FIBER INSULATOR WITH FIBER OPTICAL CABLE

Abstract

A fiber insulator (100) with a fiber optical cable (200) is provided. The fiber insulator (100) comprises a fiber optical cable (200); a ceramic jacket (120), wherein the ceramic jacket (120) is hollow, wherein the ceramic jacket (120) has an inner whole diameter (D) configured to guide the fiber optical cable (200); an insulating filling material (130), which at least partially fills out the ceramic jacket (120) and is arranged between the fiber optical cable (200) and the ceramic jacket (120), wherein the insulating filling material (130) has thermal properties similar to the thermal properties of the fiber optical cable (200) and the ceramic jacket (120), and wherein at least one end of the fiber insulator (100) is closed by at least one end cap (151, 152).

Claims

1. Fiber insulator (100) with a fiber optical cable (200), comprising: a fiber optical cable (200); a ceramic jacket (120), wherein the ceramic jacket (120) is hollow, wherein the ceramic jacket (120) has an inner whole diameter (D) configured to guide the fiber optical cable (200); an insulating filling material (130), which at least partially fills out the ceramic jacket (120) and is arranged between the fiber optical cable (200) and the ceramic jacket (120), and wherein at least one end of the fiber insulator (100) is closed by at least one end cap (151, 152) configured to close the at least one end of the fiber insulator (100), wherein the at least one end cap (151, 152) is configured such that the fiber optical cable (200) passes through the at least one end cap.

2. Fiber insulator (100) according to claim 1, wherein an outer surface of the ceramic jacket (120) has an undulating shape and an inner surface of the ceramic jacket (120) faces the fiber optical cable (200).

3. Fiber insulator (100) according to claim 1 or 2, wherein the insulating filling material (130) has thermal properties configured to compensate thermal properties of at least one of the fiber optical cable (200) and the ceramic jacket (120).

4. Fiber insulator (100) according to any of claims 1 to 3, wherein the at least one end cap (151, 152) is configured to seal the at least one end of the fiber insulator (100), and/or wherein the at least one end cap (151, 152) is configured to fix the fiber optical cable (200) such that movement of the fiber optical cable (200) along a fiber optical cable extension direction is prevented.

5. Fiber insulator (100) according to claim 4, wherein the at least one end cap (151, 152) has a fiber optical cable opening, the fiber optical cable opening being arranged such that the fiber optical cable (200) passes through the fiber optical cable opening into the fiber insulator (100), wherein, as an option, the fiber optical cable opening is configured to seal with the fiber optical cable (200) when the fiber optical cable (200) passes through the fiber optical cable opening.

6. Fiber insulator (100) according to any of claims 1 to 5, wherein the at least one end of the fiber insulator (100) has a square like form when viewed in a cross section extending along an extension direction of the fiber insulator (100), wherein, when viewed in the cross section, the square like form has a front surface and a rear surface parallel to the front surface and said front and rear surfaces being connected by side surfaces, wherein the fiber insulator (100) extends from the front surface of the square like form along the extension direction, wherein, when viewed in the cross section, the front and rear surfaces of the square like form extend along a direction perpendicular to the extension direction, and wherein at least one edge formed by one of the side surfaces and the front surface or the rear surface is configured as an opening (141, 142) arranged to receive the at least one end cap (151, 152), wherein, as an option, the opening (141, 142) of the square like form seals with the at least one end cap (151, 152).

7. Fiber insulator (100) according to claim 6, wherein at least two edges of the square like form are configured as openings (141, 142) configured to receive at least one respective end cap (151, 152).

8. Fiber insulator (100) according to claim 7, wherein, when viewed in the cross-section, the at least two openings (141, 142) of the square like form are formed at the edges corresponding to the side surfaces connecting to the front surface.

9. Fiber insulator (100) according to any of the preceding claims, wherein the fiber optical cable (200) comprises: a hollow tube (210) extending along the fiber cable extension direction; at least one fiber (220) extending along the fiber cable extension direction and arranged within the hollow tube (210); and a special gel (230) arranged in the hollow tube (210) and at least partially between the at least one fiber (220) and the hollow tube (210), wherein the hollow tube (210) has at least a first section (211) and a second section (212), wherein the first section (211) of the hollow tube (210) is arranged inside the fiber insulator and the second section (212) is arranged outside the fiber insulator, the second section (212) extending from the at least one end cap away from the at least one end cap along the fiber cable extension direction, wherein an outer surface of the second section (212) of the hollow tube (210) is covered by a high resistant aramid yarn (240), wherein an outer surface of the high resistant aramid yarn (240) is covered by a polyurethane, polyethylene or cross-linked polyethylene/flame retardant non-corrosive jacket (250).

