Enhancing the Voltage Stability of the Nigerian 330KV 48-Bus Power System Network Using Modal/Eigenvalue Analysis

This study is based on the application of modal analysis on the 48 bus 330KV Nigerian Network using PSAT MATLAB Toolbox. The Modal/Eigenvalue analysis technique was used to investigate the stability of the 48-bus Nigerian power network system. The modal method calculates the smallest eigenvalue and all the associated eigenvectors of the Jacobian matrix using the steady state mode. The magnitude of the smallest eigenvalue estimates the proximity of the system to the voltage instability. The participation factor can be employed to identify the bus that provides the highest contribution to the instability of the system. The 48-bus Nigerian network was simulated under static loads and changing loads and Modal/Eigenvalue analysis was performed on the system under each of these conditions. It was found that increase in loads at the three selected weakest buses reduced the stability of the system. Results obtained in this study proved that reactive power compensators were able to drastically improve the stability profile of the 48 bus Nigerian network and even rescue the system at the event of voltage instability especially the ones caused by change in loads. Keywords: Modal, voltage stability, eigenvalue, participation factors. MATLAB Toolbox, PSAT DOI : 10.7176/JIEA/9-7-04 Publication date: December 31 st 2019