BIDIRECTIONAL CONTACTLESS POWER TRANSFER SYSTEM

• US 20150001958A1
• Filed: 02/09/2012
• Published: 01/01/2015
• Est. Priority Date: 02/09/2012
• Status: Abandoned Application

• Current Assignee: Technova, Inc. (Aisin Corp.)
• Original Assignee: Technova, Inc. (Aisin Corp.)
• Inventors: Abe, Shigeru, Yasuda, Tomio, Kaneko, Yasuyoshi, Watanabe, Hiroshi
• Application Number:
  US14/377,466
• Publication Number:
  US 20150001958A1
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 15/007 Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• 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 53/22 Constructional details or arrangements of charging converters specially adapted for charging electric vehicles
• CPC Class Codes: B60L 53/34 Plug-like or socket-like devices specially adapted for contactless inductive charging of electric vehicles positioning means for charging devices using inductive energy transfer B60L53/38
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 3/33584 Bidirectional converters
• CPC Class Codes: H02M 7/797 using semiconductor devices only
• 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 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles
• CPC Class Codes: Y02T 90/12 Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles

Abstract

An example according to one embodiment includes a first coil and a second coil spaced apart therefrom. The system is supplied with power from a primary-side circuit to a secondary-side circuit and vice versa. The primary-side circuit includes the first coil. The secondary-side circuit includes the second coil. The primary-side circuit connects to a first converter that converts direct current into alternating current and vice versa. The first converter connects to second converter that converts direct current into alternating current and vice versa, and the second converter further connects to a commercial power supply. The secondary-side circuit connects to third converter that converts direct current into alternating current and vice versa, and the third converter further connects to direct current power supply of a moving body. Bidirectional power transfer is performed only by a switching operation of the first converter, the second converter, and the third converter.

Claims

1. A bidirectional contactless power transfer system comprising:

a contactless power transfer device that includes a first coil and a second coil spaced apart from the first coil, the bidirectional contactless power transfer system being supplied with electrical power from a primary-side circuit to a secondary-side circuit and from the secondary-side circuit to the primary-side circuit by effect of electromagnetic induction, the primary-side circuit including the first coil, the secondary-side circuit including the second coil, wherein

the primary-side circuit in the contactless power transfer device connects to a first power converter having a function to convert direct current into alternating current and a function to convert alternating current into direct current,

the first power converter connects to a second power converter having a function of converting direct current into alternating current and a function of converting alternating current into direct current, and the second power converter further connects to a commercial power supply,

the secondary-side circuit in the contactless power transfer device connects to a third power converter having a function of converting direct current into alternating current and a function of converting alternating current into direct current, and the third power converter further connects to a direct current power supply, such as a secondary battery, of a moving body,

when the power is transferred from the primary-side circuit to the secondary-side circuit in the contactless power transfer device, the second power converter converts alternating current of the commercial power supply into direct current, the first power converter converts the direct current into alternating current to supply the alternating current to the primary-side circuit, and the third power converter converts alternating current output from the secondary-side circuit into direct current to supply the direct current to the direct current power supply of the moving body,

when the power is transferred from the secondary-side circuit to the primary-side circuit in the contactless power transfer device, the third power converter converts direct current output from the direct current power supply of the moving body into alternating current to supply the alternating current to the secondary-side circuit, the first power converter converts alternating current output from the primary-side circuit into direct current, and the second power converter converts the direct current into alternating current and supply the alternating current to the commercial power supply, and

bidirectional power transfer is performed only by switching operation of the first power converter, the second power converter, and the third power converter.

2. The bidirectional contactless power transfer system according to claim 1, wherein the contactless power transfer device includes a first series capacitor connected to the first coil in series, a first parallel capacitor connected to the second coil in parallel, and a first inductor connected to the second coil in series.

3. The bidirectional contactless power transfer system according to claim 1, wherein the contactless power transfer device includes a second parallel capacitor connected to the first coil in parallel, a second inductor connected to the first coil in series, and a second series capacitor connected to the second coil in series.

