CONTACTLESS POWER FEEDING APPARATUS AND CONTACTLESS POWER FEEDING METHOD

• US 20130335017A1
• Filed: 01/25/2012
• Published: 12/19/2013
• Est. Priority Date: 01/25/2011
• Status: Active Grant

• Current Assignee: Meidensha Corporation
• Original Assignee: Meidensha Corporation
• Inventors: Morita, Kazunori
• Granted Patent: US 9,096,138 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• 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 53/20 characterised by converters located in the vehicle
• CPC Class Codes: B60L 53/36 by positioning the vehicle
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: H01F 21/02 continuously variable, e.g. variometers
• CPC Class Codes: H01F 29/00 Variable transformers or inductances not covered by group H01F21/00 tap change devices H01H9/0005
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• 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
• CPC Class Codes: Y02T 90/16 Information or communication technologies improving the operation of electric vehicles

Abstract

[Object] To make a high efficiency electric power feeding possible without a wireless communication.

[Means for achieving Object] There is provided an electric power feeding apparatus 100 for feeding a secondary coil 210 of a moving body 200 with an electric power, which comprises a primary coil 140 that is magnetically coupled with the primary coil with the work of resonance of a magnetic field and constructed to supply a high frequency electric power to the secondary coil 210, a high frequency electric power driver 120 that converts, by causing a magnetic field to resonate, the electric power from an alternating-current power supply 110 to a high frequency electric power that can transfer to the moving body 200 and feeds the primary coil 140 with the converted electric power, a calculation device 130 that estimates, from supplying current and voltage of the high frequency electric power driver 120, equivalent circuit parameters of an electric power transfer from the primary coil 140 to the secondary coil 210 upon resonance of the magnetic field, and a control device 150 that estimates, from the equivalent circuit parameters estimated by the calculation device 130, the receiving electric power of the secondary coil 210 and controls the high frequency electric power driver 120 in such a manner as to cause the estimated receiving electric power to show the maximum value.

Claims

1. A contactless power feeding apparatus including a secondary coil magnetically coupled with a primary coil outside of a moving body with the work of resonance of a magnetic field and constructed to receive an electric power from the primary coil, a rectifier for rectifying the electric power received by the secondary coil, a rechargeable power storage battery for storing therein the electric power rectified by the rectifier, an electric motor mounted on the moving body for driving the moving body upon receiving the electric power from the rechargeable power storage battery,

which is characterized in that:

the primary coil is magnetically coupled with the secondary coil with the work of resonance of a magnetic field and constructed to feed the secondary coil with a high frequency electric power;

a high frequency electric power driver is provided for converting the electric power outside of the moving body to a high frequency electric power that can be supplied to the moving body upon resonance of the magnetic field, the converted electric power being supplied to the primary coil;

a calculation means is provided for estimating, from supplying current and voltage of the high frequency electric power driver, equivalent circuit parameters of an electric power transfer from the primary coil to the secondary coil upon resonance of the magnetic field; and

a control means is provided for estimating, from the equivalent circuit parameters estimated by the calculation means, a receiving electric power of the secondary coil and for controlling a frequency of the supplying electric power in a manner to cause the estimated receiving electric power to show the maximum value.

2. A contactless power feeding apparatus as claimed in claim 1, which is further characterized in that the control means estimates, from the equivalent circuit parameters estimated by the calculation means, the receiving electric power of the secondary coil which varies in accordance with the supplying electric power, and controls the frequency of the high frequency electric power driver in such a manner as to cause the estimated receiving electric power to show the maximum value.

3. A contactless power feeding apparatus as claimed in claim 1, which is further characterized in that the control means estimates, from the equivalent circuit parameters estimated by the calculation means, the receiving electric power of the secondary coil in accordance with at least one of the capacitance and inductance of the primary coil, and adjusts a resonant frequency of the primary coil by varying at least one of the capacitance and inductance of the primary coil in such a manner as to cause the estimated receiving electric power to show the maximum value.

4. A contactless power feeding method for feeding an electric power to a moving body in a transportation system, the system including a primary coil provided outside of the moving body, a secondary coil magnetically coupled with the primary coil with the work of resonance of a magnetic field and constructed to receive an electric power from the primary coil, a rectifier for rectifying the electric power received by the secondary coil, a rechargeable power storage battery for storing therein the electric power rectified by the rectifier, an electric motor mounted on the moving body for driving the moving body upon receiving the electric power from the rechargeable power storage battery,

the method being characterized by having:

an electric power supplying step in which a high frequency electric power driver converts the electric power outside of the moving body to a high frequency electric power that can be supplied to the moving body upon resonance of the magnetic field, and feeds the converted high frequency electric power to the primary coil while varying a frequency of the converted high frequency electric power;

an equivalent circuit parameter estimating step in which a calculation means estimates, from the supplying current and voltage of the high frequency electric power driver under operation of the electric power supplying step, equivalent circuit parameters of an electric power transfer between the primary and secondary coils upon resonance of the magnetic field;

a receiving electric power estimating step in which a control means estimates, from the estimated equivalent circuit parameters, a receiving electric power of the secondary coil; and

a controlling step in which the frequency of the supplying electric power is so controlled as to cause the estimated receiving electric power to show the maximum value.

5. A contactless power feeding method as claimed in claim 4, which is further characterized in that:

the receiving electric power estimating step estimates, from the equivalent circuit parameters estimated by the equivalent circuit parameter estimating step, the receiving electric power of the secondary coil in accordance with the supplying electric power; and

the controlling step controls the frequency of the high frequency electric power driver in such a manner as to cause the estimated receiving electric power to show the maximum value.

6. A contactless power feeding method as claimed in claim 4, which is further characterized in that:

the receiving electric power estimating step estimates, from the equivalent circuit parameters estimated by the equivalent circuit parameter estimating step, the receiving electric power of the secondary coil in accordance with at least one of the capacitance and inductance of the primary coil; and

the controlling step adjusts a resonant frequency of the primary coil by varying at least one of the capacitance and inductance of the primary coil in such a manner as to cause the estimated receiving electric power to show the maximum value.