Inferring the Correlation Between Lightning Events and Voltage Dips in Distribution Networks

To appropriately infer the correlation between lightning events and flashovers/voltage dips on real distribution networks, data coming from lightning location systems are certainly needed, but need to complemented on the one hand by data coming from distributed measurement systems able to record both protection manoeuvres and lightning-originated transients, and on the other hand by accurate calculation results. Additionally, the analysis needs to be performed on a statistical basis. The paper illustrates the main concepts used in developing a procedure aimed at inferring the above mentioned correlation, which is based on the integrated use of experimental data obtained from the Italian lightning location system CESI-SIRF, a monitoring system of relay operation, a distributed monitoring system of lightning-induced transients and of calculations performed using the LIOV-EMTP code. The application of the procedure to the portion of a real distribution network located in Italy in a high level keraunic area is presented by making use of some CESI-SIRF-detected events.