A novel approach to static voltage stability analysis

Résumé

A novel index to assess voltage stability is presented in this thesis. The proposed index contains useful information for voltage stability analysis such as voltage stability margins as well as the voltage controllability statuses of every load buses. A perturbation and Observation (P&O) algorithm is utilized to track the maximum loadability margins of all load buses. The voltage controllability status of each bus is examined using the sensitivity of the voltage magnitude to the injection of reactive power to the same bus. The reactive powervoltage sensitivity can be extracted from the inverse of the Jacobian matrix used in solving power flow equations by Newton-Raphson method. The thesis first explains the basic concepts of voltage stability and maximum loadability along with definitions and classifications of voltage stability and the conditions which lead to voltage instability. A brief description of L-index which is one of the most widely used conventional approaches to voltage stability assessment is then presented along with simulation results of this technique. The relationship between maximum loadability and Thevenin impedance is discussed next. The steps to develop the proposed Voltage Stability and Loadability (VSL) index are then explained. This is followed by a discussion of the simulation results and comparison between the results obtained from the VSL index and those of obtained from the L-index approach. Since the test cases consist of large power systems, all the results have not been presented in the chapter on simulation results. The detailed results of two case studies are presented in the Appendices. The results show the accuracy and robustness of the VSL index over the L-index. The results also confirm that the VSL index provides a precise measure of proximity to voltage instability. The final chapter contains a conclusion of the study and recommendations for future works.

Date	27 mars 2015
langue originale	Anglais américain
Établissement diplômant	École de technologie supérieure
Superviseur	Pierre Jean Lagacé (Directeur(-trice)) & Maarouf Saad (Codirecteur(-trice))