Bidirectional non-contact power supply device and bidirectional non-contact power supply system

• US 10,090,709 B2
• Filed: 09/04/2015
• Issued: 10/02/2018
• Est. Priority Date: 03/23/2015
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: Matsumoto, Sadayuki, Yabumoto, Takuya, Nagai, Takayoshi
• Primary Examiner(s): Kessie, Daniel
• Application Number:
  US15/558,314
• Publication Number:
  US 20180062430A1
• Time in Patent Office: 1,124 Days
• 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: B60M 7/00 Power lines or rails specially adapted for electrically-propelled vehicles of special types, e.g. suspension tramway, ropeway, underground railway
• CPC Class Codes: H02J 50/10 using inductive coupling
• 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: H02M 3/33584 Bidirectional converters
• CPC Class Codes: H02M 3/33592 having a synchronous rectifier circuit or a synchronous freewheeling circuit at the secondary side of an isolation transformer
• 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

Abstract

A bidirectional non-contact power supply device with its electric power transmission efficiency being high is obtained by a simple configuration. In the bidirectional non-contact power supply device, a coil is included for performing electric power transmission to and reception from another coil through a magnetic field coupling therebetween, and the coil and a capacitor being connected in series are connected on an input-output end of an inverter circuit, wherein a bidirectional buck-boost converter is connected between the inverter circuit and a DC power source (7).

Claims

1. A bidirectional non-contact power supply device in which a self coil being coupled with an other coil through a magnetic field coupling therebetween for performing electric power transmission to the other coil or performing electric power reception from the other coil, and a capacitor being connected in series with the self coil are connected to a first input-output end in an inverter circuit;

a first input-output end in a bidirectional buck-boost converter is connected to a second input-output end in the inverter circuit; and

a DC power source is connected to a second input-output end in the bidirectional buck-boost converter, wherein in the bidirectional non-contact power supply device;

the bidirectional buck-boost converter includes an upper-stage semiconductor switching device used at a time of buck operation, and a lower-stage semiconductor switching device used at a time of boost operation;

the bidirectional buck-boost converter converts, at a time of electric power transmission, electric power supplied from the DC power source to a voltage of the DC power source or less whose voltage is inputted into the inverter circuit;

the bidirectional buck-boost converter converts, at a time of electric power reception, electric power outputted from the inverter circuit to an output voltage of the inverter circuit or more whose output voltage is supplied to the DC power source;

the bidirectional buck-boost converter controls, at a time of electric power reception, the lower-stage semiconductor switching device so that its duty ratio is gradually made smaller from a duty ratio at a time when the electric power reception starts; and

the bidirectional buck-boost converter controls, after electric output power to the DC power source reaches an instruction value determined in advance, the duty ratio of the lower-stage semiconductor switching device so that the electric output power thereto is maximized.

2. The bidirectional non-contact power supply device as set forth in claim 1, wherein the bidirectional buck-boost converter controls, at a time of starting electric power reception, to turn off the upper-stage semiconductor switching device used for buck operation and also to set a duty ratio of the lower-stage semiconductor switching device used for boost operation at 100 percent, and controls the duty ratio thereof so as to be gradually made smaller.

3. The bidirectional non-contact power supply device as set forth in claim 1, wherein

the bidirectional buck-boost converter

controls, after electric power reception is started and electric output power therefrom to the DC power source reaches a value of electric power determined in advance, so that the electric output power thereto is maximized using a hill-climbing method, and controls so that electric power inputted into the bidirectional buck-boost converter or into the inverter circuit is made constant at a time of electric power transmission.

4. The bidirectional non-contact power supply device as set forth in claim 1, wherein

the inverter circuit is made of a full-bridge circuit constituted of semiconductor switching devices each having a feedback diode;

the bidirectional buck-boost converter has a control mode in which, at a time of electric power reception in a state in which the lower-stage semiconductor switching device is turned on and the upper-stage semiconductor switching device is turned off, when defining as a positive direction a direction of an electric current flowing from the capacitor connected in series with the self coil into the inverter circuit made of the full-bridge circuit and defining as a negative direction a direction of an electric current flowing from the self coil into the inverter circuit made of the full-bridge circuit, lower-side semiconductor switching devices of the inverter circuit made of the full-bridge circuit are turned on, and upper-side semiconductor switching devices of the inverter circuit made of the full-bridge circuit are turned off, when an electric current flows toward the positive direction; and

the upper-side semiconductor switching devices of the inverter circuit made of the full-bridge circuit are turned on, and the lower-side semiconductor switching devices of the inverter circuit made of the full-bridge circuit are turned off, when an electric current flows toward the negative direction.

5. A bidirectional non-contact power supply system, comprising

the bidirectional non-contact power supply devices as set forth in claim 1 as a first bidirectional non-contact power supply device and a second bidirectional non-contact power supply device, wherein

a self coil of the first bidirectional non-contact power supply device and a self coil of the second bidirectional non-contact power supply device are magnetically coupled with each other.