Vehicle and contactless power supply system for adjusting impedence based on power transfer efficiency

• US 9,649,946 B2
• Filed: 09/05/2013
• Issued: 05/16/2017
• Est. Priority Date: 09/13/2012
• Status: Active Grant

• Current Assignee: Fujitsu Ten Limited (DENSO Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Fujitsu Ten Limited (DENSO Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Nakamura, Toru, Ichikawa, Shinji, Tokuyama, Kazuma
• Primary Examiner(s): PELTON, NATHANIEL R
• Application Number:
  US14/427,547
• Publication Number:
  US 20150224883A1
• Time in Patent Office: 1,349 Days
• Field of Search: 320108
• CPC Class Codes: B60L 15/2009 for braking
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2220/14 Synchronous machines
• CPC Class Codes: B60L 2240/12 Speed
• CPC Class Codes: B60L 2240/421 Speed
• CPC Class Codes: B60L 2240/423 Torque
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/70 Interactions with external data bases, e.g. traffic centres
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/51 characterised by AC-motors
• 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 53/36 by positioning the vehicle
• CPC Class Codes: B60L 55/00 Arrangements for supplying energy stored within a vehicle to a power network, i.e. vehicle-to-grid [V2G] arrangements
• CPC Class Codes: B60L 58/12 : responding to state of charge [SoC]
• 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 50/90 : involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00036 : Charger exchanging data with battery
• CPC Class Codes: Y02E 60/00 : Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
• CPC Class Codes: Y02T 10/64 : Electric machine technologies in electromobility
• 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: Y04S 10/126 : the energy generation units being or involving electric vehicles [EV] or hybrid vehicles [HEV], i.e. power aggregation of EV or HEV, vehicle to grid arrangements [V2G]

Abstract

A contactless power supply system contactlessly supplies electric power from a power transmitting device to a vehicle. The vehicle includes a power receiving unit contactlessly receiving electric power from the power transmitting device, an electrical storage device storing electric power received by the power receiving unit, and a vehicle ECU. The power transmitting device includes a power supply unit, a power transmitting unit contactlessly supplying electric power, supplied from the power supply unit, to the power receiving unit and a matching transformer used to adjust an impedance between the power supply unit and the power transmitting unit. The vehicle ECU is able to output, to the power transmitting device, a command to adjust the matching transformer, and sets an impedance of the matching transformer on the basis of a power transfer efficiency between the power transmitting unit and the power receiving unit while the electrical storage device is being charged.

Claims

1. A vehicle that contactlessly receives electric power from a power transmitting device of which an impedance is adjustable by a first impedance adjustment unit, comprising:

a power receiving unit configured to contactlessly receive electric power from the power transmitting device;

an electrical storage device configured to store electric power received by the power receiving unit;

an electronic control unit configured to control charging operation of the electrical storage device, the electronic control unit being configured to output a command to adjust the first impedance adjustment unit to the power transmitting device, and the electronic control unit being configured to set an impedance of the first impedance adjustment unit based on a power transfer efficiency between the power transmitting device and the power receiving unit while the electrical storage device is being charged; and

a second impedance adjustment unit configured to adjust an impedance between the power receiving unit and the electrical storage device, wherein

the power transmitting device is configured to use one of a first electric power and a second electric power lower than the first electric power as a transmitted electric power for charging the electrical storage device,

the electronic control unit is configured to cause the power transmitting device to output the first electric power when a value indicating a state of charge of the electrical storage device is lower than or equal to a predetermined threshold, and

the electronic control unit is configured to cause the power transmitting device to output the second electric power and set an impedance of the second impedance adjustment unit based on the transmitted electric power from the power transmitting device, when the value indicating the state of charge exceeds the threshold.

2. The vehicle according to claim 1, further comprising:

a detecting unit configured to detect a vertical distance between the power receiving unit and a ground surface, wherein

the electronic control unit is configured to set the impedance of the first impedance adjustment unit based on the distance detected by the detecting unit.

