Power System Stabilizer Tuning & Testing – EUMAC professionals have been actively involved with power system stabilizer (PSS) testing and tuning since their introduction in the late 1960’s. The PSS is, in essence, a “cruise control” on turbine generator speed.  Most power system stabilizers sense turbine generator speed deviations from the power system synchronous frequency.  Others operate upon rate of change of generator power output.  With either input type, the PSS develops a supplementary input signal to the generator’s automatic voltage regulator’s (AVR) summing junction.  This supplementary input slightly modulates the generator field current.  The modulation creates a damping torque on the turbine generator rotor that completely cancels speed deviations (and the power system remains stable).  EUMAC can provide the necessary test instrumentation and perform the field testing required to set your PSS for optimal damping of inter-area and local mode oscillations.