Power-transmitting device and wireless power transmission system

• US 10,177,591 B2
• Filed: 08/15/2016
• Issued: 01/08/2019
• Est. Priority Date: 03/18/2014
• Status: Active Grant

• Current Assignee: IHI Corporation
• Original Assignee: IHI Corporation
• Inventors: Takatsu, Yuji, Araki, Jun
• Primary Examiner(s): Fantu, Yalkew
• Application Number:
  US15/236,540
• Publication Number:
  US 20160352139A1
• Time in Patent Office: 876 Days
• Field of Search: 320108
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/527 Voltage
• CPC Class Codes: B60L 2240/529 Current
• 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: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• 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: H02J 7/00034 Charger exchanging data with an electronic device, i.e. telephone, whose internal battery is under charge
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• 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 90/14 Plug-in electric vehicles

Abstract

A power-transmitting device transmits AC power generated in an inverter circuit to a power receiving device in a wireless manner by magnetically coupling a power-transmitting coil to a power-receiving coil of the power receiving device. The power-transmitting device is provided with a power transmission controller which controls the aforementioned inverter circuit to change the AC power in accordance with information relating to the state of power transmission to a load connected to the power-receiving device.

Claims

1. A power-transmitting device transmitting AC power generated in an inverter circuit to a power-receiving device in a wireless manner by magnetically coupling a power-transmitting coil to a power-receiving coil of the power-receiving device, the power-transmitting device comprising

a power transmission controller controlling the inverter circuit to change the AC power in accordance with information relating to a state of power transmission to a load connected to the power-receiving device;

and

an acquisition unit acquiring the information from the power receiving device.

2. The power-transmitting device according to claim 1,

wherein the load is a secondary battery, the acquisition unit acquires, as the information, an instruction to reduce the power transmission to the secondary battery, and the power transmission controller changes the AC power according to the information.

3. The power-transmitting device according to claim 2,

wherein the power transmission controller controls the inverter circuit so that a phase difference between the output current and the output voltage of the inverter circuit increases as a charging state of the secondary battery becomes close to a fully-charged state.

4. The power-transmitting device according to claim 1,

wherein the load is a secondary battery, and the power transmission controller determines a timing of a reduction in the power transmission to the secondary battery according to the information and changes the AC power based on a result of the determination.

5. The power-transmitting device according to claim 4,

wherein the acquisition unit acquires the information once after the transmission of the AC power is initiated, the power-transmitting device comprises a storage unit in which a relationship between a charging time of the secondary battery and the information is stored in advance, and the power transmission controller determines the timing of the reduction in the power transmission to the secondary battery according to the relationship and the information.

6. The power-transmitting device according to claim 5,

wherein the storage unit stores a relationship between the charging time and charging power of the secondary battery for each of secondary batteries having different characteristics.

7. The power-transmitting device according to claim 4,

wherein the information is a charging voltage or impedance of the secondary battery.

8. The power-transmitting device according to claim 1,

wherein the load is a secondary battery, the power-transmitting device comprises a storage unit in which a relationship between impedance of the load and a timing of a change in the AC power is stored, and the power transmission controller identifies the impedance of the load according to an input current and an input voltage of the inverter circuit or an output current and an output voltage of the inverter circuit and changes the AC power according to the identified impedance and the relationship.

9. The power-transmitting device according to claim 1,

wherein the power transmission controller adjusts a switching frequency of the inverter circuit.

10. The power-transmitting device according to claim 1,

wherein the power transmission controller adjusts an ON/OFF duty ratio of the inverter circuit.

11. The power-transmitting device according to claim 1,

wherein the power transmission controller adjusts a switching phase difference between two legs where two switching elements in the inverter circuit are connected in series.

12. A wireless power transmission system comprising:

the power-transmitting device; and

the power receiving device according to claim 1.

13. The wireless power transmission system according to claim 12,

wherein the power-receiving device includes a power-receiving rectifier circuit rectifying the AC power received from the power-transmitting coil by the power-receiving coil and transmitting the rectified AC power to the secondary battery as the load, and a provider providing the power-transmitting device with the information relating to the state of the power transmission.