Electric vehicle supply equipment with temperature controlled current

• US 9,365,123 B2
• Filed: 03/28/2014
• Issued: 06/14/2016
• Est. Priority Date: 04/09/2010
• Status: Active Grant

• Current Assignee: Webasto Charging Systems, Inc. (Webasto Beteiligungs Verwaltung Gbr)
• Original Assignee: Aerovironment
• Inventors: Flack, Albert Joseph
• Primary Examiner(s): Cavallari, Daniel
• Application Number:
  US14/228,630
• Publication Number:
  US 20140203777A1
• Time in Patent Office: 809 Days
• US Class Current: 1/1
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 53/16 Connectors, e.g. plugs or sockets, specially adapted for charging electric vehicles
• CPC Class Codes: B60L 53/18 Cables specially adapted for charging electric vehicles
• CPC Class Codes: B60L 53/305 Communication interfaces
• CPC Class Codes: B60L 53/60 Monitoring or controlling charging stations
• CPC Class Codes: B60L 53/62 in response to charging parameters, e.g. current, voltage or electrical charge
• CPC Class Codes: B60L 53/66 Data transfer between charging stations and vehicles
• CPC Class Codes: B60L 53/68 Off-site monitoring or control, e.g. remote control
• CPC Class Codes: B60L 58/25 by controlling the electric load
• CPC Class Codes: H02J 7/0042 characterised by the mechanical construction
• CPC Class Codes: H02J 7/0045 concerning the insertion or the connection of the batteries
• CPC Class Codes: H05K 7/00 Constructional details common to different types of electric apparatus casings, cabinets, drawers H05K5/00
• 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
• CPC Class Codes: Y02T 90/167 Systems integrating technologies related to power network operation and communication or information technologies for supporting the interoperability of electric or hybrid vehicles, i.e. smartgrids as interface for battery charging of electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: Y04S 30/12 : Remote or cooperative charging

Abstract

In electric vehicle supply equipment (EVSE), interruption of charging due to overheating is prevented by adjusting the pulse duty cycle on the control pilot conductor communicating the maximum allowed current level to the electric vehicle, the adjustment being performed whenever the EVSE temperature exceeds a predetermined threshold temperature below the maximum operating temperature as a function of the approach of the temperature to the maximum operating temperature.

Claims

1. An electric vehicle supply equipment (EVSE) system for charging an electric vehicle, comprising:

a utility connector for receiving electrical power and containing a first pair of power conductors;

a docking connector containing a second pair of power conductors, said docking connector being engagable with a charging port of an electric vehicle;

a pair of contactors providing an interruptible connection between said first and second pairs of power conductors;

a microprocessor and a memory coupled to said microprocessor, said pair of contactors being controlled by said microprocessor;

a control pilot conductor extending through said docking connector, said microprocessor being capable of controlling voltage on said control pilot conductor;

a pulse generator coupled to said control pilot conductor and having a pulse duty cycle controlled by said microprocessor;

a temperature sensor having an output representative of a present temperature, said output coupled to said microprocessor;

said memory containing;

(a) a nominal pulse duty cycle corresponding to a nominal value of maximum allowable current, (b) a predetermined threshold temperature, and (c) set of program instructions executable by said microprocessor whenever said present temperature exceeds said predetermined threshold temperature to reduce the pulse duty cycle of said pulse generator from said nominal pulse duty cycle to an adjusted pulse duty cycle by a reduction factor that is a function of an increase of said present temperature above said predetermined threshold temperature.

2. The EVSE system of claim 1 wherein said function is a proportional function.

3. The EVSE system of claim 1 wherein said memory further contains a maximum operating temperature.

4. The EVSE system of claim 3 wherein said reduction factor is a function of the closeness of said present temperature to said maximum operating temperature.

5. The EVSE system of claim 3 wherein said predetermined threshold temperature is in a range of 10% to 30% of said maximum operating temperature.

6. An electric vehicle supply equipment (EVSE) system, comprising:

a cable;

a utility connector on said cable for receiving electrical power and containing a first pair of power conductors;

a docking connector on said cable containing a second pair of power conductors, said docking connector being engagable with a charging port of an electric vehicle;

a pair of contactors providing an interruptible connection between said first and second pairs of power conductors;

a microprocessor and a memory coupled to said microprocessor, said pair of contactors being controlled by said microprocessor;

a control pilot conductor extending through said docking connector, said microprocessor being capable of controlling voltage on said control pilot conductor;

a pulse generator coupled to said control pilot conductor and having a pulse duty cycle controlled by said microprocessor;

a temperature sensor having an output representative of a present temperature, said output coupled to said microprocessor;

said memory storing;

(a) a nominal pulse duty cycle corresponding to a nominal value of maximum allowable current, (b) a maximum operating temperature, and a (c) set of program instructions executable by said microprocessor, whenever said present temperature exceeds a predetermined threshold temperature, to reduce the pulse duty cycle of said pulse generator from said nominal pulse duty cycle to an adjusted pulse duty cycle by a reduction factor that is a function of the closeness of said present temperature to said maximum operating temperature.

7. The EVSE system of claim 6 wherein said function is a proportional function.

8. The EVSE system of claim 6 wherein said predetermined threshold temperature is in a range of 10% to 30% of said maximum operating temperature.

9. A method of charging an electric vehicle, comprising:

providing in an electric vehicle supply equipment (EVSE) a utility connector for receiving electrical power and containing a first pair of power conductors, a docking connector containing a second pair of power conductors, said docking connector being engagable with a charging port of an electric vehicle, and a pair of contactors between said first and second pairs of power conductors;

providing a control pilot conductor extending through docking connector;

setting a pulse duty cycle on said control pilot conductor to a nominal pulse duty cycle corresponding to a maximum allowable charging current;

sensing a present temperature in said EVSE;

whenever said present temperature exceeds a predetermined threshold temperature, reducing said pulse duty cycle from said nominal pulse duty cycle to an adjusted pulse duty cycle by a reduction factor that is a function of an increase of said present temperature above said predetermined threshold temperature.

10. The method of claim 9 wherein said function is a proportional function.

11. The method of claim 9 wherein said reduction factor is proportional to the nearness of said present temperature to a maximum operating temperature.

12. The method of claim 11 wherein said predetermined threshold temperature is in a range of 10% to 30% of said maximum operating temperature.