Contactless power transfer apparatus

• US 9,457,676 B2
• Filed: 02/07/2012
• Issued: 10/04/2016
• Est. Priority Date: 02/10/2011
• Status: Expired due to Fees

• Current Assignee: Technova, Inc. (Aisin Corp.), National University Corporation Saitama University
• Original Assignee: Technova, Inc. (Aisin Corp.), National University Corporation Saitama University
• Inventors: Abe, Shigeru, Yasuda, Tomio, Suzuki, Akira
• Primary Examiner(s): Barnie, Rexford
• Assistant Examiner(s): TRAN, THAI H
• Application Number:
  US13/984,148
• Publication Number:
  US 20130313912A1
• Time in Patent Office: 1,701 Days
• Field of Search: 307/104
• US Class Current: 1/1
• 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 2250/10 by alarm
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• 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 53/126 Methods for pairing a vehicle and a charging station, e.g. establishing a one-to-one relation between a wireless power transmitter and a wireless power receiver
• CPC Class Codes: B60L 53/305 Communication interfaces
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• 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 50/005 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 50/402 the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas
• CPC Class Codes: H02J 50/70 involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02M 3/335 using semiconductor devices only
• 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
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

According to one embodiment, contactless power transfer apparatus includes: transmission coil; primary capacitor; reception coil opposing transmission coil through gap; and secondary capacitor. Specification of frequency of the transmission coil and that of the reception coil are equal. At least one of electrical power specification and gap length specification of the transmission coil differ from the reception coil. When the electrical power specification of the power transmission coil differ from that of the power reception coil, the power is supplied from the transmission coil to the reception coil by using smaller one of the power of the transmission coil and of the reception coil as maximum power. When the gap length specification of the transmission coil differs from that of the reception coil, the transmission coil opposes the reception coil through the gap length, which is the specification of the transmission coil.

Claims

1. A contactless power transfer apparatus comprising:

a power transmission coil;

a primary side capacitor connected to the power transmission coil in series or parallel;

a power reception coil opposing the power transmission coil through a gap; and

a secondary side resonant capacitor connected to the power reception coil in parallel, wherein

power is supplied from the power transmission coil to the power reception coil,

the power transmission coil and the power reception coil includes;

a rectangular or H-shaped core having magnetic pole portions at both ends; and

a wire wound around a core part between the magnetic pole portions,

a specification of a power source frequency of the power transmission coil and a specification of a resonance frequency of the power reception coil are equal to each other,

at least one of a specification of an electrical power and a specification of a gap length of the power transmission coil is different from corresponding specification of the power reception coil,

when the specification of the electrical power of the power transmission coil and the specification of the electrical power of the power reception coil differ from each other, the power is supplied from the power transmission coil to the power reception coil by using smaller one of the electrical power of the power transmission coil and the electrical power of the power reception coil as a maximum electrical power capable of being supplied, and

when the specification of the gap length of the power transmission coil and the specification of the gap length of the power reception coil differ from each other, the power is supplied by having the power transmission coil and the power reception coil oppose each other through the gap length, which is the specification of the power transmission coil.

2. The contactless power transfer apparatus of claim 1, wherein a number of turns of the wire wound around the core part of the power reception coil is constant.

3. The contactless power transfer apparatus of claim 2, wherein, when the specification of the gap length of the power transmission coil is the same as the specification of the gap length of the power reception coil, a number of turns of the wire wound around the core part of the power transmission coil is equal to a number of turns of the wire wound around a regular power transmission coil of the power reception coil, the regular power transmission coil having a specification of the electrical power and a specification of a gap length that are the same as the specification of the electrical power and the specification of the gap length of the power reception coil.

4. The contactless power transfer apparatus of claim 2, wherein, when the specification of the gap length of the power transmission coil is longer than the specification of the gap length of the power reception coil, a number of turns of the wire wound around the core part of the power transmission coil is greater than a number of turns of the wire wound around a regular power transmission coil of the power reception coil, the regular power transmission coil having a specification of the electrical power and a specification of the gap length that are the same as the specification of the electrical power and the specification of the gap length of the power reception coil.

5. The contactless power transfer apparatus of claim 1, wherein, when a coupling factor between the power transmission coil and the power reception coil is KAB, a coupling factor between the power transmission coil and a regular power reception coil, which has a specification of the electrical power and a specification of the gap length the same as the specification of the electrical power and the specification of the gap length of the power transmission coil, of the power transmission coil is KA, and a coupling factor between the power reception coil and a regular power transmission coil, which has a specification of the electrical power and a specification of the gap length the same as the specification of the electrical power and the specification of the gap length of the power reception coil, of the power reception coil is KB,

0.5KA≦

KAB≦

2KA and 0.5KB≦

KAB≦

2KB.

6. The contactless power transfer apparatus of claim 1, wherein, when a length of the magnetic pole part of the power transmission coil is LA, a width thereof is WA, a distance between the magnetic pole parts at the both ends of the core is DA, a length of the magnetic pole parts of the power reception coil is LB, a width thereof is WB, and a distance between the magnetic pole parts at the both ends of the core is DB,

0.5×

LB≦

LA≦

2×

LB

DB≦

DA≦

DB+2×

WB or DA≦

DB≦

DA+2×

WA.

7. The contactless power transfer apparatus of claim 1, wherein, a value CP of the secondary side resonant capacitor connected in parallel to the power reception coil is set so as to resonate with L2 at a power source frequency f0, L2 being a self-inductance of the power reception coil in a state in which the power transmission coil having a specification the same as the specification of the power reception coil is placed at a position of a gap length in an open state.

8. The contactless power transfer apparatus of claim 7, wherein

the primary side capacitor is connected in series between the power transmission coil and a high frequency power source, and

a value CS of the primary side capacitor is set so that an output power factor of the high frequency power source becomes one by connecting the secondary side resonant capacitor CP and the resistance load RL in parallel to the power reception coil.

9. The contactless power transfer apparatus of claim 8, further comprising an adjustment unit that adjusts the value CS of the primary side capacitor, wherein

the adjustment unit adjusts the value CS of the primary side capacitor so that the output power factor of the high frequency power source becomes one.

10. The contactless power transfer apparatus of claim 1, wherein the specification of the electrical power of the power transmission coil and the specification of the electrical power of the power reception coil differ from each other by more than twice.

11. The contactless power transfer apparatus of claim 1, wherein the specification of the gap length of the power transmission coil and the specification of the gap length of the power reception coil differ from each other by more than 1.5 times.