Voltage stability analysis using conventional methods

Power systems all over the world have to operate very close to their stability limits owing to the ever increasing power demands. Voltage collapses usually occur on power systems which are heavily loaded or faulted or have shortage of reactive power. This paper analyses the voltage stability of the power system under increasing load conditions. Modal analysis technique and Continuation Power flow methods have been used to identify the weakest buses prone to voltage collapse. Eigen values are used to determine the system voltage stability and participation factors are used to determine the weakest bus which has the maximum contribution to voltage collapse of the system. FACTS controllers (SVC and STATCOM) are then applied to the weakest buses for voltage improvement. Comparison is made between the performances of the power system with and without FACTS compensation. The tests have been carried out on IEEE 30 and 57 bus systems. Further, this analysis has been extended to the North-Eastern Grid of India. This paper aims to study the improvement of voltage profile of power systems using FACTS devices.