High field strength varistor material
AssigneeABB Technology AG
InventorsFelix GREUTER, Michael HAGEMEISTER, Oliver BECK, Ragnar OSTERLUND, Reto KESSLER
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Abstract
The present invention relates to a varistor material for a surge arrester with target switching field strength ranging from 250 to 400 V/mm comprising ZnO forming a ZnO phase and Bi expressed as Bi2O3 forming an intergranular bismuth oxide phase, said varistor material further comprising a spinel phase, characterized in that the amount of a pyrochlore phase comprised in the varistor material is such, that the ratio of the pyrochlore phase to the spinel phase is less than 0.15:1.
Claims11
A varistor material for a surge arrester comprising ZnO forming a ZnO phase and Bi expressed as Bi2O3 forming an intergranular bismuth oxide phase, said varistor material further comprising a spinel phase, wherein the amount of a pyrochlore phase comprised in the varistor material is such, that the ratio of the pyrochlore phase to the spinel phase is less than 0.15:1.
Dependencies are inferred from the claim text.