Comparison of lighting strike specific energy calculation between SIST EN 62305-1 standard and IEC TR 60071-4 technical report using Rise-Time and Peak-To-Zero time measured by Lightning Localization System

摘要

A Lightning Localization System (LLS) SCALAR measures different parameters of lightning strikes in real-time such as lightning location, precise lightning strike time, Peak current amplitude, Rise-Time, Peak-To-Zero time and others. Rise-Time and Peak-To-Zero time can be used in lightning strike specific energy calculation, which can be integrated in protection analysis. Up to now those two parameters were not yet analysed and validated by Milan Vidmar electric power research institute, therefore are still rarely included in those analyses. With the aim to include those parameters in protection analysis, validation has been made with specific energy of lightning strike calculation. First step was to obtain lightning strike data measured by LLS SCALAR. Validation process was based on specific energy calculation on two different methods. First method used was based on SIST EN 62305-1 standard and second on IEC TR 60071-4 technical report. Difference between those two methods are in lightning strike current wave shape used for specific energy calculations. Method based on SIST EN 62305-1 standard uses double ramp wave shape. For specific energy calculation were used measured lightning strike Peak current and calculated time to half value from measured Rise-Time and Peak-To-Zero time. On second method based on IEC TR 60071-4 technical report CIGRE Concave wave shape was used. In this case time to half value was a constant, only LLS measured parameter was lightning strike Peak current. Starting hypothesis was that when calculations on both methods agree, both Rise-Time and Peak-To-Zero time can be included in protection analysis. Preliminary calculations confirmed the hypothesis. Results of detailed calculations of lightning strike specific energy on both methods slightly deviate from expected values. Based on results, a conclusion can be made that the validation process described in this paper is not enough to confirm that Rise-Time and Peak-To-Zero time measured by LLS can be included in the protection analysis. Future detailed analysis is needed to include both parameters in such analysis or in any other way to evaluate the protection level of buildings, power plant facilities and power transmission lines.