Thermal properties of whole-solid-insulated polymeric ZnO surge arrester

A new type of 220 kV whole-solid-insulation polymeric ZnO surge arrester was developed, in which there is no air gap inside the arrester due to silicone rubber filling all the gaps between the ZnO varistor column and the polymeric housing. The electrical, and therefore thermal, overloading of the ZnO varistors could not cause a flashover inside. So the whole-solid-insulation polymeric surge arresters are of a safety-type design. The thermal dispersion capability of the newly developed polymeric arrester was measured and calculated by a special software based on the finite element method (FEM), which is better than that of a traditional ZnO arrester with a porcelain housing. The thermal stability of the developed 220 kV surge arrester was analyzed by FEM analysis software. The thermal balance diagram and the permitted energy absorption capability were discussed. The thermal stability property of the polymeric housing was measured. There are good agreement between the calculation results and the measurement ones