Mevludin Glavic - Faculty of Elec.and Mech.Eng. University of Tuzla Republic of Bosnia and Herzegovina
Amir Nuhanovic - Faculty of Elec.and Mech.Eng. University of Tuzla Republic of Bosnia and Herzegovina
Naser PrIjaca - Faculty of Elec.and Mech.Eng. University of Tuzla Republic of Bosnia and Herzegovina
Sejid Tesnjak - Faculty of Elec. Erg. and Comp. Zagreb Republic of Croatia

Voltage collapse is associated with a stress condition of power system. Theoretical investigations of this problem have been resulted in many different approaches for analysis and solving of this complex phenomenon. It has been confirmed that the voltage instability problems start locally at the weakest nodes in a reduced area of the network, and the problem spreads to neighboring nodes, resulting in a cascading phenomenon [1]. Identification of reduced areas in a power system, with coherent behaviour of node voltage, may reduce the computational burden for voltage collapse analysis. To reduce the computational burden associated with problem of analysis of voltage instabality in large power networks, a network clustering is proposed. This paper presents a step-algorithm for clustering of the power network. The algorithm is based on a method which was initially developed for coherency based system decomposition into study and external areas based on the linearised dynamic model of power system. The examples included in this paper are based on simulation using 3 0 Bus New England test system. The system has 10 generator buses and 20 load buses that are interconnected by 37 branches. Keywords: Voltage instability, voltage collapse, reduced area of power system, clustering, norm of matrix