In heavily loaded systems, voltage stability limit is usually dominant and voltage instability is usually observed following large disturbance. This is typically the case in the deregulated environment as the transmission systems are operating under more stressed condition due to increased transaction level associated with open access. In this paper simple voltage stability analysis is carried out for a multibus power system (26 bus system) using V-Q sensitivity analysis and modal analysis. The bus participation, line participation and generator participation in critical mode of voltage stability is determined. This is useful for implementation of contingencies in power system for further study of voltage stability. A novel idea of small increment in reactive power and distributing the same in proportional to bus participation factor for calculation of generator and line participation is presented. Also the correlation between the voltage sensitivity factor and bus participation factor is established for identification of weak buses.
Keywords: voltage stability, shunt compensation, voltage sensitivity factor, VSF, reactive power, voltage instability, weak elements, modal analysis, sensitivity analysis, elements participation factor