English abstract
Voltage stability is an important factor, which needs to be taken into consideration during the planning and operation of electrical power systems in order to avoid voltage collapse and subsequently partial or full system blackout. From the voltage stability analysis point of view, system operators need to know not only the severity of their system, but also the mechanisms that cause voltage instability. This project presents several published methods and techniques used to determine voltage stability in electrical power systems, which are the Q-V and P-V curves; singular value decomposition; modal analysis; V-Q sensitivity, and the reduced determinant. The modal analysis and the singular value decomposition are applied to both typical 11 bus power system and the Ministry of Housing, Electricity, and Water (MHEW) 46 bus interconnected power system of year 2001 in order to determine the weakest load areas, which could lead the system to voltage instability. The results presented in this work are obtained using a computer program developed in MATLAB. The results obtained using the MATLAB program for the modal analysis and V-Q sensitivity were also verified using the NEPLAN power system analysis software. The MW and MVAR security margins of the weakest load area in the MHEW power system have been determined. Remedial actions such as installing shunt var compensation (SVC) have been proposed to improve the voltage stability of the MHEW power system
