Removing faults from a self-healing film capacitor

Patent metadata

Field	Value
Publication number	US-9666367-B2
Application number	US-201414572089-A
Country	US
Kind code	B2
Filing date	Dec 16, 2014
Priority date	Dec 16, 2013
Publication date	May 30, 2017
Grant date	May 30, 2017

Abstract

A method for treating a capacitor for healing faults therein includes: applying a voltage between a first electrode and a second electrode of the capacitor to charge the capacitor at a start pressure; and pressurizing a non-conductive fluid surrounding the capacitor to a target pressure while the voltage is applied.

First claim

The invention claimed is:

1. A method for healing faults in a capacitor, the method comprising:
applying a voltage between a first electrode and a second electrode of the capacitor to charge the capacitor at a start pressure; and
pressurizing a non-conductive fluid surrounding the capacitor to a target pressure while the voltage is applied.

2. The method of claim 1 , wherein the start pressure is between 1 bar and 10 bar, and wherein the target pressure is between 250 and 350 times as high as the start pressure.

3. The method of claim 1 , wherein the target pressure is between 50 bar and 1000 bar.

4. The method of claim 1 , wherein the pressurizing of the non-conductive fluid comprises gradually increasing a pressure of the non-conductive fluid from the start pressure to the target pressure, and wherein the pressure of the non-conductive fluid increases at a rate between 10 bar per minute and 1000 bar per minute during the pressurizing.

5. The method of claim 1 , wherein the non-conductive fluid having the start pressure is in communication with an atmospheric air pressure.

6. The method of claim 1 , wherein the voltage has a value between 0.5 and 1.5 of a rated voltage of the capacitor, and wherein after the applying of the voltage, an electric field between the first electrode and the second electrode has a value between 20 V/m and 500 V/m.

7. The method of claim 1 , wherein the capacitor comprises a dielectric layer, wherein the dielectric layer comprises a film having a thickness between 1 m and 20 m, wherein the film comprises propylene, and wherein the dielectric layer further comprises a metal vacuum-deposited on one side of the film, wherein the metal is configured for use as at least one of the first electrode and the second electrode.

8. The method of claim 1 , further comprising:
maintaining the charged capacitor for a predetermined time interval at the target pressure.

9. The method of claim 1 , further comprising:
depressurizing the non-conductive fluid to the start pressure; and
discharging the capacitor.

10. The method of claim 1 , wherein the capacitor is assembled in a power cell, and wherein the non-conductive fluid comprises a dielectric liquid.

11. The method of claim 1 , wherein the capacitor has a capacity between 1 pF and 100000 F.

12. The method of claim 1 , further comprising:
applying opposing forces on the first electrode and the second electrode of the capacitor, wherein the opposing forces are generated by at least one spring.

13. The method of claim 1 , wherein the target pressure is between 100 bar and 500 bar.

14. The method of claim 1 , wherein the target pressure is between 250 bar and 350 bar.

15. The method of claim 4 , wherein the pressure of the non-conductive fluid increases at a rate of between 50 bar per minute and 200 bar per minute during the pressurizing.

16. The method of claim 4 , wherein the pressure of the non-conductive fluid increases at a rate of about 100 bar per minute.

17. The method of claim 1 , wherein the voltage has a value between 300 V and 1500 V, and wherein after the applying of the voltage, an electric field between the first electrode and the second electrode has a value between 100 V/m and 200 V/m.

18. The method of claim 7 wherein the metal comprises aluminum.

19. The method of claim 8 wherein the predetermined time interval is between 0 seconds and 10 minutes.

20. The method of claim 10 , wherein the dielectric liquid comprises an ester-based dielectric liquid MIDEL 7131.

21. An apparatus for healing faults in a capacitor, the apparatus comprising:
a vessel comprising a non-conductive fluid configured for surrounding the capacitor when the capacitor is arranged in the vessel;
a voltage source configured to apply a voltage between a first electrode and a second electrode of the capacitor to charge the capacitor at a start pressure of the non-conductive fluid; and
a pressurizing system configured to pressurize the non-conductive fluid surrounding the capacitor to a target pressure while the voltage is applied.

22. The apparatus of claim 21 , wherein the vessel comprises metal walls, a first electrical connector, and a second electrical connector, wherein the first electrical connector and the second electrical connector are configured to carry the voltage from the voltage source outside the vessel to the first electrode and the second electrode within the vessel.

23. A method of manufacturing a capacitor for use in a pressurized environment, the method comprising:
providing a capacitor;
applying a voltage between a first electrode and a second electrode of the capacitor to charge the capacitor at a start pressure; and
pressurizing a non-conductive fluid surrounding the capacitor to a target pressure while the voltage is applied.

Assignees

• Aarskog Fredrik Gundersen
• Siemens Ag

Inventors

• Aarskog Fredrik Gundersen

Classifications

• H01G4/224

  Housing; Encapsulation · CPC title

• H01G2/10 Primary

  Housing; Encapsulation · CPC title

• H01G4/015 Primary

  Special provisions for self-healing · CPC title