Optimization of Screen Systems of Non-linear Overvoltage Limiters Rated for High Voltage Classes

On the basis of numerical solution achieved for the adjacent problem of multi-parametric optimization, a combination of screening systems was implemented for non-linear voltage supressors rated for high voltage levels of 500 kV and 750 kV, having both polymer and porcelain insulation and with a high ratio of their height to cross section. The finite elements method was used in this optimization problem to calculate the target function, which was implemented using the Comsol MultiPhysics software. Protection devices made on the basis of calculation data were tested applying operating voltages, under monitoring using an infrared camera. This thermovision testing proved a high level of homogeneity of electric field distribution over the length of structures featuring the mentioned combined screening system.