Quick Small Signal Stability Assessment of Power System byUsing Polynomial Approximation of Dynamic State EquationsEigenvalues

In power system dynamic analysis, computation of eigenvalues of state equations for various values of activedispatched powers is important. This concept provides a better understanding of the system dynamic behavior. In thispaper, an approximate equation extraction technique is proposed for fast computation of real-part of the most criticaleigenvalue of New England ۳۹-bus power system. Simulation by using MATLAB PSAT toolbox is carried out as a sourceof the initial data for finding a proper approximate function by using multivariable regression techniques. As anapplication example, the obtained polynomial approximate function has been applied to small signal stability constrainedoptimal power flow by using GAMS optimization package. The obtained polynomial function can be used with variousoptimization criteria in the valid interval of the approximation. Also this polynomial function can be re-used whengeneration cost functions are changed, without need for a new dynamic analysis. All of the dynamic analyses by PSATtoolbox are performed by using automatic intermediate codes cooperating with functions and variables of the PSATtoolbox and handy registration of numbers is avoided.

کلیدواژه ها:

Synchronous generator ، Small signal stability ، Optimal power flow ، Eigenvalue