Controlled pre-charge circuit arrangement

Patent metadata

Field	Value
Publication number	US-10549643-B2
Application number	US-201615232554-A
Country	US
Kind code	B2
Filing date	Aug 9, 2016
Priority date	Aug 9, 2016
Publication date	Feb 4, 2020
Grant date	Feb 4, 2020

Abstract

A vehicle system includes a relay and coil of a contactor. The relay is configured to transfer current between a traction battery and an electrical load when closed. The system also includes a controller configured to operate a switch such that current flow from the traction battery through the coil and switch, and bypassing the relay, causes the relay to close to permit pre-charging of the load.

First claim

What is claimed is:

1. A vehicle system comprising:
a contactor including a relay and coil, the relay configured to transfer current between a traction battery and an electrical load when closed; and
a controller configured to operate a switch such that current flow from the traction battery through the coil and switch, and bypassing the relay, causes the relay to close to permit pre-charging of the load.

2. The system of claim 1 , wherein the relay and coil are connected in series and define a pre-charge contactor configured to open responsive to pre-charge completion.

3. The system of claim 1 , wherein the relay and coil define a main contactor configured to remain closed responsive to pre-charge completion.

4. The system of claim 1 , wherein the controller is further configured to operate the switch such that the causing of the relay to close permits pre-charging of the load to a first threshold, and to subsequently operate the switch to permit pre-charging of the load to a second threshold.

5. The system of claim 4 , wherein the second threshold is greater than the first threshold.

6. The system of claim 4 , wherein the first threshold corresponds to a voltage measured across a relay bypass path and wherein the second threshold corresponds to a voltage measured across the battery.

7. The system of claim 6 , wherein pre-charging the load to a voltage measured across the battery is indicative of pre-charge completion.

8. The system of claim 1 further comprising a resistor connected with the relay and coil such that amount of current bypassing the relay is greater than a pull-in current that causes the relay to close and less than an upper-bound current that causes a temperature of the coil to exceed a predefined value.

9. A system for a traction battery comprising:
a contactor including a coil and relay connected in series, the relay configured to close in response to a magnitude of current through the coil being greater than a first threshold; and
a controller configured to, responsive to a pre-charge request, enable current from the battery to flow through the coil and bypass the relay such that a magnitude of the current from the battery is less than a second threshold greater than the first prior to the relay closing to pre-charge an electrical load.

10. The system of claim 9 , wherein pre-charging the load includes causing a voltage of the load to correspond to a voltage across a relay bypass path.

11. The system of claim 9 , wherein the controller is further configured to disable current flow through the coil and relay in response to a voltage of the load corresponding to a voltage of the battery.

12. A method for a traction battery comprising:
in response to receiving a pre-charge request, by a controller, selectively enabling current from the battery to flow through a coil of a contactor and to bypass a relay of the contactor prior to closing of the relay to permit pre-charging of a load to a first threshold voltage.

13. The method of claim 12 further comprising, responsive to the pre-charging of the load to the first threshold voltage, selectively enabling current from the battery to flow through the coil and relay to permit pre-charging of the load to a second threshold voltage greater than the first.

14. The method of claim 13 , wherein the first threshold voltage corresponds to a voltage across a relay bypass path and the second threshold voltage corresponds to a voltage across the battery.

15. The method of claim 14 , wherein the pre-charging the load to a voltage across the battery is indicative of pre-charge completion.

16. The method of claim 12 , wherein the contactor is a pre-charge contactor configured to open in response to pre-charge completion.

17. The method of claim 12 , wherein the contactor is a main contactor configured to remain closed following pre-charge completion to permit transfer of charge between the battery and the load.

Assignees

• Ford Global Tech Llc

Inventors

• Tabatowski-Bush Benjamin A
• Mensah-Brown Arnold Kweku
• Burkman Wesley Edward
• Bolduc Robert

Classifications

• B60L15/2072

  for drive off · CPC title

• H02J50/10

  using inductive coupling · CPC title

• B60L50/51 Primary

  characterised by AC-motors · CPC title

• Y02T10/72

  Electric energy management in electromobility · CPC title

• B60L2270/20

  Inrush current reduction, i.e. avoiding high currents when connecting the battery · CPC title