Numerical Analysis of Electromagnetic Field, Heat and Thermal Stress of a Transmission Line Surge Arrester for Lightning Currents

The voltage across a 77-kV-class transmission line surge arrester (TLSA) and the heat in the TLSA have been computed using the finite-difference time-domain (FDTD) method for a lightning current having a magnitude of 50 kA, a risetime of 1 mu s, and a half-peak width of about 100 mu s. The TLSA is represented with series-connected-nine ZnO elements, each of which has a length of 36mm and a diameter of 32 mm. The ZnO element is represented with many 2x2x2mm cubic cells, each of which has a nonlinear resistivity in each of the x-, y-, and z -directions dependent on the electric field in each direction and the temperature in each cell. From the spatial and temporal distributions of FDTD-computed heat in the TLSA, the spatial and temporal distributions of thermal stress in the TLSA have been computed using the finite-element method. (c) 2023 Institute of Electrical Engineer of Japan and Wiley Periodicals LLC.