Contactless power supplying system with power limiting control

• US 9,537,323 B2
• Filed: 03/20/2014
• Issued: 01/03/2017
• Est. Priority Date: 04/15/2013
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Maikawa, Kengo
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): Warmflash, Michael
• Application Number:
  US14/784,231
• Publication Number:
  US 20160049798A1
• Time in Patent Office: 1,020 Days
• Field of Search: 307/104
• US Class Current: 1/1
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• 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 53/31 Charging columns specially adapted for electric vehicles
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• 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: 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

Provided is a contactless power supplying system which is efficient and can be built of small coils by appropriately limiting power to be inputted into a transmitting coil. In the contactless power supplying system, power transmitted from a transmitting coil is received by a receiving coil by means of magnetic coupling, and the contactless power supplying system includes a power control unit configured to cause power from a power source to flow through the transmitting coil and a control unit configured to perform power limiting control of limiting the power flowing through the transmitting coil by controlling the power control unit.

Claims

1. A contactless power supplying system comprising:

a transmitting coil configured to transmit power;

a power control unit configured to cause power from a power source to flow through the transmitting coil;

a receiving coil configured to receive the power transmitted from the transmitting coil by means of magnetic coupling;

a load to which power outputted from the receiving coil is inputted; and

a control unit configured to perform power limiting control of limiting the power flowing through the transmitting coil by controlling the power control unit, wherein

the control unit is further configured to select a control mode to be employed for the power limiting control based on a coil coupling condition between the transmitting coil and the receiving coil and a magnitude relationship between an induced current and a receiving coil current.

2. The contactless power supplying system according to claim 1, wherein

the control unit has a control mode in which the power is limited in a situation where a load voltage is low and a control mode in which the power is limited in a situation where the load voltage is high,

when the receiving coil current is greater than the induced current, the control unit selects the control mode in which the power is limited in a situation where a load voltage is low, and

when the induced current is greater than the receiving coil current, the control unit selects the control mode in which the power is limited in a situation where the load voltage is high.

3. The contactless power supplying system according to claim 2, wherein

when the control unit selects the control mode in which the power is limited in a situation where a load voltage is low, the control unit starts the flow of power to the transmitting coil at a lowest power level and increases a power command, based on a voltage of the transmitting coil, within such a range that the voltage of the transmitting coil does not exceed an upper limit voltage of the coil, the power command specifying the power to flow through the transmitting coil.

4. The contactless power supplying system according to claim 2, wherein

when the control unit selects the control mode in which the power is limited in a situation where the load voltage is high, the control unit starts the flow of power to the transmitting coil at a power command sent from the load side and reduces a power command specifying the power to flow through the transmitting coil, based on a voltage of the transmitting coil, within such a range that the voltage of the transmitting coil does not exceed an upper limit voltage of the coil.

5. The contactless power supplying system according to claim 3, wherein

the control unit estimates the voltage of the transmitting coil based on the load voltage, the power command, and a voltage of the receiving coil.

6. The contactless power supplying system according to claim 1, wherein the induced current flows through a mutual inductance that occurs between the transmitting coil and the receiving coil.

7. The contactless power supplying system according to claim 1, wherein the receiving coil current flows through the receiving coil.