خلیل گرگانی فیروزجاه

Expansion of the distribution network and close distance of distribution transformers lead to allocation of excessive surge arresters, while the number of arresters failures in the traditional routine may cause unwanted power outages. Therefore, this paper aims to propose a method to decrease the number of surge arresters as well as keep overvoltage protection of the network in the event of direct lightning strokes. According to different bus structures of the distribution network, elimination of allocated arresters is carried out by investigation of their protective distances at different stroke conditions. A guideline is presented for the IEEE 34-bus distribution system and the outcome is compared with the standard. The analysis is also carried out for a practical distribution network at West Mazandaran Power Distribution Company, Mazandaran, Iran. Possibilities for the elimination of surge arresters at the transformer station and installation of new transformers without allocation of new arresters are investigated in the analysis. Simulations are carried out based on the standard 8/20 lightning current wave at a transient analysis of DIgSILENT.