Abstract: A tower arrangement for a wind turbine, including: a guyed tower, cable foundations each including a through-hole, one or more stay cables, each stay cable being anchored at its first end at the tower and being anchored at its second end at one of the cable foundations, and one or more anchoring means for anchoring the second end of each stay cable at the respective cable foundation, wherein each stay cable is guided through a respective through-hole and anchored, with respect to its first end, behind the respective through-hole at its second end using the anchoring means is provided. By having the cable foundations comprising the through-holes, guiding the stay cables through the through-holes and anchoring them behind the through-holes, external connection means such as steel structures poured into the concrete foundation are not required. Thus, the anchoring of the stay cables at the cable foundations is simplified.

Abstract: A tower arrangement for a wind turbine, including: a guyed tower, cable foundations each including a through-hole, one or more stay cables, each stay cable being anchored at its first end at the tower and being anchored at its second end at one of the cable foundations, and one or more anchoring means for anchoring the second end of each stay cable at the respective cable foundation, wherein each stay cable is guided through a respective through-hole and anchored, with respect to its first end, behind the respective through-hole at its second end using the anchoring means is provided. By having the cable foundations comprising the through-holes, guiding the stay cables through the through-holes and anchoring them behind the through-holes, external connection means such as steel structures poured into the concrete foundation are not required. Thus, the anchoring of the stay cables at the cable foundations is simplified.

Abstract: A method for second natural frequency wind turbine tower modification is provided. The method includes the steps of: a) determining the second natural frequency of the wind turbine; b) calculating the anti-node of the second natural frequency to determine the point of the wind turbine tower that suffers the greatest displacement during the second natural vibration mode; c) determining an height of the tower corresponding with the anti-node calculated in b); d) calculating a mass to be placed at the height of the tower to modify the second natural frequency considering that a heavier mass leads to a lower second natural frequency; e) placing the mass calculated in step d) at the height determined in step c).

Abstract: An apparatus for automation of weld seams machining of a wind turbine tower is provided. The apparatus includes an automated arm; a machining tool fixed to the automated arm; a compensator system fixed to the machining tool or being part of the automated arm; a joint visor that identifies and locates the weld seam; and a control unit to coordinate the movement of the machining tool with the compensator system and the joint visor. A method of performing a welded circular seam machining in a wind turbine tower with the apparatus is also provided.

Abstract: Reinforced wind turbine tower (1) formed by a hollow body (2), which comprises in its interior at least one reinforcement structure (3) formed by a series of longitudinal reinforcements (4), where each of said reinforcements (4) has its two opposite ends attached by attachment means to the hollow body inner surface (2) of the tower at points placed on different vertical lines, and where each reinforcement (4) has at least one of its ends attached by attachment means to the end of the other consecutive reinforcement (4) with the same.

Abstract: Reinforced hollow for a wind turbine tower comprising a lower ring (2) that determines an opening (3) for the installation of an access door (not represented) inside the tower (1). The hollow incorporates at least one structural element (4) that is fastened on both sides of the opening (3) of the tower's lower ring (2), providing the rigidness necessary to attach a door and permit the reduction of the thickness of the ring by 10-20%.

Abstract: Reinforced hollow for a wind turbine tower comprising a lower ring (2) that determines an opening (3) for the installation of an access door (not represented) inside the tower (1). The hollow incorporates at least one structural element (4) that is fastened on both sides of the opening (3) of the tower's lower ring (2), providing the rigidness necessary to attach a door and permit the reduction of the thickness of the ring by 10-20%.