Reducing the effect of vortex rope oscillation on hydro units by power system stabilizer designed using Genetic Algorithm

The operation under part load condition is one of the major difficulties in hydro units. Especially severe pressure oscillations can occur for Francis turbine units in part load condition. They are generated by an unsteady vortex behaviour in the draft tube, so-called vortex rope. This paper presents PSS (Power system stabilizer) design for Vortex Rope Oscillation (VRO) in single machine infinite bus system. The main motivation for this design is to stabilize or to control low-frequency oscillation on power systems caused by VRO. The optimal parameters of the PSS are obtained employing Genetic Algorithm (GA) using Integral of Time Multiplied Absolute Value of the Error (ITAE) criteria. Finally, the simulation results of PSS behaviour for Vortex Rope Oscillation are discussed.