Voltage sag assessment and Area of vulnerability due to balanced fault for 11 bus system

ABSTRACT: The voltage sag is very common issue of power quality. In order to assess voltage sag stochastic method is used. This paper presents an analytical method to assess voltage sag frequency and area of vulnerability for buses given in the system. The area of vulnerability (AOV) graphically represents fault zones which lead to voltage sag of desired magnitude on observation bus. The results are presented for 11 bus test system. As voltage sag occurs due to short circuit faults i.e balanced and unbalanced fault. This study is done for balanced faults occurring in the system