Navid Ghaffarzadeh - Assistant Professor, Technical and Engineering Faculty, Imam Khomeini International University, Qazvin, Iran,
Haniyeh Marefatjou - MSc.students Of Imam Khomeini International University Qazvin,Iran,
Hossein Najafkhani

In this paper steady-state modeling of Static VAR Compensator (SVC) and Unified Power Flow Controller (UPFC) for power flow studies has been represented and discussed in details. Also Comparisonbetween performance of UPFC and SVC for damping power system oscillations has been done. Case studies are carried on 11 busnetwork in two areas. Simulation is done with PSAT in MATLAB. Load flow was implemented by using Newton Raphson method.Simulation results show the proper performance of UPFC and SVC to improve voltage control and power flows on the lines, and properperformance of UPFC for damping power system oscillations. In Fact in this paper we have desired the effect of SVC and UPFC in load flowstudies(active and reactive power flows in the line and active and reactive power flows at the bus and voltage/angle),also to effect OfUPFC for damping system oscillations. The UPFC has a PowerOscillations Damping (POD) unit. The POD controller consists of an active power measurement system, a general gain, a low-pass filter, a washout high-pass filter, a lead compensator, and an output limiter. The inputs to the POD controller for UPFC are the current flowing in L5.

SVC, UPFC, Power Flow, Newton-Raphson Method,Damping Oscillation, POD