Oscillation Damping in Momentarily Loss of Excitation Generators Based on Power System Stabilizers

There are many causes that lead the generator to Loss of Excitation (LOE) such as, a shortcircuit in the field winding, unexpectedly open field breaker or a failure in the excitation system.LOE protection schemes are widely used to detect these faults quickly, but they remaininsensitive to the external faults and for other disturbances in the power system. Power SystemStabilizer (PSS) is used to measure and damp the power oscillations, which occur by cause ofexternal faults, through the set point of the voltage regulator.In this paper, the Multi-Band and Generic Power System Stabilizers (MB-PSS and GPSS) arebeen reviewed and examined in case of the generator momentarily loss its excitation, the powersystem must remain stable via the proposed stabilizer. The case study is based on radial powersystem are including: a main power station is connected with a substation across the transmissionlines and a step-up transformer. The salient-pole synchronous generator is rotated by theHydraulic Turbine and Governor (HTG) which have auto control when disturbance occurs in thepower system. The performance of the power system is demonstrated by using the simulation.