System and method for inductive charging with improved efficiency

• US 10,675,982 B2
• Filed: 10/20/2017
• Issued: 06/09/2020
• Est. Priority Date: 03/27/2017
• Status: Active Grant

• Current Assignee: General Electric Company
• Original Assignee: General Electric Company
• Inventors: Fontana, Edward Clark, Catalano, Robert James, Harvey, James Edward
• Primary Examiner(s): Levin, Naum
• Application Number:
  US15/788,971
• Publication Number:
  US 20180272882A1
• Time in Patent Office: 963 Days
• CPC Class Codes: B60L 2210/10 DC to DC converters
• 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 53/302 Cooling of charging equipment
• CPC Class Codes: B60L 53/35 Means for automatic or assisted adjustment of the relative position of charging devices and vehicles
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: B60L 53/60 Monitoring or controlling charging stations
• CPC Class Codes: G05D 1/0212 with means for defining a desired trajectory involving a plurality of land vehicles G05D1/0287
• CPC Class Codes: G05D 1/0225 involving docking at a fixed facility, e.g. base station or loading bay parking aids B62D15/027
• CPC Class Codes: G05D 1/0231 using optical position detecting means position-fixing by using electromagnetic waves other than radio waves, e.g. optical position detecting means G01S5/16
• CPC Class Codes: G05D 1/0246 using a video camera in combination with image processing means
• CPC Class Codes: G06F 21/44 Program or device authentication
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 50/10 using inductive coupling
• CPC Class Codes: H02J 50/12 of the resonant type
• 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 50/90 involving detection or optimisation of position, e.g. alignment
• 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 7/06 using discharge tubes or semiconductor devices
• CPC Class Codes: H02M 3/01 : Resonant DC/DC converters
• CPC Class Codes: H02M 3/158 : including plural semiconductor devices as final control devices for a single load
• CPC Class Codes: H02M 3/33571 : Half-bridge at primary side of an isolation transformer
• 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

Abstract

A charging system for charging an electric vehicle comprises an inductor-inductor-capacitor (LLC) battery charger that includes an isolation transformer having a transformer primary and a transformer secondary, the transformer primary included in an inductive charger station of the charging system and the transformer secondary included in an inductive power receiver of the charging system, with the inductive power receiver positioned on the electric vehicle. The LLC battery charger also includes a magnetizing inductor circuit element and a leakage inductor circuit element integrated into the isolation transformer on the transformer primary. The isolation transformer is constructed such that the transformer primary and the transformer secondary are separable from one another, with a selective engaging and disengaging of the transformer primary and the transformer secondary based on movement of the inductive power receiver on the electric vehicle relative to the inductive charger station.

Claims

1. An inductive charger station for charging an electric vehicle, the inductive charger station comprising:

a docking head including a body covered by an electrically insulating coating, the body including one or more tapered protrusions extending out therefrom; and

a transformer primary that includes one or more transformer cores each having a primary winding wound thereabout, each of the one or more transformer cores positioned within the body and extending into a respective one of the one or more tapered protrusions, the transformer primary configured to provide power to a transformer secondary of an inductive power receiver positioned on an electric vehicle, with a selective engaging and disengaging of the transformer primary and the transformer secondary based on movement of the inducive power receiver on the electric vehicle relative to the inductive charger station;

wherein the transformer primary comprises a pair of transformer cores each having a primary winding wound thereabout, so as to form a transformer pair, and wherein the transformer pair operates in an interleaved fashion.

2. The inductive charger station of claim 1, further comprising:

a magnetizing inductor circuit element and a leakage inductor circuit element integrated into the transformer primary.

3. The inductive charger station of claim 1, wherein the docking head comprises:

a heat sink positioned within the body and mounted to each of the one or more transformer cores on a back side thereof; and

a heat pipe integrated with the heat sink to provide additional cooling capability to the transformer primary.

4. The inductive charger station of claim 1, wherein the electrically insulating coating that covers the one or more tapered protrusions and the one or more transformer cores and primary winding positioned therein causes a separation between the transformer primary and the transformer secondary so as to create a leakage inductance, and wherein the leakage inductor circuit element integrated into the isolation transformer operates to enable usage of the leakage inductance to establish resonance between the transformer primary and the transformer secondary.

5. The inductive charger station of claim 1, wherein the inductive power receiver comprises a housing defining a cavity configured to receive the docking head therein, the housing including one or more receptacles that receive the one or more tapered protrusions of the docking head therein;

and wherein one or more secondary windings of the transformer secondary are positioned about the one or more receptacles such that the primary winding on each of the one or more transformer cores of the transformer primary are positioned in close position to the one or more secondary windings upon positioning of the one or more tapered protrusions within the one or more receptacles.

6. The inductive charger station of claim 5, wherein each of the docking head and the housing of the inductive power receiver include a set of alignment features thereon that collectively form a funnel for motion in a plane parallel to the ground, to align the docking head and the inductive power receiver, the set of alignment features including one or more of flat sections, tapered sections, and radius or funnel surfaces.

7. The inductive charger station of claim 5, wherein the inductive charger station and the inductive power receiver include communications connections thereon operable with one another to provide alignment verification of the docking head with the cavity of inductive power receiver and to provide electric vehicle battery bus voltage and current information, the communications connections comprising one of an optical, infrared, or near-field communications port.

8. The inductive charger station of claim 5, wherein the electrically insulating coating on the one or more protrusions and/or the one or more receptacles comprises an ultra-high molecular weight polyethylene coating and/or wherein the one or more protrusions and/or the one or more receptacles comprises rollers integrated therein, with each of the ultra-high molecular weight polyethylene coating and the rollers reducing friction during alignment and mating of the one or more protrusions with the one or more receptacles.

9. The inductive charger station of claim 1, further comprising:

a base component coupled to the docking head via a post, so as to provide for limited movement of the docking head relative to the base component; and

a pivot member coupled to the base component on an end thereof opposite the docking head, the pivot member configured to rotate the inductive charger station between an upright position that provides for mating of the docking head with the inductive power receiver and a down position that provides for storage of the inductive charger station.

10. The inductive charger station of claim 9, further comprising:

a housing including;

a plurality of bezeled surfaces surrounding an interior cavity, the interior cavity housing the docking head, base component, and pivot member when in the down position; and

a moveable cover positioned over the interior cavity, so as to protect the docking head, base component, and pivot member when in the down position.

11. The inductive charger station of claim 1, further comprising:

an AC-DC power converter coupleable to an AC utility feed circuit breaker panel to receive AC power therefrom and convert the AC power to DC power; and

a DC bus connected to the AC-DC power converter to receive the DC power therefrom;

wherein the inductive charger station is coupled to the DC bus to receive the DC power therefrom.

12. The inductive charger station of claim 11, wherein the AC-DC power converter comprises a 12 kW AC to 400 V DC wall-mounted panel.