10. Fiber insulator (100) according to claim 9, wherein the fiber optical cable opening is configured to fix the second section of the hollow tube (210).

11. Fiber insulator (100) according to claim 9 or 10, wherein the fiber optical cable opening is configured to be fixed with the high resistant aramid yarn and/or the non-corrosive jacket (250).

12. Fiber insulator (100) according to any of claims 9 to 11, wherein the special gel (230) has a specific velocity configured to only partially transmit movement and/or rotation of the hollow tube (210) to the at least one fiber (220) or wherein the special velocity is configured to decouple movement and/or the rotation of the hollow tube (210) from movement of the at least one fiber (220), and/or wherein the special gel (230) has the specific viscosity configured to not move or drip out at the fiber optical cable ends even if the fiber optical cable (200) is arranged in a position in which the fiber optical cable (200) extends in a fiber optical cable extension direction parallel to the earth's gravitational pull.

13. Fiber insulator (100) according to any of claims 9 to 12, wherein the hollow tube (210) is made of a dual layer hollow tube, the dual layers being polycarbonate and polybutylene terephthalate, or wherein the hollow tube (210) is made of polyamide, ethylene tetrafluoroethylene or polybutylene terephthalate.

14. Fiber insulator (100) according to any of claims 9 to 13, wherein the hollow tube (210) is a loose hollow tube.

Description

[0057] FIG. 1 a cross sectional view of a fiber insulator according to the present invention;

[0058] FIG. 2 a cross sectional view of a fiber optical cable according to the present invention; and

[0059] FIG. 3 a cross sectional view, a side view and a top view of an example application of the fiber insulator and the fiber optical cable.

[0060] The following description of the drawings serves explanation purposes and should not be construed as limiting the claims and scope of the invention to specific details thereof. Furthermore, the measurements and sizes of the figures do not necessarily have to correspond to reality and are drawn for explanation purposes.

[0061] FIG. 1 shows a cross sectional view of a fiber insulator 100 according to the present invention. The cross sectional view extends in the drawing plane. The fiber insulator 100 comprises a fiber optical cable 200, a ceramic jacket 120 and an insulating filling material 130. The fiber optical cable has the reference sign 200 in FIG. 1, however, the fiber optical cable 200 in FIG. 1 may have a different configuration than the fiber optical cable illustrated in FIG. 2. Of course, the fiber optical cable may be the fiber optical cable 200 described with reference to FIG. 2.

[0062] The ceramic jacket 120 is hollow and has an inner whole diameter D configured to guide the fiber optical cable 200 along an extension direction of the fiber insulator 100 or the fiber optical cable 200. As apparent from FIG. 1, the diameter D of the ceramic jacket 120 is set to be greater than a diameter of the fiber optical cable 200 to allow the fiber optical cable 200 to be fed through the fiber insulator 100. In particular, the diameter D of the ceramic jacket 120 is set such that insulating filling material 130 can be filled into the hollow ceramic jacket 120 and be arranged between the fiber optical cable 200 and the ceramic jacket 120. The insulating material 130 is electrically insulating. The insulating filling material 130 has thermal properties configured to compensate thermal properties of at least one of the fiber optical cable 200 and the ceramic jacket 120. That is, the thermal properties of the insulating material 130 are set/configured such that it can compensate, e.g., heat transferred or absorbed by the ceramic jacket 120, which is not transmitted to the fiber optical cable 200. In other words, the thermal properties of the insulating material 130 can be configured to be temperature isolating.

[0063] The insulating filling material 130 may be a material which can be firstly provided in a fluid or gel like condition for being filled into the ceramic jacket 120. Once the fiber optical cable 200 and the insulating filling material 130 are provided inside the ceramic jacket 120, the insulating filling material 130 can harden and become a long term stable, electrically and temperature insulating part of the fiber insulator 100. Moreover, at least one end of the fiber insulator 100 is closed by at least one end cap 151, 152.

[0064] By providing the insulating filling material 130 at least partially inside the ceramic jacket 120 and at least partially arranged between the fiber optical cable 200 and the ceramic jacket 120, the insulating performance of the fiber insulator 100 is improved and any optical signals transmitted via the fiber optical cable 200 can be shielded against disruptive environmental influences, such as high voltage environments.

[0065] As apparent from FIG. 1, an outer surface of the ceramic jacket 120 has an undulating shape and an inner surface of the ceramic jacket 120 faces the fiber optical cable 200. In particular, the inner surface of the ceramic jacket 120 has a smooth surface to allow a simplified feeding through of the fiber optical cable 200 and an improved filling process of the insulating filling material 130. This provides an increased creepage distance compared to a smooth outer surface (smooth rob), wherein the longer creepage distance contributes to the insulation level of the insulator 100.

