A tensioning device is provided for a surge arrester having an end fitting and tensioner. The tensioning device has an axial clearance for receiving a tensioner and a region being conically tapered in axial direction to be introduced into a clearance of the end fitting being shaped for a substantially exact fit. The conically tapered region has delimitation walls defining the axial clearance for the tensioner being movable toward a clearance interior. An antifriction layer is applied to the surface of the conically tapered region. A production method for a surge arrester and a corresponding surge arrester are also provided.

The present invention belongs to the technical field of lightning protection of power transmission lines, and in particular, relates to a method for limiting lightning overvoltage of a direct-current power transmission line. By means of using operation date of a line itself, lightning current monitoring data, and parameters of an environment where the line is located, a line dynamic operation function curve and a line lightning-protection performance function curve are both corrected to obtain a more realistic voltage difference, thus achieving reliable protection actions and state sensing of a lightning arrester on the line. An apparatus for limiting a lightning overvoltage of a direct-current power transmission line is further provided in the present invention to cooperate with the implementation of the method.

The present invention belongs to the technical field of lightning protection of power transmission lines, and in particular, relates to a method for limiting lightning overvoltage of a direct-current power transmission line. By means of using operation date of a line itself, lightning current monitoring data, and parameters of an environment where the line is located, a line dynamic operation function curve and a line lightning-protection performance function curve are both corrected to obtain a more realistic voltage difference, thus achieving reliable protection actions and state sensing of a lightning arrester on the line. An apparatus for limiting a lightning overvoltage of a direct-current power transmission line is further provided in the present invention to cooperate with the implementation of the method.