Reliability Assessment and Study the Effect of Substation Feeder Length on Failure Rate and Reliability Indices

Today, utilities are trying to maximize system reliability, improve efficiency, and reduce costs by using protection system, distributed generation system, by reconfiguring the feeder, by connecting the end of feeder to other substation and so on. However, when it tries to use some techniques (reconfiguring the feeder, connecting the end of the feeder to another substation); the techniques have positive and negative impact on reliability improvement. The substation which is taken in this paper has the System Average Interruption Frequency Index (SAIFI) and System Average Interruption Duration Index (SAIDI) is 521.46 interruptions per customer per year and 446.82 hours per customer per year respectively. The historical outage interruption data of the years of 2016-2018 has been used as a base year. The study has evaluated the new substation to improve the system reliability. The simulation results have been done with the help of Electrical Transient Analysis Program (ETAP 12.6) software. In this paper includes improvement of the system reliability of the feeder is supplied from two substations or new substation should be connected at the end of the feeder. Due to the new substation, the length of the feeder will vary, and the variation of the feeder has significant effect on power reliability. The value of SAIFI and SAIDI after the new substation connected is 169 and 96 respectively. Since the new substation has negative impact, the value of indices is not reduced more.