Pichai Aree

pp. 827 - 838

Abstract

The transfer-function block-diagram model of single-machine infinite-bus power system has been a
popular analytical tool amongst power engineers for explaining and assessing synchronous generator dynamic
behaviors. In previous studies, the effects of local load together with damper circuit on generator damping
have not yet been addressed because neither of them was integrated into this model. Since the model only
accounts for the generator main field circuit, it may not always yield a realistic damping assessment due to
lack of damper circuit representation. This paper presents an extended transfer-function block-diagram
model, which includes one of the q-axis damper circuits as well as local load. This allows a more realistic
investigation of the local load effect on the generator damping. The extended model is applied to assess the
generator dynamic performance. The results show that the damping power components mostly derived from
the q-axis damper and the field circuits can be improved according to the local load. The frequency response
method is employed to carry out the fundamental analysis.

Keywords

• power system stability
• damping
• local load