In the forthcoming webinar, we will consider how the grounding resistance varies due to lightning current. This is one of the main problems in the lightning protection. The grounding resistance determines the most essential part of the storm overvoltage, i.e. its resistive component. In order to estimate it, we should know a specific current value of the grounding resistance at a time and the given flowing current value. Traditionally, the main reason for decrease of grounding resistance in lightning current flowing is soil ionization processes. In fact, the main reason is completely different. Spark channels creeping over the soil surface for the distance of several dozen meters occur from the lightning current entry point. Having a high conductivity, they create an effect of multiple decrease in the grounding resistance.
During the webinar, the participants will learn about physical properties of creeping plasma discharges and also learn about:
- the dynamics of the grounding resistance changes in time in various lightning currents;
- how the wavefront and pulse amplitude of the resistive component of storm overvoltage change;
- how to consider the effect of decrease in grounding resistance in pre-design calculations of the lightning protection and avoid certain hazardous effects of creeping discharges.
Date and time: 7 September 2022, 11:00 Moscow time.
Speaker: E. M. Bazelyan, Dr.Sc. (Eng.), professor; Krzhizhanovsky Energy Institute, Moscow.
Cost: free of charge, registration is required.