Static electric induction apparatus comprising a winding and a sensor system for monitoring the temperature in the winding
The present invention relates to a static electric induction apparatus ( 1 b ) comprising a winding ( 2 ) including a plurality of winding units ( 3 ), at least one first spacer element ( 5 ) arranged between the winding units ( 3 ) and including a first groove ( 18 ) defined in the surface thereof, and a sensor system for monitoring the temperature in the apparatus, wherein the sensor system comprises an elongated and flexible temperature sensing element ( 16 ) disposed in the first groove. The first groove ( 18 ) has a curved part that receives the flexible temperature sensing element which is wound at least one revolution in the first groove ( 18 ). The first groove enters and exits the first spacer element in one and the same end of the first spacer element. The apparatus comprises an elongated second spacer element ( 14 a ) extending in an axial direction on the outside of the winding ( 2 ). The second spacer element ( 14 a ) comprises an elongated second groove ( 22 ) arranged in communication with the first groove, and the flexible temperature sensing element ( 16 ) is disposed in the first and second grooves.
1. A static electric induction apparatus comprising:
a winding including a plurality of winding units, a plurality of first spacer elements arranged above each other, wherein each of the first spacer elements has a first groove defined in the surface thereof,
a sensor system for monitoring the temperature in the apparatus, wherein the sensor system includes an elongated and flexible temperature sensing element disposed in each of the first grooves, the first grooves having a curved part that receive the flexible temperature sensing element which is wound at least one revolution in each of the first grooves, and the first spacer elements extend radially between the winding units and have outer ends facing outwardly from the winding, and the first grooves enter and exit the first spacer elements at the outer end thereof, wherein the static electric induction apparatus includes an elongated second spacer element extending in an axial direction on the outside of the winding, the second spacer element includes an elongated second grooved arranged in communication with the first grooves to allow the flexible temperature sensing element to run between the second groove and the first grooves, and the flexible temperature sensing element is disposed the first grooves of the first spacer elements and in the second groove of the second spacer element.
2. The static electric induction apparatus according to claim 1 , wherein the flexible temperature sensing element is wound a plurality of revolutions in the first groove.
3. The static electric induction apparatus according to claim 1 , wherein the flexible temperature sensing element is wound at least three revolutions in the first groove.
4. The static electric induction apparatus according to claim 2 , wherein the length of the part of the flexible temperature sensing element, which is wound in the first groove is at least 0.15 m, preferably at least 0.4 m, and most preferably at least 1 m.
5. The static electric induction apparatus according to claim 1 , wherein the first groove includes a circular part.
6. The static electric induction apparatus according to claim 1 , wherein the sensor system includes an optic sensor adapted for distributed temperature measuring.
7. The static electric induction apparatus according to claim 6 , wherein the optic sensor is a Raman sensor.
8. The static electric induction apparatus according to claim 1 , wherein the flexible temperature sensing element is a fiber optic cable.
9. The static electric induction apparatus according to claim 1 , wherein the sensor system further comprises: an optic sensor configured to generate a laser pulse passing through the fiber optic cable and to detect when the laser pulse is returned, and an evaluating unit configured to determine the temperature in the winding based on light scattering of the laser pulse and the time difference between the points in time when the laser pulse was generated and when it was returned.
10. The static electric induction apparatus according to claim 1 , wherein the static electric induction apparatus is a transformer.
11. The static electric induction apparatus according to claim 1 , wherein the winding is a disc winding or a helical winding.
12. The static electric induction apparatus according to claim 2 , wherein the flexible temperature sensing element is wound at least three revolutions in the first groove.
13. The static electric induction apparatus according to claim 3 , wherein the length of the part of the flexible temperature sensing element, which is wound in the first groove is at least 0.15 m, preferably at least 0.4 m, and most preferably at least 1 m.
14. The static electric induction apparatus according to claim 2 , wherein the first groove includes a circular part.
15. The static electric induction apparatus according to claim 2 , wherein the sensor system includes an optic sensor adapted for distributed temperature measuring.
16. The static electric induction apparatus according to claim 2 , wherein the flexible temperature sensing element is a fiber optic cable.
17. The static electric induction apparatus according to claim 2 , wherein the static electric induction apparatus is a transformer.
18. The static electric induction apparatus according to claim 2 , wherein the winding is a disc winding or a helical winding.
19. The static electric induction apparatus according to claim 9 , wherein the flexible temperature sensing element is a fiber optic cable.