In this modern era it can not be denied that all human beings have enormous dependence with electrical energy. In the distribution of electrical energy, the performance of the distribution network must be properly justified, because in the distribution network is very likely the occurrence of interference in the distribution network resulting in power outages. This final project is designed to analyze the performance of medium-voltage distribution network of 20 kV Wirobrajan area, and the performance of protection system when there is disturbance on each repeater of distribution network for one year in the year 2017. This is done because of frequent blackout in wirobrajan kususnya area 2017. Based on the analysis, the comparison of SAIFI, SAIDI, and CAIDI values computed with SPLN Standard 68-2 1986 and IEEE Std 1366-2003 there are some repeats whose default values exceed the maximum limit. Performance protection systems on the distribution network of each repeater always work well, any protection disturbance always detects the interference properly and direct protection works. From the data that has been analyzed, the biggest disruption lies in WBN01 repeater this is because the location of WBN01 repeater is on Jl. Hos Cokroaminoto with the most disturbance in its direct review, the distribution network is too closely related to buildings such as buildings, billboards/billboards and the number of networks adjacent to trees and in case of disturbance over the last one in WBN01 due to the large number of trees attached to network resulting in a short circuit, and the number of billboard billboard that collapsed about the distribution network resulting in a short circuit.