PSS modification to stabilize synchronous machines during events with high Rate of Change of Frequency

This paper focuses on the modification of the Power System Stabilizer (PSS) for synchronous machines like turbine generators in conventional power plants. Through the increasing number of renewables like wind farms the stress profile of generators in large power plants has changed. Due to the facts that more volatile feeder inject power to the grid, higher change of frequency are expected. The PSS can decrease the stability of generators during such events which may lead to disconnection of the generator from the grid. Therefore, in this paper different options to modify the PSS of power generators are evaluated to improve the behavior of generators during transients of the mains frequency with focus on the protection system.