This paper describes practical tuning methods and testing of a digital PSS, which uses both frequency and power, with the 220MVA Chungpyung P/P # 1 in the KEPCO system to enchance the damping of local modes. In the first step, the objective phase of PSS is computed through a phase leading function to provide compensation between the exciter reference point and the generator air-gap torque before tuning the PSS’s time consatns. In a addition, eigenvalue analysis was used to determine a range of PSS’s gain, which is the more useful for field testing rather than a single gain value. The Real-Time Digital Simulator was used to verify safe operations of the PSS in the presence of disturbances, such as AVR step and three phase fault.