[0066] Furthermore, as apparent from FIG. 1, the fiber optical cable 200 or an hollow tube 210 thereof has a first section 211 and a second section 212. The first section 211 is arranged within/inside the fiber insulator 100, in particular, within the ceramic jacket 120. The second section 212 is arranged outside the fiber insulator 200. As illustrated in FIG. 1, the second section 212 extends from the at least one end cap 151 along the extension direction of the fiber optical cable 200 to the bottom part of FIG. 1. Thus, the second section 212 extends away from the at least one end cap 151.

[0067] In FIG. 1, the second section 212 extends from an outer surface of the at least one end cap 151. The first section 211 extends at least from an inner surface opposite the outer surface of the at least one end cap 151 along the inside of the ceramic jacket 120.

[0068] FIG. 1 only shows a bottom part of the fiber insulator 100 and a corresponding bottom end thereof. Of course, the fiber insulator 100 can have a top part also having an end of the fiber insulator 100 which may be identically configured to the bottom end illustrated in FIG. 1.

[0069] The at least one end of the fiber insulator 100 has a square like form in FIG. 1. In particular, FIG. 1 shows a rectangular form of the at least one end of the fiber insulator 100. Said square like form is hollow and is connected to the inner space of the hollow ceramic jacket 120. Moreover, the square like form has a front surface, a rear surface and two side surfaces in the cross section view of FIG. 1. Of course, when seen in a three dimensional manner, at least four side surfaces are provided. The front and rear surface are connected by the two side surfaces to form the square like form. In addition, the front and rear surface of the square like form extend perpendicular to the extension direction of the fiber insulator 100. As apparent from FIG. 1, the front and rear surfaces of the square like form extend beyond the undulating shape of the ceramic jacket 120.

[0070] Furthermore, the square like form has two openings 141, 142 formed at the lower corners/edges of the square like form when viewed in FIG. 1. Each of the openings 141, 142 may be provided with an end cap 151, 152. The end caps 151, 152 may be configured to close, and as an option, seal the openings 141, 142 to protect the insulating filling material 130 as well as making the filling process possible. The fiber optical cable 200 passes through a fiber optical cable opening of the end cap 151. The configuration of the fiber insulator according to FIG. 1 allows a simple and time efficient construction of the fiber insulator 100. That is, the fiber optical cable 200 can be fed through the fiber optical cable opening of the end cap 151 and can thus be arranged within the fiber insulator 100 in an easy manner. Namely, it is easy to pass the fiber optical cable 200 through the end cap 151 and pull it through the fiber insulator 100, while the end cap 151 maintains its position at the opening 141 during pulling of the fiber optical cable. Secondly, the other opening 142 can be used before or after arrangement of the fiber optical cable 200 for filling in the insulating filling material 130. Since the opening 142 can have a greater diameter than the fiber optical cable 200 and can still be sealed or closed by the end cap 152, an efficient filling process is achieved. Also the openings 141, 142 are connected to the inner whole space of the square like form to enable the optical cable 200 to pass through it and to allow introduction of the insulating filling material 130.

[0071] The end caps 151, 152 can be configured to seal the openings 141, 142 with or without the fiber optical cable 200.

[0072] The at least one end cap 151, 152 may be configured as a plug to close the at least one end of the fiber insulator 100. In particular, the at least one end cap 151, 152 may have a disc or plug like shape with a radius corresponding to or slightly smaller than a radius of the opening 141, 142.

[0073] FIG. 2 shows a cross sectional view of a fiber optical cable 200 according to the present invention. The cross sectional view of FIG. 2 is perpendicular to the cross sectional view of FIG. 1 and is a cross section view of the fiber optical cable 200 at the second section 211. The fiber optical cable 200 comprises a hollow tube 210 extending along a fiber cable extension direction as previously presented with respect to FIG. 1. The fiber optical cable 200 further comprises at least one fiber 220 extending along the fiber cable extension direction, wherein the at least one fiber 220 is arranged within the hollow tube 210. There may be provided two or more fibers 220 inside the hollow tube 210. Moreover, a special gel 230 is arranged in the hollow tube 210 and at least partially between the at least one fiber 220 and the hollow tube 210. An outer surface of the second section 211 of the hollow tube 210 is covered by a high resistance aramid yarn 240, wherein an inner surface of the hollow tube 210 faces the at least one fiber 220. Moreover, an outer surface of the high resistant aramid yarn 240 is covered by a polyurethane, polyethylene or cross-linked polyethylene/flame retardant non-corrosive jacket 250.

