Transformer winding

1. A transformer winding comprising:

at least two axially adjacent winding modules which are hollow and arranged cylindrically around a common winding axis and include an electrical conductor wound in layers; and

a common electrical insulation layer through which the winding modules are enveloped,

wherein the insulation layer has, on a radially outer face, at least one ring-like radial depression or ring-like radial elevation which is salient transversely to the winding axis; and

wherein the common electrical insulation layer has a wound insulation material and a flexible profiled strip, the flexible profiled strip being arranged transversely to the winding axis and wound in partially through the insulation material, thereby forming at least some of the radial ring-like depressions or elevations

wherein at least one ring-like radial depression is arranged between the at least two axially adjacent winding modules; and

wherein a radially outer winding layer of a winding module is shortened axially in comparison with winding layers positioned radially beneath the outer winding layer and a form of the ring-like radial depression is matched to the radially outer winding layer.

2. The transformer winding as claimed in claim 1 , wherein the at least one ring-like radial depression or elevation completely surrounds the transformer winding.

3. The transformer winding as claimed in claim 1 , wherein said transformer winding is arranged on a coil former.

4. The transformer winding as claimed in claim 1 , wherein said transformer winding is delimited at both of its axial end faces by a respective end plate.

5. The transformer winding as claimed in claim 1 , wherein at least two winding modules are galvanically connected to one another radially on the inside.

6. The transformer winding as claimed in claim 5 , wherein said transformer winding includes at least two groups of in each case two winding modules which are galvanically connected to one another radially on the inside.

7. The transformer winding as claimed in claim 2 , wherein said transformer winding is arranged on a coil former.

8. The transformer winding as claimed in claim 2 , wherein said transformer winding is delimited at both of its axial end faces by a respective end plate.

9. The transformer winding as claimed in claim 2 , wherein at least two winding modules are galvanically connected to one another radially on the inside.

10. The transformer winding as claimed in claim 1 , wherein said transformer winding is arranged on a coil former.

11. The transformer winding as claimed in claim 1 , wherein said transformer winding is delimited at both of its axial end faces by a respective end plate.

12. The transformer winding as claimed in claim 1 , wherein at least two winding modules are galvanically connected to one another radially on the inside.

13. The transformer winding as claimed in claim 1 , wherein the wound insulation material is a dry insulation material.

14. The transformer winding as claimed in claim 13 , wherein the wound insulation material is a fiber roving which has been preimpregnated with B-stage resin and which has been heated to a polymerization temperature after the winding operation.

15. The transformer winding as claimed in claim 1 , wherein the flexible profiled strip has a T-shaped profile.

16. The transformer winding as claimed in claim 1 , wherein the flexible profiled strip is formed substantially of a silicone rubber.

17. A transformer comprising:

a transformer core and at least one low-voltage-side and one high-voltage-side transformer winding, wherein the high-voltage-side transformer winding is designed as claimed in claim 1 .