FACTS is a flexible alternating current transmission system which is used to transfer AC power. FACTS technology is a way of improving power system controllability's and power transfer. There are various FACTS devices used for various purpose. In this paper, we are using UPFC. UPFC is a combination of STATCOM and SSSC. UPFC controls the power flow and regulate the voltage. This paper represents the various modes of operation using series and shunt converters. Unified Power Flow Controller (UPFC) is IGBT based voltage source converter which shows the step change. © 2019 IEEE.