Frequency spectrum-based optimal design of power system stabilizer for primary frequency control

Power system is a highly non-linear system. The nonlinearity of the system causes different output patterns around the different equilibrium point. Therefore for every transition from one equilibrium point to another equilibrium point, the behavior of system changes. The frequency, being the most critical parameter of the system, the drift from its equilibrium point due to various reasons like small and large disturbances, should be strictly damped out. The power system stabilizer (PSS), not only used for damping the angular velocity drift of the machine but also for frequency control. The feedback signal provided by PSS to the system is commonly the magnitude of drift of angular velocity of machine or drift of load angle. This paper presents a frequency spectrum (FS) based approach for PSS design. The methodology is supported by appropriate theoretical and simulation evidence. The theoretical aspect represents state space design of system and simulation is done for a single machine infinite bus system (SMIB) and well known IEEE New England 10 machine 39 bus system (NE 39 test system).