Frequency dependant estimation of damping and synchronizing torque coefficients in power systems

One of the challenging problems in large interconnected networks is finding oscillation frequency and damping factors of the system electro-mechanical oscillations, which is usually done by eigenanalysis techniques. In this paper a novel and simple method is proposed to find the synchronizing and damping torque coefficients to estimate the oscillation frequency and associated dampings analytically. This is achieved by combining the generator (including excitation and power system stabilizers) and network circuit equations and then applying small signal stability analysis. In addition to simplicity and being less time-consuming, the ability to find the damping coefficients separately for any desired frequency makes this method a reliable technique. The numerical results on small sample power systems illustrate the feasibility of the proposed method and sample performance characteristics.