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

a value Cs of the first or the second series capacitor is set to

Cs≈

1/{(2π

f0)²×

L1},

a value Cp of the first or the second parallel capacitor is set to

Cp≈

1/{(2π

f0)²×

L2}, and

a value Ls of the first or the second series inductor is set to

Ls≈

L2, and wherein

f0 denotes a frequency of alternating current generated by the first power converter of when the power is transferred from the primary-side circuit to the secondary-side circuit in the contactless power transfer device as well as a frequency of alternating current generated by the third power converter of when the power is transferred from the secondary-side circuit to the primary-side circuit in the contactless power transfer device,

L1 denotes a self inductance of the coil to which the first or the second series capacitor is connected, and

L2 denotes a self inductance of the coil to which the first or the second parallel capacitor is connected.

5. The bidirectional contactless power transfer system according to claim 4, wherein

the value Cs of the first or the second series capacitor is set in the range of

Cs0×

0.7≦

Cs≦

Cs0×

1.3,

the value Cp of the first or the second parallel capacitor is set in the range of

Cp0×

0.7≦

Cp≦

Cp0×

1.3, and

the value Ls of the first or the second series inductor is set in the range of

L2×

0.7≦

Ls≦

L2×

1.3, and wherein

Cs0=1/{(2π

f0)²×

L1} and Cp0=1/{(2π

f0)²×

L2}.

6. The bidirectional contactless power transfer system according to claim 1, wherein

at least one of the first power converter and the third power converter includes:

a switching unit arm including two switching units connected in series, each of the switching units being formed of a switching element and a diode connected in inverse-parallel to the switching element; and

a capacitor arm connected to the switching unit arm in parallel and including two capacitors connected in series,

the primary-side circuit or the secondary-side circuit is connected to a connection point between the two switching units of the switching unit arm and to a connection point between the two capacitors of the capacitor arm, and,

if direct current is converted into alternating current, the at least one of the first power converter and the third power converter operates as a half-bridge inverter, and, if alternating current is converted into direct current, the at least one of the first power converter and the third power converter operates as a voltage doubler rectifier circuit.

7. The bidirectional contactless power transfer system according to claim 1, wherein

the third power converter is a three-phase voltage-type inverter, and

a direct current side of the three-phase voltage-type inverter is connected to the direct current power supply of the moving body, and

a three-phase alternating current side of the three-phase voltage-type inverter is connected, via a change-over switch, to a three-phase electric motor and the secondary-side circuit of the contactless power transfer device.

8. The bidirectional contactless power transfer system according to claim 7, wherein,

if the three-phase voltage-type inverter is connected to the three-phase electric motor by the change-over switch, the three-phase voltage-type inverter operates as a three-phase voltage-type PWM inverter, and,

if the three-phase voltage-type inverter is connected to the secondary-side circuit in the contactless power transfer device by the change-over switch, the three-phase voltage-type inverter operates as a single-phase rectangular wave inverter that outputs a single-phase rectangular wave.

9. The bidirectional contactless power transfer system according to claim 3, wherein

a value Cs of the first or the second series capacitor is set to

Cs≈

1/{(2π

f0)²×

L1},

a value Cp of the first or the second parallel capacitor is set to

Cp≈

1/{(2π

f0)²×

L2}, and

a value Ls of the first or the second series inductor is set to

Ls≈

L2, and wherein

f0 denotes a frequency of alternating current generated by the first power converter of when the power is transferred from the primary-side circuit to the secondary-side circuit in the contactless power transfer device as well as a frequency of alternating current generated by the third power converter of when the power is transferred from the secondary-side circuit to the primary-side circuit in the contactless power transfer device,

L1 denotes a self inductance of the coil to which the first or the second series capacitor is connected, and

L2 denotes a self inductance of the coil to which the first or the second parallel capacitor is connected.

10. The bidirectional contactless power transfer system according to claim 9, wherein

the value Cs of the first or the second series capacitor is set in the range of

Cs0×

0.7≦

Cs≦

Cs0×

1.3,

the value Cp of the first or the second parallel capacitor is set in the range of

Cp0×

0.7≦

Cp≦

Cp0×

1.3, and

the value Ls of the first or the second series inductor is set in the range of

L2×

0.7≦

Ls≦

L2×

1.3, and wherein

Cs0=1/{(2π

f0)²×

L1} and Cp0=1/{(2π

f0)²×

L2}.