ANALYSIS ON SEASONAL COEFFICIENTS OF GROUNDING SYSTEMS FOR POWER PLANTS AND SUBSTATIONS
Yanqing Gao · Gaoya dianqi · 2003
Seasonal coefficients affect the safety of grounding systems and increase with the thickness and resistivity of the soil layer. The seasonal coefficient of grounding resistance possibly reaches 3.0 in freezing region of North China, and those of touch voltage and step voltage 10 and 5.4, respectively. The raining season will lead to the touch voltage increasing, hence the influence of raining on the safety of grounding system should be considered. Adding vertical rods to grounding system will decrease the seasonal coefficient and stabilize the safety of grounding system.