Transformer arrangement

• US 8,217,744 B2
• Filed: 02/20/2008
• Issued: 07/10/2012
• Est. Priority Date: 03/07/2007
• Status: Expired due to Fees

• Current Assignee: Hexaformer AB
• Original Assignee: Hexaformer AB
• Inventors: Fälldin, Agne, Grivans, Fredrik
• Primary Examiner(s): MAI, ANH T
• Application Number:
  US12/527,461
• Publication Number:
  US 20100295645A1
• Time in Patent Office: 1,602 Days
• Field of Search: None
• US Class Current: 336/10
• CPC Class Codes: H02H 9/08 Limitation or suppression of earth fault currents, e.g. Petersen coil

Abstract

A transformer arrangement comprising a transformer having a neutral and formed as a symmetrical transformer, in particular a cage transformer and having a reactor coil connected to the neutral of the transformer is provided. The transformer can be of any type having a neutral such as a Y-n/Y-n, Z-n/Z-n, Y-n/Z-n or a Z-n/Y-n transformer. By providing a transformer having symmetrical phases connected to a reactor coil a transformer arrangement having less weight is obtained. The lower weight is obtained because in comparison to using an E core for the transformer all phases will be symmetrical so that if a ground fault occurs in one of then phases there is no need for any compensatory windings regardless of which phase suffers the ground fault.

Claims

1. A transformer arrangement comprising a transformer having a neutral, the neutral being connected to a first terminal of a reactor and a second terminal of the reactor being adapted for connection to ground, wherein the transformer is symmetrical.

2. The transformer arrangement according to claim 1 when both the transformer and the reactor have a generally triangular shape as seen from one direction wherein the transformer and the reactor are located closely together having their triangularly shaped sides facing each other.

3. The transformer arrangement according to claim 1, wherein the transformer is connected as a Y-n/Y-n, or a Z-n/Z-n, or a Y-n/Z-n or a Z-n/Y-n transformer.

4. The transformer arrangement according to claim 3, wherein the transformer has a generally triangular shape as seen from one direction.

5. The transformer arrangement according to claim 3, wherein the reactor has a generally triangular shape as seen from one direction.

6. The transformer arrangement according to claim 3, wherein when both the transformer and the reactor a generally triangular shape as seen from one direction, the transformer and the reactor are located closely together having their triangularly shaped sides facing each other.

7. The transformer arrangement according to claim 1, wherein the transformer is a cage transformer.

8. The transformer arrangement according to claim 7, wherein the transformer has a generally triangular shape as seen from one direction.

9. The transformer arrangement according to claim 7, wherein the transformer is connected as a Y-n/Y-n, or a Z-n/Z-n, or a Y-n/Z-n or a Z-n/Y-n transformer.

10. The transformer arrangement according to claim 7, wherein the reactor has a generally triangular shape as seen from one direction.

11. The transformer arrangement according to claim 7, wherein when both the transformer and the reactor a generally triangular shape as seen from one direction, the transformer and the reactor are located closely together having their triangularly shaped sides facing each other.

12. The transformer arrangement according to claim 1, wherein the transformer has a generally triangular shape as seen from one direction.

13. The transformer arrangement according to claim 12, wherein the reactor has a generally triangular shape as seen from one direction.

14. The transformer arrangement according to claim 12, wherein when both the transformer and the reactor a generally triangular shape as seen from one direction, the transformer and the reactor are located closely together having their triangularly shaped sides facing each other.

15. The transformer arrangement according to claim 1, wherein the reactor has a generally triangular shape as seen from one direction.

16. The transformer arrangement according to claim 15, wherein when both the transformer and the reactor a generally triangular shape as seen from one direction, the transformer and the reactor are located closely together having their triangularly shaped sides facing each other.