Lightning-Correlated Faults in Power Distribution Networks

The paper deals with the correlation between lightning and distribution networks faults and/or voltage dips. In particular, the paper presents an application of a method proposed by the authors to correlate lightning events and relays operations based on the integrated use of: (i) data obtained from the Italian lightning location system (CESI-SIRF), (ii) data relevant to the Italian monitoring system of relay operation (CESI-SAM) and (Hi) calculation results obtained by means of an advanced simulation tool for the accurate estimation of lightning- induced voltages on complex power networks (LIOV-EMTP). The correlation algorithm is able to take into account the uncertainty levels associated with the stroke location and peak current estimates provided by lightning location systems. The results obtained by means of LIOV-EMTP are shown to be of fundamental importance to achieve the appropriate estimation of the correlation of interest. A plus of the proposed algorithm is that it can make use, mostly during its validation/tuning phase, also of measured lightning-induced overvoltage waveforms recorded by means of a distributed monitoring system of voltage transients, which has been installed in a portion of the Italian distribution network.