A low leakage current (Co, Mn, Ta)-SnO2 varistor tailored by doping with chromium for power grids

A SnO2 varistor which was prospected to be used in ultra-high voltages grids as an overvoltage protection element was developed. The SnO2 varistor was doped with Cr to improve the comprehensive electrical properties. The optimal electrical parameters are achieved when the dopant of Cr is 0.05 mol% in this article. The voltage gradient of the varistor with Cr 0.05 mol% dopant is 787 V/mm, the nonlinearity is 50 and the leakage current is 7.8 μA/cm2.