Contactless power transmission device and power transfer system

• US 10,097,043 B2
• Filed: 06/09/2016
• Issued: 10/09/2018
• Est. Priority Date: 07/21/2015
• Status: Active Grant

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Misawa, Takahiro
• Primary Examiner(s): Fureman, Jared
• Assistant Examiner(s): WARMFLASH, MICHAEL J
• Application Number:
  US15/177,932
• Publication Number:
  US 20170025899A1
• Time in Patent Office: 852 Days
• Field of Search: 307104, 307131
• 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: H02M 1/0025 Arrangements for modifying reference values, feedback values or error values in the control loop of a converter
• CPC Class Codes: H02M 1/0051 Diode reverse recovery losses
• CPC Class Codes: H02M 1/0058 by employing soft switching techniques, i.e. commutation of transistors when applied voltage is zero or when current flow is zero using an auxiliary actively switched resonant commutation circuit connected to an intermediate DC voltage or between two push-pull branches of an inverter bridge H02M7/4811; in resonant inverters H02M7/4815; in inverters operating from a resonant DC source H02M7/4826
• CPC Class Codes: H02M 3/3376 with automatic control of output voltage or current
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A control unit executes a first control and a second control. The first control is to control transmission power to target power by adjusting a duty of an output voltage of an inverter. The second control is to control a turn-on current by adjusting the drive frequency, the turn-on current indicating an output current of the inverter at a rising of the output voltage. When the transmission power exceeds a limit value larger than the target power during adjustment of the drive frequency by the second control, the control unit decreases the target power in the first control.

Claims

1. A contactless power transmission device comprising:

a power transmission unit configured to transmit electric power to a power reception device in a contactless manner;

a voltage-source inverter configured to supply transmission power to the power transmission unit in accordance with a drive frequency; and

a control unit configured to control the inverter,

the control unit configured to execute;

a first control for controlling the transmission power to target power by adjusting a duty of an output voltage of the inverter; and

a second control for controlling a turn-on current by adjusting the drive frequency, the turn-on current indicating an output current of the inverter at a rising of the output voltage,

when the transmission power exceeds a limit value larger than the target power during adjustment of the drive frequency by the second control, the control unit being configured to decrease the target power in the first control.

2. The contactless power transmission device according to claim 1, wherein when the transmission power exceeds the limit value during adjustment of the drive frequency by the second control, the control unit is configured to decrease the target power by subtracting a correction amount proportional to an excess amount of the transmission power over the limit value from the target power.

3. The contactless power transmission device according to claim 2, wherein the control unit is configured to decrease the target power by further subtracting a correction amount proportional to an integrated value of the excess amount from the target power.

4. A power transfer system comprising:

a power transmission device; and

a power reception device,

the power transmission device including;

a power transmission unit configured to transmit electric power to the power reception device in a contactless manner;

a voltage-source inverter configured to supply transmission power to the power transmission unit in accordance with a drive frequency; and

a control unit configured to control the inverter,

the control unit configured to execute;

a first control for controlling the transmission power to target power by adjusting a duty of an output voltage of the inverter; and

a second control for controlling a turn-on current by adjusting the drive frequency, the turn-on current indicating an output current of the inverter at a rising of the output voltage,

when the transmission power exceeds a limit value larger than the target power during adjustment of the drive frequency by the second control, the control unit being configured to decrease the target power in the first control.

5. The power transfer system according to claim 4, wherein when the transmission power exceeds the limit value during adjustment of the drive frequency by the second control, the control unit is configured to decrease the target power by subtracting a correction amount proportional to an excess amount of the transmission power over the limit value from the target power.

6. The power transfer system according to claim 5, wherein the control unit is configured to decrease the target power by further subtracting a correction amount proportional to an integrated value of the excess amount from the target power.