Capacitor element method for manufacturing a capacitor element and use of a power capacitor

1. A capacitor element for a power capacitor for AC-high voltage, comprising:

a plurality of series-connected cylindrical sub-elements, where each sub-element includes at least two strips of dielectric material wound in a number of turns to provide a winding, and wherein a layer of electrically conductive material is disposed between the turns of said winding, wherein the sub-elements are disposed one outside the other as seen in a direction transversely to a plane of the strips, wherein a strip in an outermost sub-element is longer than each strip in each inwardly lying sub-element.

2. The capacitor element according to claim 1 , wherein each strip in the outermost sub-element has a length in a range of 110% to 120% of a length of each strip in a nearest inwardly lying sub-element.

3. The capacitor element according to claim 1 , wherein the layer of electrically conductive material comprises a coating on at least one side of each strip.

4. The capacitor element according to claim 3 , wherein each sub-element includes two mutually different strips wound in a number of turns, wherein each alternative winding turn is formed with a first of the strips and each other alternate winding turn is formed with a second of the strips.

5. A power capacitor for AC-high voltage, comprising:

a plurality of capacitor elements each comprising a plurality of series-connected cylindrical sub-elements, each sub-element comprising at least two strips of dielectric material wound in a number of turns to provide a winding, a layer of electrically conductive material is disposed between the turns of the winding, wherein the sub-elements are arranged one outside the other as seen in a direction transversely to a plane of the strips, wherein a strip in an outermost sub-element is longer than each strip in each inwardly lying sub-element, said capacitor elements being arranged in juxtaposed relationship along a common axis extending in the longitudinal direction of the cylindrical sub-elements.

6. A capacitor battery, comprising:

at least one power capacitor comprising a plurality of series-connected cylindrical sub-elements, each sub-element comprising at least two strips of dielectric material wound in a number of turns to provide a winding, a layer of electrically conductive material is disposed between the turns of the winding, wherein the sub-elements are arranged one outside the other as seen in a direction transversely to a plane of the strips, wherein a strip in an outermost sub-element is longer than each strip in each inwardly lying sub-element.

7. A method of manufacturing a capacitor element for a power capacitor, wherein the capacitor element includes a plurality of series-connected cylindrical sub-elements, the method comprising:

forming each sub-element by winding at least two strips of dielectric material in a plurality of turns to form a winding,

applying a layer of electrically conductive material between the turns of the winding,

arranging the sub-elements one outside the other as seen in a direction transversely to the plane of the strip, and

winding the outermost sub-element with a strip that is longer than a strip with which each inwardly lying sub-element is wound.

8. The method according to claim 7 , wherein the outermost sub-element is wound with a strip having a length is in a range of 110 to 120% of a length of strips used to wind a nearest inwardly lying sub-element.

9. The method according to claim 7 , wherein the layer of electrically conductive material is applied by coating at least one side of each strip of dielectric material with a coating of electrically conductive material prior to winding said strip.

10. The method according to claim 9 , wherein each sub-element is formed by simultaneously winding two different strips of dielectric material.

11. The method according to claim 7 , further comprising:

utilizing the power capacitor as a component in an electrical system.