Optimal Placement of Unified Power Flow Controllers (UPFC) for Losses Reduction and Improve Voltage Stability Based on Sensitivity Analysis in 500 kV Java-Bali Electrical Power System

Demand for electricity is increasing rapidly, the consequence of this is a threat to the stability of the electrical system, one of which is the voltage stability. Flexible alternating current transmission system (FACTS) is a solid state electronic device is capable to regulate the transmission of electrical power be flexibly used to overcome these problems. This research will analyse the influence of unified power flow controller (UPFC) placement, as one of the types of FACTS on the buses or line of the most critical voltage stability of the power system by using case Java-Bali 500 kV by means of simulation using PSAT software. Voltage stability observed with the help of the PV curve can indicate the value of each voltage at any operating conditions. Voltage value in which the system reaches the maximum loading parameter (MLP) is used to select the most critical bus or line as the location of UPFC placement. Installation of UPFC in case of Java-Bali 500 kV can reduce active power losses by 0,0166 p.u. (19,17%) and reactive power losses by 0,0076 p.u. (1,21 %) and λ by 0,761 p.u. (19,78 %).