[0074] By arranging the special gel 230 inside the hollow tube 210 and, in particular, between the fiber optical cable 200 and the inner surface of the hollow tube 210, it is possible to attenuate any movement of the hollow tube 210 such that less movement or even no movement is transmitted via the special gel 230 to the at least one fiber 220. In other words, due to the velocity of the special gel 230, it is possible to decouple or attenuate any movement of the hollow tube 210 from movement of at least one fiber 220. This is beneficial since any small movement or vibration applied to the at least one fiber 220 may have an impact on a transmitted optical signal and may deteriorate the optical signal. By reducing said impact or even eliminating the impact, it is possible to perform highly sensitive measurements and transmitting corresponding optical signals via the fiber optical cable 200 without or less deteriorated reception at a corresponding measurement station.

[0075] In particular, the velocity of the special gel 230 can be configured or set to a velocity to only partially transmit movement and/or rotation of the hollow tube to the at least one fiber 220. Moreover, the special gel 230 has the velocity configured to not more or drip out at the fiber optical cable ends even if the fiber optical cable 200 is arranged in a position in which the fiber optical cable 200 extends in a fiber optical cable extension direction parallel to the earth's gravitational pull.

[0076] The hollow tube 210 can be made of a dual layer hollow tube, wherein the dual layers are polycarbonate and polybutylene terephthalate. Alternatively, the hollow tube 210 can be made of polyamide, ethylene tetrafluoroethylene or polybutylene terephthalate. For a moderate environment such as in Europe, a polybutylene terephthalate could be used.

[0077] Moreover, the hollow tube 210 can be configured as a loose hollow tube. That means, the hollow tube 210 is not tensioned between the two ends of the fiber optical cable, but may rest in a loose configuration. This is further beneficial for attenuating movement of the fiber optical cable 200.

[0078] Now, with reference to FIG. 1 again, the second section 211 of the fiber optical cable 200 being comprised of the hollow tube 210, the at least one fiber 220, the special gel 230, the high resistant aramid yarn 240 and the non-corrosive jacket 250 is fixed to the at least one end cap 151. In particular, at least the high resistant aramid yarn 240 and the non-corrosive jacket 250 are fixed to the at least one end cap 151.

[0079] By fixing only the high resistant aramid yarn 240 and the non-corrosive jacket 250, while the hollow tube 210 can be regarded as a loose tube, for example a pull force applied to the fiber optical cable 200 applies to the high resistant aramid yarn 240 and the non-corrosive jacket 250 and not the loose tube, in particular, not the fiber 220. The pull force is directed to the at least one end cap 151 and may be to the fiber insulator 100. Accordingly, the fiber 220 is protected from external forces applied to the fiber optical cable 200 increasing the shelf life of the fiber optical cable 200 as well as protecting the transmission properties of the fiber 220, which would otherwise decrease or be deteriorated.

[0080] FIG. 3 shows three different views, namely a cross sectional view, a side view and a top view of an example application of the present invention. At the cross sectional view, the fiber insulator 100 according to FIG. 1 is shown with the fiber optical cable 200. The side view shows the fiber insulator 100 with an arm 320 of a Breaking-closing disconnecting switch (BCDS) arranged at an upper end of the fiber insulator 100. The fiber optical cable 200 is connected to a measurement station 310 and passes through a lower end of the fiber insulator 100. The optical fiber cable 200 is guided by the fiber insulator 100 to the upper end and is fed through the arm 320 to an optical measurement position. Moreover, as exemplarily illustrated in the side view, at the environment at the upper end of the fiber insulator 100, a voltage of V1 is applied where the optical measurement position is. In addition, a voltage V2 is present in the environment at the lower end. The differences between the voltages V1 and V2 may be between 50 kV to 250 kV. As exemplarily illustrated in the side view, a turn arrow T is shown, see also the top view. It may be necessary for such an optical measurement to move or turn the arm 320 to another measurement or off position. If the arm 320 is turned as illustrated by the arrow T, the torsion is also applied to the fiber optical cable 200. It was already explained above that the optical signals transmitted via the fiber optical cable 200 can be very sensitive and thus such a torsion would deteriorate the optical signal. Since the optical fiber cable 200 can be configured as the optical fiber cable 200, it is possible to reduce the deteriorating effect of the torsion via the special gel 230. Accordingly, it is possible to move the optical measurement arrangement with the fiber insulator 100 and the fiber optical cable 200 without having a deteriorated optical signal.