JEE_V2_N1_RP4 S. Sivanagaraju G. Sreenivasan K. Nagaraju J. Viswanatha Rao Journal on Electrical Engineering 2230 – 7176 2 1 27 35 voltage stability index, fast voltage stability index, load modeling, load flow, radial distribution system This paper presents two voltage stability indices for the analysis of radial distribution systems, namely VSI (Voltage Stability Index) and FVSI (Fast Voltage Stability Index), which are more sensitive to voltage collapse. Analysis of these indices is carried out with respect to changes in the reactive power of the system. Five types of load modeling, namely Constant Power, Constant Current, Constant Impedance, Exponential and Composite load models are considered for the purpose of stability analysis and comparative analysis is presented. For analyzing the above, a load flow technique is proposed, which involves a simple algebraic equation for calculating the receiving end voltage. The effectiveness of the proposed technique is tested on 15 node and 69 node radial distribution systems. July - September 2008 Copyright © 2008 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=327