Capacitive charge coupling with dual connector assemblies and charging system

• US 5,714,864 A
• Filed: 01/10/1997
• Issued: 02/03/1998
• Est. Priority Date: 01/16/1996
• Status: Expired due to Fees

• Current Assignee: Electro Dynamics, Inc.
• Original Assignee: Electro Dynamics, Inc.
• Inventors: Rose, Jeffrey A., Cates, Joseph A.
• Primary Examiner(s): Wong, Peter S.
• Assistant Examiner(s): TOATLEY, GREGORY J
• Application Number:
  US08/779,749
• Time in Patent Office: 389 Days
• Field of Search: 320/1, 320/2, 320/15, 361/311, 361/313, 361/301.1, 361/303, 439/34, 439/609, 307/109, 445/41
• US Class Current: 320/109
• CPC Class Codes: B60L 53/16 Connectors, e.g. plugs or sockets, specially adapted for charging electric vehicles
• CPC Class Codes: H02J 50/05 using capacitive coupling
• 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 7/0042 characterised by the mechanical construction
• 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 90/14 Plug-in electric vehicles

Abstract

A disengageable electrical capacitive coupling for transmitting high frequency AC electrical current is provided. In an electric vehicle charging system, dual first connectors form the vehicle inlet, and mating dual second connectors form the coupler. A dielectric material, such as barium titanium oxide, is positioned between the connectors to form capacitors. A holder secures the connectors together with the dielectric material in between. The interface formed is sufficient for establishing a highly efficient, compact electrostatic field for transmitting the current. Provision is made in the holder for easily disengaging the connectors once the charging cycle is complete. When utilized as a charging system, the capacitive charge coupling is connected between a high frequency drive unit on the charger side and a DC power conversion unit on the energy storage side, such as in an electric vehicle. In an alternative embodiment, the connectors comprise mating multiple section conductive plates formed of a spring metal core with a flexible dielectric coating, such as polypropylene. Variation of the various parameters of the charge coupling is utilized to enhance the power transfer capability.

Claims

1. A disengageable electrical capacitive coupling for transmitting AC electrical current at relatively high voltage in the range of 250-600 volts from an electric lead to an electric line, comprising:

a first connector for receiving said AC electrical current and being connected to said line;

a second connector connected to said lead for transmitting said AC electrical current to said first connector;

dielectrical material positioned between said first and second connector; and

a holder for securing said connectors together with said dielectric material in between for forming an interface sufficient for establishing a compact electrostatic field, and for disengaging said connectors,

whereby said AC electrical current is efficiently transmitted by said capacitive coupling to said electric line from said electric lead and interrupted upon disengagement.

2. The coupling of claim 1, wherein is provided dual first and second connectors, leads and lines to form a full coupling with alternating oppositely polarized electrical charges for AC current transmission.

3. The coupling of claim 2, wherein the dual first connectors include a conductive terminal element, and a dielectric plate fixed thereto forming the dielectric material of the coupling.

4. The coupling of claim 2, wherein the dual first connectors including a conductive core element and a dielectric coating fixed thereto forming the dielectric material of the coupling.

5. The coupling of claim 3, wherein said dielectric plate is ceramic having a relatively high dielectric constant in the range of 7,000-12,000.

6. The coupling of claim 5, wherein said ceramic plate is formed of barium titanium oxide (BaTiO₃).

7. The coupling of claim 6, wherein the ceramic plate has a thickness in the range of between 0.007-0.045 inch.

8. The coupling of claim 2, wherein the dual second connectors include a deformable conductor for mating with the first connectors.

9. The coupling of claim 8, wherein the deformable conductors are comprised of a flexible silicone rubber stretched over a foam base and having a convex operative surface for mating with the first connectors.

10. The coupling of claim 2, wherein said first and second connectors, leads and lines form a charge coupling for an electric vehicle, said first connectors being positioned in the inlet of the electric vehicle and the second connectors forming the coupler for engagement and disengagement of the coupling.

11. A charging system for a direct current energy storage device comprising:

an alternating current power source;

a high frequency drive unit for transmitting AC electrical current from the power source at relatively high voltage in the range of 250-600 volts;

a DC power conversion unit to rectify and regulate the DC electrical current for charging the energy storage device; and

a disengageable capacitive charge coupling between said drive unit and said conversion unit,

whereby the charging current is efficiently transferred by said capacitive coupling to said energy storage device.

12. The charging system of claim 11, wherein said coupling includes dual first and second connectors, a dielectric material, and a holder for securing each first and second connectors together with the dielectric material between, and for disengaging said connectors;

whereby an interface sufficient for establishing a compact electrostatic field is established for transmitting said AC electrical current.

13. The charging system of claim 12, wherein said dielectric material is a barium titanium oxide (BaTiO₃) ceramic plate fixed to each of said first connectors.

14. The charging system of claim 13, wherein said second connectors comprise a deformable conductor to mate with the ceramic plate of the corresponding first connectors.

15. The charging system of claim 12, wherein said holder includes a housing in which said first connectors are positioned;

a slide in which said second connectors are positioned adapted for telescoping movement into said housing for aligning the corresponding first and second connectors;

a toggle linkage mechanism for moving the mating connectors together in a pressure relationship;

a handle on the coupler for engaging and disengaging the connectors through operation of the toggle mechanism; and

a latch for securing the slide within the housing and operated by said handle.

16. A disengageable capacitive charge coupling for use in transmitted high frequency AC electrical current at relatively high voltage in the range of 250-600 volts from a power source to a DC current rectifier and energy storage device comprising:

a first connector having a multiple section conductive plate connected to said rectifier and storage device receiving said AC electrical current;

a second connector having a mating multiple section conductive plate connected to said power source for transmitting said electrical current;

dielectric material between said first and second connectors;

an interdigitator for said plates; and

a holder for securing said plates together forming an interface sufficient for establishing a compact electrostatic field and for disengaging said plates,

whereby said AC charging current is efficiently transmitted by said capacitive charge coupling to said DC energy storage device from said power source and interrupted upon disengagement.

17. The capacitive charge coupling of claim 16, wherein is provided dual first and second connectors with the multiple section conductive plates being fan folded and adapted for mating together to form the coupling;

said dielectric material being formed as a coating on both sides of said plates.

18. The capacitive charge coupling of claim 17, wherein said plates are thin, spring metal for opening by spring memory and said coating comprises polypropylene.

19. The charge coupling of claim 18, wherein said plates include flexible junctures between the sections that nest together and provide the spring memory for opening said plates.

20. The charge coupling of claim 17, wherein said first connectors form an inlet of an electric vehicle having an energy storage device for charging, and wherein said second connectors form a coupler for receipt within the inlet for charging said energy storage device of said vehicle.