The Influence of Rotor Damping System of Turbine Generator on Small Disturbance Characteristic

In this paper, we study the influence of rotor damping system on small disturbance characteristic of turbine generator connected to power system. Considering the complex rotor damping structure of turbine generator, we establish Field-circuit Coupled Time-Step Finite Element Model and test this model by the experiment of 7.5 kW model machine. Based on this model, we take a 300 MW turbine generator as an example to study the influence of damping bar, rotor iron core and conductive slot wedge on small disturbance characteristic. We investigate the importance of the rotor damping system to small disturbance characteristic and find its impact is not negligible. By comparing the small disturbance characteristic indexes affected by three components of rotor damping system respectively, we conclude that the rotor slot wedge plays a leading role in small disturbance characteristic..