PROBABILITY DISTRIBUTIONS OF SYSTEM AVERAGE INTERRUPTION FREQUENCY INDEX

System Average Interruption Frequency Index (SAIFI) is calculated as the average number of interruptions experienced by a customer per year. The SAIFI is one of several indices that measures the dependability of electrical grids. The frequency of electrical interruptions can be modeled using Poisson processes with various intensity functions depend on relative location and time. Calculating the distribution of the SAIFI assesses radial branching topology and can be beneficial in designing robust electrical networks. A probability generating function describing the complex networks was designed in Mathematica to find analytical probability distributions, expected values, and variance. Changing the rates of interruptions in the Poisson processes and varying the number of customers provides insight about consistency in complex radial systems. The model described in this study was created to be a useful tool for power companies to model network failure and improve reliability.