;

a first antenna for receiving electric power by coupling with a first resonant magnetic field generated by the second energy transfer section;

at least one secondary battery charged by the electric power received by the first antenna;

a first oscillator for producing first radio-frequency power by DC power discharged from the secondary battery; and

a second antenna for generating a second resonant magnetic field by the first radio-frequency power;

the first energy transfer section includes a third antenna that couples with the second resonant magnetic field generated by the second antenna;

the radio-frequency power received by the third antenna is transferred to the load; and

the second energy transfer section includes;

a second oscillator for producing second radio-frequency power by using the electric power supplied from the outside; and

a fourth antenna for generating the first resonant magnetic field by the second radio-frequency power.