Selection of Feedback Signal for Power System Damping Controller Based on Wide Area Measurements

A new approach is proposed to choose wide area feedback signals for wide area damping controller (WADC) in bulk power systems. Firstly, a novel signal selection benchmark is proposed, which is related to modulation amplitude of WADC and reflects the real control cost. According to this criterion, an index named dominant mode ratio (DMR) is proposed using linear system theory, and the algorithm based on time-domain curves and Prony analysis is also presented. Then, studies are carried out for the China Southern Power Grid (CSG) when using DMR to select an optimal wide area auxiliary input signal for the modulation control of Gui-Guang I HVDC-link to damp the inter-area oscillation between Yunnan and Guizhou. The effectiveness of DMR index is validated through time domain simulation and eigenvalue analysis.