Mechanism of Active-Power-PSS Low-frequency Oscillation Suppression and Characteristic of Anti-regulation

For the purpose of oscillation suppression, PSS will show measurable oscillation of the power system and transform it appropriately, then feedback to excitation regulator to produce additional damping torque. PSS commonly used active power as a signal generator, compared with the speed-PSS, the active-power-PSS has some characteristics including strong signal, no introduction of interference and do not inspire tensional oscillation of shaft train. However, at the changes of prime mover, Active-power-PSS may cause anti-regulation of excitation voltage and reactive power substantially changes.