Voltage detector, malfunction detecting device, contactless power transmitting device, contactless power receiving device, and vehicle

• US 8,907,680 B2
• Filed: 05/27/2010
• Issued: 12/09/2014
• Est. Priority Date: 03/30/2010
• Status: Active Grant

• Current Assignee: Nippon Soken, Inc. (DENSO Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Nippon Soken, Inc. (DENSO Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Sakakibara, Hiroyuki, Ichikawa, Shinji
• Primary Examiner(s): Assouad, Patrick
• Assistant Examiner(s): Brown, Lamarr
• Application Number:
  US13/576,525
• Publication Number:
  US 20130009650A1
• Time in Patent Office: 1,657 Days
• Field of Search: 324/713, 324/546, 324/207.11, 324/207.12, 324/207.15, 324/246, 324/239, 324/243, 324/256, 324/257, 343/732, 343/719, 343/741, 343/742, 320/108, 455/41.1, 455 80- 83, 455/562.1, 455/575.7, 455/107, 455/129
• US Class Current: 324/546
• CPC Class Codes: B60L 2210/10 DC to DC 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 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2240/527 Voltage
• CPC Class Codes: B60L 2240/662 Temperature
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 3/00 Electric devices on electrically-propelled vehicles for safety purposes; Monitoring operating variables, e.g. speed, deceleration or energy consumption methods or circuit arrangements for monitoring or controlling batteries or fuel cells B60L58/00
• CPC Class Codes: B60L 3/0023 Detecting, eliminating, remedying or compensating for drive train abnormalities, e.g. failures within the drive train
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/40 using propulsion power supplied by capacitors
• CPC Class Codes: B60L 50/60 using power supplied by batteries in combination with fuel cells B60L50/75
• 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 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/40 for controlling a combination of batteries and fuel cells
• CPC Class Codes: G01R 31/72 Testing of electric windings testing of transformers G01R31/62
• CPC Class Codes: G06F 12/00 Accessing, addressing or allocating within memory systems or architectures digital input from, or digital output to record carriers, e.g. to disk storage units, G06F3/06
• 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 50/70 : involving the reduction of electric, magnetic or electromagnetic leakage fields
• CPC Class Codes: H02J 50/90 : involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 : Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• 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 7/0048 : Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/007192 : in response to temperature
• CPC Class Codes: H02J 7/02 : for charging batteries from ac mains by converters
• CPC Class Codes: H02M 3/33561 : having more than one ouput with independent control
• 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 90/40 : Application of hydrogen technology to transportation, e.g. using fuel cells

Abstract

A voltage detector for detecting a voltage generated in a second resonant coil that is disposed to face a first resonant coil and that performs at least one of electric power transmission and electric power reception to and from the first resonant coil in a contactless manner by means of electromagnetic resonance includes: a first high-impedance element having one end connected to one end of the second resonant coil; a second high-impedance element having one end connected to the other end of the second resonant coil; a low-impedance element connected between the other end of the first high-impedance element and the other end of the second high-impedance element and having an impedance smaller than each of those of the first and second high-impedance elements; and an output terminal for outputting a signal associated with a voltage applied across the low-impedance element.

Claims

1. A voltage detector for detecting a voltage generated in a second resonant coil that is disposed to face a first resonant coil and that performs at least one of electric power transmission and electric power reception to and from said first resonant coil in a contactless manner by means of electromagnetic resonance, said voltage detector comprising:

a first high-impedance element having one end connected to one end of said second resonant coil;

a second high-impedance element having one end connected to the other end of said second resonant coil;

a low-impedance element connected between the other end of said first high-impedance element and the other end of said second high-impedance element and having an impedance smaller than each of those of said first and second high-impedance elements; and

an output terminal for outputting a signal associated with a voltage applied across said low-impedance element,

said first high-impedance element including a first capacitor, and

said second high-impedance element including a second capacitor.

2. The voltage detector according to claim 1, wherein

each of said first and second capacitors includes

an electrode for achieving connection to said second resonant coil, and

a dielectric member whose length in an electric field direction is larger than that of said electrode in a direction perpendicular to said electric field direction.

3. The voltage detector according to claim 2, wherein the length of said dielectric member in said electric field direction is a length that allows an impedance of said voltage detector to be greater than a predetermined value large enough to have no influence over a resonance state between said first and second resonant coils, said impedance of said voltage detector being generated by connecting said first and second capacitors to said second resonant coil.

4. The voltage detector according to claim 1, wherein capacitances of said first and second capacitors are set to be substantially equal to each other.

