Study of Characteristics of Fault in Overhead and Underground Cable Distribution System Using Experimental Test Bench

Abstract

This paper is focused on the behavior of current waveform when the single line to ground fault occurs on the pi-lumped equivalent circuit experimental test bench of distribution system. The experimental test bench can be divided into the distribution system either overhead line or underground cable. The parameter of experimental test bench is calculated based on per-unit method by using the data from the 115 kV distribution system in Thailand. The various case studies are performed by changing the type of distribution system, the location of fault, the inception angle of fault including varying the load. The obtained results show that, during the fault occurrence, the current waveform has a sudden change and increases more than 10 times in comparison with normal condition. Finally, the results from the experimental test bench will be beneficial in the behavioral study of the fault current in case of both overhead line and underground cable and will be development of the short-circuit protection system in the distribution system.