An approach to the damping of local modes of oscillations resulting from large hydraulic transients

A new method of damping of local modes of oscillations under large disturbance is presented in this paper. The digital governor controller is used. The controller operates in real time to improve the generating unit transients through the guide vane position and the runner blade position. The developed digital governor controller, whose control signals are adjusted using the on-line measurements, offers better damping effects for the generator oscillations under large disturbances than the conventional controller. Digital simulations of a hydroelectric power plant equipped with a low-head Kaplan turbine are performed and the comparisons between the digital governor control and the conventional governor control are presented. Simulation results show that the new controller offers better performances, than the conventional controller, when the system is subjected to large disturbances