STUDY OF BIFURCATION ANALYSIS FOR DYNAMIC VOLTAGE STABILITY IN POWER SYSTEM

  N . Amjady1, * , M . R . Ansari Shahreza2     1 . Professor , Electrical & Computer Engineering Faculty , Semnan University , Semnan, Iran   2 . M . Sc. Student , Electrical & Computer Engineering Faculty, Semnan University, Semnan, Iran   * Corresponding Author: namjadi@semnan.ac.ir     Abstract   Voltage collapse is an inherently nonlinear phenomenon and it is suitable to use nonlinear analysis techniques such as bifurcation theory to study voltage collapse and to devise ways of avoiding it. For a power system, there are three different kinds of bifurcation points: the singularity induced bifurcation, saddle-node and hopf bifurcation.These three bifurcation sets are the boundary of the feasible region of the power system stability. When one equilibrium point passes through the boundary, the system will lose its stability. This paper focuses on bifurcation analysis for dynamic voltage stability. It also studies the eigenvalues behavior of the power system close to bifurcation points. This paper considers both unreduced Jacobian matrix eigenvalues and reduced ones, and it compares their results, too. MATLAB software has been used in this paper.     Keywords: Voltage C ollapse, Voltage S tability, Bifurcation A nalysis, Unreduced Jacobian M atrix, Reduced Jacobian M atrix