Quick Small Signal Stability Assessment of Power System by Using Polynomial Approximation of Dynamic State Equations Eigenvalues

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

کلیدواژه ها:

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