Overview

For a considerable time increasingly refined methods have been used worldwide to measure lightning currents at high towers, HV overhead lines and in lightning trigger stations. Field measuring stations also register the radiated electromagnetic interference fields of lightning discharges. From the results of research, lightning as a source of interference is understood and defined with regard to the present protection problems. It is also possible to simulate lightning currents with their extreme values in the laboratory; this is a prerequisite for testing protective installations, components and devices. Also lightning interference fields can be simulated for the testing of information technology equipment.

Because of such wide ranging basic research and the development of protection concepts, such as the concept of lightning protection zones as organizing principle of an EMC, as well as suitable protective measures and devices against field generated and conducted interference due to lightning discharges, we now have the necessary conditions for protecting systems in such a way that the final risk of failure can be kept extremely low. Thus, it can be guaranteed that the essential infrastructure can be maintained and catastrophes avoided in cases of extraordinary atmospheric threats.

The necessity of standardizing complex EMC-oriented lightning protection measures, containing also so-called surge protection measures, has been realized. The International Electrotechnical Commission (IEC) as well as the European (Cenelec) and national standards committees (DINVDE, VG) produce standards on the following:

• Electromagnetic interference of lightning discharge and its statistical distribution as a basis for the assignment of interferences to...