Self-testing and self-tuning of power system stabilizers using Prony analysis

This paper presents a new method for self-testing and self-tuning of power system stabilizers (PSSs) using Prony analysis. Prony analysis detects oscillation frequency, damping, phase and amplitude in measured waveforms. By applying this technique to signals of generator speed, output power, and generator internal induced voltage, weak damping oscillations are detected and the PSS parameters can be modified to damp the oscillations. When a disturbance occurs and a weak damping is detected, effectiveness of the installed PSS is verified by checking the phase angle between generator speed and internal induced voltage. Based on the test results, self-tuning is performed by changing phase compensation and gain parameters considering the phase lag of the excitation system. Simulation results show that the proposed method is effective both in a one-machine system and in a multimachine system. The method is especially useful for detecting and damping wide-area, low-frequency oscillation modes.