Application of FACTS technology for power system control

This paper describes the impact of the FACTS application on the power network using EMTDC simulation package. KEPCO (Korea Electric Power Corporation) has begun the operation of the plusmn80 MVA UPFC (unified power flow controller) from the year 2003 on the 154 kV transmission system. The UPFC consists of two voltage source inverters (VSI), STATCOM and SSSC, which are connected through a common DC link capacitor. Through a combination of both VSIs, the UPFC can control bus voltage, real and reactive power flow. But, in some cases, each VSI can be operated independently according to operation modes. After all, The UPFC can be operated 3 operation mode; SSSC, STATCOM and UPFC mode. The paper describes the fundamental operating effects and basic control approach of a SSSC mode operation of KEPCO UPFC to the power system