5. The voltage detector according to claim 1, wherein:

said low-impedance element is an isolation transformer, and

said isolation transformer includes

a primary coil connected between the respective other ends of said first and second high-impedance elements,

a secondary coil connected to said output terminal, and

a toroidal core around which said primary coil and said secondary coil are wound.

6. The voltage detector according to claim 5, further comprising a shield box for shielding an electromagnetic field generated from said second resonant coil, wherein

said isolation transformer is disposed in said shield box.

7. The voltage detector according to claim 1, wherein:

each of said first and second high-impedance elements includes an electrode for achieving connection to said second resonant coil and

said first and second high-impedance elements and said low-impedance element are arranged such that impedances respectively connected to said electrodes are symmetrical to each other.

8. A malfunction detecting device comprising:

the voltage detector recited in claim 1; and

a malfunction determining unit configured to determine a malfunction in said second resonant coil, based on the signal associated with the voltage and output from said voltage detector.

9. The malfunction detecting device according to claim 8, wherein when said signal associated with the voltage is greater than a reference value, said malfunction determining unit determines that said second resonant coil has a high temperature.

10. The malfunction detecting device according to claim 8, wherein said malfunction determining unit determines whether or not loss in said second resonant coil is increased, based on a comparison between said signal associated with the voltage and a voltage of the electric power supplied to said second resonant coil.

11. The malfunction detecting device according to claim 8, further comprising an alarm outputting unit for outputting an alarm to an operator when the malfunction in said second resonant coil is detected.

12. A contactless power transmitting device for transferring electric power from an power source to a power receiving device in a contactless manner by means of electromagnetic resonance, comprising:

a resonant coil for establishing electromagnetic resonance with said power receiving device;

an electromagnetic induction coil configured to transfer the electric power from said power source to said resonant coil by means of electromagnetic induction;

a voltage detector for detecting a voltage generated in said resonant coil; and

a malfunction determining unit configured to detect a malfunction in said resonant coil based on a signal associated with a voltage and output from said voltage detector,

said voltage detector including

a first high-impedance element having one end connected to one end of said resonant coil,

a second high-impedance element having one end connected to the other end of said resonant coil,

a low-impedance element connected between the other end of said first high-impedance element and the other end of said second high-impedance element and having an impedance smaller than each of those of said first and second high-impedance elements, and

an output terminal for outputting the signal associated with the voltage applied across said low-impedance element,

said first high-impedance element having a first capacitor, and

said second high-impedance element having a second capacitor.

13. A contactless power receiving device for receiving electric power from a power transmitting device in a contactless manner by means of electromagnetic resonance, comprising:

a resonant coil for establishing electromagnetic resonance with said power transmitting device;

an electromagnetic induction coil configured to extract the electric power received by said resonant coil, by means of electromagnetic induction;

a voltage detector for detecting a voltage generated in said resonant coil; and

a malfunction determining unit configured to detect a malfunction in said resonant coil based on a signal associated with the voltage and output from said voltage detector,

said voltage detector including

a first high-impedance element having one end connected to one end of said resonant coil,

a second high-impedance element having one end connected to the other end of said resonant coil,

a low-impedance element connected between the other end of said first high-impedance element and the other end of said second high-impedance element and having an impedance smaller than each of those of said first and second high-impedance elements, and

an output terminal for outputting the signal associated with the voltage applied across said low-impedance element

said first high-impedance element having a first capacitor, and

said second high-impedance element having a second capacitor.

14. A vehicle comprising:

a contactless power receiving device for receiving electric power from a power transmitting device in a contactless manner by means of electromagnetic resonance;

a power storage device capable of being charged using the electric power received by said contactless power receiving device; and

a driving device for generating driving power for traveling of said vehicle using the electric power from said power storage device,

said contactless power receiving device including

a resonant coil for establishing electromagnetic resonance with said power transmitting device,

an electromagnetic induction coil configured to extract electric power received by said resonant coil, by means of electromagnetic induction,

a voltage detector for detecting a voltage generated in said resonant coil, and

a malfunction determining unit configured to detect a malfunction in said resonant coil (110), based on a signal associated with the voltage and output from said voltage detector,

said voltage detector including

a first high-impedance element having one end connected to one end of said resonant coil,

a second high-impedance element having one end connected to the other end of said resonant coil,

a low-impedance element connected between the other end of said first high-impedance element and the other end of said second high-impedance element and having an impedance smaller than each of those of said first and second high-impedance elements, and

an output terminal for outputting the signal associated with the voltage applied across said low-impedance element,

said first high-impedance element having a first capacitor, and

said second high-impedance element having a second capacitor.