Application of damping torque analysis index for coordinated tuning of stabilizers in the large power grid

Cai H^* and Littler T

¹School of Electronics, Electrical Engineering and Computer Science, Queen’s University Belfast, Northern Ireland, UK

*Corresponding Author’s Email: caihui300@hotmail.com

Accepted 24 March 2013

Abstract

This paper considers the coordinated tuning of stabilizers attached to the primary control loops of a Synchronous Generator (SG), Doubly Fed Induction Generator (DFIG) and Energy Storage System (ESS) in a large power grid. The indices obtained from a Damping Torque Analysis (DTA) method are used to evaluate the impact of different stabilizers subject to a range of low-frequency oscillations. According to the DTA Indices, a coordinated stabilizer-tuning strategy is proposed. Selected stabilizers are tuned effectively to dampen target oscillations without causing ‘eigenvalue drift’. The damping ratios of the interarea oscillation modes and local modes in large power grids can be increased beyond satisfied values, without time-intensive and redundant-stabilizer adjustment.

Keywords: stabilizer, coordinated tuning, DTA Index, low-frequency oscillation, damping ratio