Modeling of lightning surge protection in branched cable distribution network

A general-purpose computer simulation program was developed to model the behavior of voltage surges traveling on power cable networks with multiple branches. The program is capable of displaying the location and magnitude of the maximum surge voltage seen by the cable. It is also capable of reproducing the voltage variations at any point as a function of time, or the voltage profile along the cable at any given time. The results obtained have not been verified by actual field measurements but are in agreement with the results presented by previous authors. The computer simulation was used to study the effectiveness of different arrester placement schemes for branchless and single-branch systems. It was shown that, with prematurely aged cables whose BIL (basic impulse insulation level) has been considerably reduced, it is necessary to place arresters not only at the riser-pole, but also at all open points. This practice reduces the maximum voltage produced at any point along the cable and can therefore also be used with new cables to retard their aging process caused by exposure to repeated voltage surges