Lightning Impulse Breakdown Characteristics of Frozen Soil

The impulse characteristics of frozen soil are the fundament for the lightning protection design of the overhead transmission lines in frozen soil environments. In this paper, the conductivity and lightning impulse breakdown characteristics of the frozen soil were experimentally studied, and those key factors influencing the impulse breakdown characteristics of the frozen soils such as temperature, water content and salinity were analyzed systematically. Comparing with the normal soil, some important conclusions on the impulse breakdown characteristics of the frozen soil were proposed. The electric breakdown process accompanied by a thermal thaw process was proposed to explain the impulse breakdown mechanism of the frozen soil.