3. The vehicle according to claim 1, wherein

the electronic control unit is configured to compute a horizontal positional deviation between the power receiving unit and the power transmitting device based on the power transfer efficiency while the electrical storage device is being charged, and the electronic control unit is configured to set the impedance of the first impedance adjustment unit based on a computed positional deviation.

4. The vehicle according to claim 1, further comprising:

a detecting unit configured to detect a vertical distance between the power receiving unit and a ground surface, wherein

the electronic control unit is configured to cause the power transmitting device to transmit an electric power, the electric power is lower than a transmitted electric power at a time when the electrical storage device is charged, in advance of charging of the electrical storage device, and the electronic control unit is configured to set the impedance of the first impedance adjustment unit at a time of starting charging of the electrical storage device based on the power transfer efficiency when the lower electric power is used and the distance.

5. The vehicle according to claim 1, further comprising:

a detecting unit configured to detect a vertical distance between the power receiving unit and a ground surface, wherein

the electronic control unit is configured to assist alignment of the power receiving unit with the power transmitting device based on the power transfer efficiency between the power transmitting device and the power receiving unit while causing the power transmitting device to transmit an electric power, the electric power is lower than a transmitted electric power at a time when the electrical storage device is charged, and the electronic control unit is configured to set the impedance of the first impedance adjustment unit at the time of causing the power transmitting device to transmit the lower electric power based on the distance.

6. The vehicle according to claim 1, wherein

the power transmitting device includes a power transmitting unit configured to contactlessly supply electric power, and

a difference between a natural frequency of the power transmitting unit and a natural frequency of the power receiving unit is smaller than or equal to ±

10% of one of the natural frequency of the power transmitting unit and the natural frequency of the power receiving unit.

7. The vehicle according to claim 1, wherein

the power transmitting device includes a power transmitting unit configured to contactlessly supply electric power, and

a coupling coefficient between the power transmitting unit and the power receiving unit is smaller than or equal to 0.1.

8. The vehicle according to claim 1, wherein

the power transmitting device includes a power transmitting unit configured to contactlessly supply electric power, and

the power receiving unit is configured to receive electric power from the power transmitting unit through at least one of a magnetic field and an electric field, the magnetic field is between the power receiving unit and the power transmitting unit, the magnetic field oscillating at a predetermined frequency, the electric field is between the power receiving unit and the power transmitting unit, and the electric field oscillating at a predetermined frequency.

9. A contactless power supply system that contactlessly supplies electric power, comprising:

a power transmitting device including a power supply unit, a power transmitting unit and an impedance adjustment unit, the power transmitting unit being configured to contactlessly supply electric power, the electric power being supplied from the power supply unit to a power receiving unit, the impedance adjustment unit being electrically connected between the power supply unit and the power transmitting unit, and the impedance adjustment unit being configured to adjust an impedance between the power supply unit and the power transmitting unit; and

a vehicle including the power receiving unit, an electrical storage device and an electronic control unit, the power receiving unit being configured to contactlessly receive electric power from the power transmitting device, the electrical storage device being configured to store electric power received by the power receiving unit, the electronic control unit being configured to control charging operation of the electrical storage device, the electronic control unit being configured to output a command to adjust the impedance adjustment unit to the power transmitting device, and the electronic control unit being configured to set an impedance of the impedance adjustment unit based on a power transfer efficiency between the power transmitting unit and the power receiving unit while the electrical storage device is being charged; and

a second impedance adjustment unit configured to adjust an impedance between the power receiving unit and the electrical storage device, wherein

the power transmitting device is configured to use one of a first electric power and a second electric power lower than the first electric power as a transmitted electric power for charging the electrical storage device,

the electronic control unit is configured to cause the power transmitting device to output the first electric power when a value indicating a state of charge of the electrical storage device is lower than or equal to a predetermined threshold, and

the electronic control unit is configured to cause the power transmitting device to output the second electric power and set an impedance of the second impedance adjustment unit based on the transmitted electric power from the power transmitting device, when the value indicating the state of charge exceeds the threshold.