RESONANCE-TYPE NON-CONTACT POWER SUPPLY SYSTEM

• US 20130063085A1
• Filed: 05/12/2011
• Published: 03/14/2013
• Est. Priority Date: 05/14/2010
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toyota Jidoshokki, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Kabushiki Kaisha Toyota Jidoshokki
• Inventors: Takada, Kazuyoshi, Suzuki, Sadanori, Sakoda, Shimpei, Yamamoto, Yukihiro, Ichikawa, Shinji, Nakamura, Toru
• Granted Patent: US 8,994,326 B2
• Time in Patent Office: Days
• US Class Current: 320/108
• CPC Class Codes: B60L 2210/10 DC to DC converters
• CPC Class Codes: B60L 2210/30 AC to DC converters
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 2260/44 by parameter estimation
• 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 53/124 Detection or removal of foreign bodies
• 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: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 2220/20 Batteries in motive systems, e.g. vehicle, ship, plane
• CPC Class Codes: H02J 50/12 of the resonant type
• CPC Class Codes: H02J 50/60 responsive to the presence of foreign objects, e.g. detection of living beings
• 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 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• 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

Abstract

Movable body equipment is provided with: a secondary-side resonance coil, which receives power from a primary-side resonance coil of power supply equipment; a rectifier, which rectifies the power received by the secondary-side resonance coil; and a secondary battery, to which to which the power rectified by the rectifier is supplied. A resonance-type non-contact power supply system is provided with: state of charge detection units, which detect the state of charge of the secondary battery; and an impedance estimation unit, which estimates an impedance estimation value for the secondary battery on the basis of the state of charge of the secondary battery. When the absolute value of the difference between the impedance estimation value and the current impedance value of the secondary battery exceeds a threshold, a determination unit determines that a foreign body is present between the primary-side resonance coil and the secondary-side resonance coil.

Claims

1. A resonance type non-contact power supply system comprising:

power supply equipment including an AC power source and a primary-side resonance coil, which receives power supply from the AC power source;

movable body equipment including a secondary-side resonance coil, which receives electric power from the primary-side resonance coil, a rectifier, which rectifies electric power received by the secondary-side resonance coil, and a secondary battery, to which electric power rectified by the rectifier is supplied;

a state of charge detecting section for detecting a state of charge of the secondary battery;

an impedance estimating section for obtaining an impedance estimate by estimating an impedance of the secondary battery based on the state of charge of the secondary battery; and

a determining section, which determines that there is a foreign object between the primary-side resonance coil and the secondary-side resonance coil when the absolute value of the difference between the impedance estimate and a current impedance, which is the current value of the impedance of the secondary battery, exceeds a threshold value.

2. The resonance type non-contact power supply system according to claim 1, wherein the movable body equipment is mounted and used in an electric vehicle.

3. The resonance type non-contact power supply system according to claim 1, wherein the determining section obtains the current impedance using data representing the relationship between the impedance of the secondary battery and a charged electric power of the secondary battery, which relationship is obtained in advance through experimentation.

4. The resonance type non-contact power supply system according to claim 1, further comprising an alarm device that is activated when the determining section determines the presence of the foreign object.

5. The resonance type non-contact power supply system according to claim 1, wherein the determining section stops electric power supply from the power supply equipment when the absolute value of the difference between the impedance estimate and the current impedance is greater than a second threshold value, which is greater than the threshold value.