| 摘要 |
A surge arrester (1) comprising a stack of a plurality of cylindrical surge arrester elements (11) of a metal oxide varistor material, in which the arrester elements are arranged one after the other between two end electrodes (13) in the axial direction of the surge arrester and surrounded by a polymer insulator (12) making contact with the envelope surfaces of the surge arrester elements. Tension rods (14) are arranged in the polymer insulator in order to retain the surge arrester elements and the end electrodes. The polymer insulator is made of a polymer material which under normal operating conditions is resistant to deformation and is arranged with bulges (121) extending in the axial direction of the surge arrester along the length of the entire polymer insulator, the tension rods being arranged in these bulges. Voids (20) are arranged in the polymer insulator between the stack of surge arrester elements and the tension rods, these voids being preferably arranged close to the tension rods arranged in the bulges. The polymer insulator is arranged with notches (122) to enable it to burst in a controlled manner upon an elevated internal pressure. The notches are preferably arranged in the form of weakened points in the polymer insulator. |
