Electric vehicle supply equipment with temperature controlled current

Patent metadata

Field	Value
Publication number	US-9981563-B2
Application number	US-201615356313-A
Country	US
Kind code	B2
Filing date	Nov 18, 2016
Priority date	Apr 9, 2010
Publication date	May 29, 2018
Grant date	May 29, 2018

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.

First claim

What is claimed is:

1. An electric vehicle supply equipment (EVSE) system for charging an electric vehicle, comprising:
a utility connector comprising a first pair of power conductors;
a docking connector comprising a second pair of power conductors, said docking connector being engagable with a charging port of an electric vehicle;
a pair of contactors between said first and second pairs of power conductors;
a processor and a memory accessible by said processor, said pair of contactors under control of said processor;
a control pilot conductor extending through said docking connector;
a pulse generator coupled to said control pilot conductor and having a pulse duty cycle controlled by said processor;
a temperature sensor having an output representative of a present temperature, said output coupled to said processor;
said memory containing: (a) a nominal pulse duty cycle corresponding to a nominal value of maximum allowable current, (b) a predetermined threshold temperature, said processor programmed to reduce the pulse duty cycle of said pulse generator from said nominal 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. The EVSE system of claim 1 wherein the electric vehicle responds to a change in pulse duty cycle by changing current draw accordingly.

7. An electric vehicle supply equipment (EVSE) system, comprising:
a utility connector comprising a first pair of power conductors;
a docking connector comprising a second pair of power conductors, said docking connector being engageable with a charging port of an electric vehicle;
a pair of contactors between said first and second pairs of power conductors;
a processor and a memory accessible by said processor, said pair of contactors under control of said processor;
a control pilot conductor extending through said docking connector;
a pulse generator coupled to said control pilot conductor and having a pulse duty cycle controlled by said processor;
a temperature sensor having an output representative of a present temperature, said output coupled to said processor;
said memory storing: (a) a nominal pulse duty cycle corresponding to a nominal value of maximum allowable current, (b) a maximum operating temperature, said processor programmed to reduce the pulse duty cycle of said pulse generator from said nominal pulse duty cycle by a reduction factor that is a function of the closeness of said present temperature to said maximum operating temperature, whenever said present temperature exceeds a predetermined threshold temperature.

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

9. The EVSE system of claim 7 wherein said predetermined threshold temperature is in a range of 10% to 30% of said maximum operating temperature.

10. The EVSE system of claim 7 wherein the electric vehicle responds to a change in pulse duty cycle by changing current draw accordingly.

Assignees

• Aerovironment Inc

Inventors

• Flack Albert Joseph

Classifications

• B60L53/66

  Data transfer between charging stations and vehicles · CPC title

• B60L53/68

  Off-site monitoring or control, e.g. remote control · CPC title

• B60L53/62

  in response to charging parameters, e.g. current, voltage or electrical charge · CPC title

• H02J7/751

  concerning the insertion or the connection of the batteries · CPC title

• H02J7/70

  characterised by the mechanical construction · CPC title