Application of dual-input PSS to 343 MVA pumped storage unit and its validation

This work describes practical tuning methods and testing of a dual-input prototype PSS, which uses both frequency and power, with the 343 MVA Muju P/P #2 in the KEPCO system to enhance the damping of both local and inter-area modes. A Bode plot was drawn to tune the PSS's time constants to compensate for phase lag. In addition, eigenvalue analysis was used to determine a reliable PSS gain, Ks, and a time-domain transient program was used to verify safe operation of the PSS in the presence of predictable disturbances, such as the AVR step test and generator unloading. In the on-site test, the AVR step tests at 300 MW loading at Muju P/P #2 were implemented with a dual-input prototype PSS to check to what extent the PSS damped the power oscillation of the disturbances. The recorded data showed that power oscillations were reduced considerably as the PSS gain was increased.