ELECTRIC POWER TRANSMISSION SYSTEM

• US 20150048688A1
• Filed: 12/26/2012
• Published: 02/19/2015
• Est. Priority Date: 03/30/2012
• Status: Abandoned Application

• Current Assignee: Equos Research Co., Ltd. (Aisin Corp.)
• Original Assignee: Equos Research Co., Ltd. (Aisin Corp.)
• Inventors: Yamakawa, Hiroyuki, Ito, Yasuo
• Application Number:
  US14/388,186
• Publication Number:
  US 20150048688A1
• Time in Patent Office: Days
• US Class Current: 307/104
• CPC Class Codes: B60L 2210/14 Boost converters
• CPC Class Codes: B60L 2210/20 AC to AC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2210/40 DC to AC converters
• CPC Class Codes: B60L 2240/527 Voltage
• CPC Class Codes: B60L 2250/12 by confirmation, e.g. of the input
• CPC Class Codes: B60L 2250/16 by display
• CPC Class Codes: B60L 53/12 Inductive energy transfer
• 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 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/65 involving identification of vehicles or their battery types
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/0071 with a programmable schedule
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: H02J 7/02 for charging batteries from ac mains by converters
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• 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
• CPC Class Codes: Y02T 90/16 : Information or communication technologies improving the operation of electric vehicles
• CPC Class Codes: Y02T 90/167 : Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 30/14 : Details associated with the interoperability, e.g. vehicle recognition, authentication, identification or billing

Abstract

An electric power transmission system that properly recognizes, from a coupling coefficient, a positional change between a power transmission antenna and a power receiving antenna and can efficiently transmit electric power. The electric power transmission system includes: an inverter unit that converts DC voltage to AC voltage of predetermined frequency to output; power transmission antenna to which AC voltage is input from the inverter unit; power transmission control unit that controls a voltage value of DC voltage input to the inverter unit, and a frequency of AC voltage output by the inverter unit; and a power receiving antenna that faces the power transmission antenna and is for transmission of electric energy from the power transmission antenna via electromagnetic fields, and current flowing through the inverter unit, wherein, based on current flowing through the inverter unit, a coupling coefficient between the power transmission antenna and the power receiving antenna is calculated.

Claims

1. An electric power transmission system, comprising:

an inverter unit that converts DC voltage to AC voltage of a predetermined frequency to output;

a power transmission antenna to which AC voltage is input from the inverter unit;

a control unit that controls a voltage value of DC voltage input to the inverter unit, and a frequency of AC voltage output by the inverter unit; and

a power receiving antenna that faces the power transmission antenna and is for transmission of electric energy from the power transmission antenna via electromagnetic fields, wherein

based on current flowing through the inverter unit, a coupling coefficient between the power transmission antenna and the power receiving antenna is calculated.

2. The electric power transmission system according to claim 1, comprising:

a table in which a relationship between current flowing through the inverter unit and a coupling coefficient between the power transmission antenna and the power receiving antenna is stored, wherein

the control unit inputs DC voltage of a specific voltage value to the inverter unit, and drives the inverter unit at a specific frequency, and measures the current flowing through the inverter unit, and calculates, from the measured current and the table, the coupling coefficient between the power transmission antenna and the power receiving antenna.

3. The electric power transmission system according to claim 2, wherein

as the specific frequency, a frequency between a frequency that yields maximum transmission efficiency between the power transmission antenna and the power receiving antenna and a frequency that yields minimum transmission efficiency is selected.

4. An electric power transmission system, comprising:

an inverter unit that converts DC voltage to AC voltage of a predetermined frequency to output;

a power transmission antenna to which AC voltage is input from the inverter unit;

a control unit that controls a current value of DC voltage input to the inverter unit, and a frequency of AC voltage output by the inverter unit; and

a power receiving antenna that faces the power transmission antenna and is for transmission of electric energy from the power transmission antenna via electromagnetic fields, wherein

based on voltage of current flowing through the inverter unit, a coupling coefficient between the power transmission antenna and the power receiving antenna is calculated.

5. The electric power transmission system according to claim 4, comprising:

a table in which a relationship between a voltage value of DC voltage input to the inverter unit and a coupling coefficient between the power transmission antenna and the power receiving antenna is stored, wherein

the control unit inputs DC voltage of a specific current value to the inverter unit, and drives the inverter unit at a specific frequency, and measures voltage of current flowing through the inverter unit, and calculates, from the measured voltage and the table, the coupling coefficient between the power transmission antenna and the power receiving antenna.

6. An electric power transmission system, comprising:

an inverter unit that converts DC voltage to AC voltage of a predetermined frequency to output;

a power transmission antenna to which AC voltage is input from the inverter unit;

a control unit that controls voltage and current values of DC voltage input to the inverter unit, and a frequency of AC voltage output by the inverter unit;

a power receiving antenna that faces the power transmission antenna and is for transmission of electric energy from the power transmission antenna via electromagnetic fields; and

a table in which a relationship between a drive frequency of the inverter unit and a coupling coefficient between the power transmission antenna and the power receiving antenna is stored, wherein

based on the drive frequency of the inverter unit, a coupling coefficient between the power transmission antenna and the power receiving antenna is calculated.

7. The electric power transmission system according to claim 6, comprising:

a table in which a relationship between a drive frequency of the inverter unit and a coupling coefficient between the power transmission antenna and the power receiving antenna is stored, wherein

the control unit acquires the drive frequency of the inverter unit when inputting DC voltage of specific voltage and current values to the inverter unit, and calculates, from the acquired frequency and the table, the coupling coefficient between the power transmission antenna and the power receiving antenna.