Bifurcstion Theory Applied To Analyse Stability In Power System Including FACTS Equipments

Improving voltage stability and protecting the system from voltage collapse are important for power system security. As an advanced and modern technology, FACTS is able to control system parameters flexibly and quickly so that more and more attention have been pay to it as it is an important way to protect power system from voltage instability. This thesis focuses on the effect of FACTS devices in the power of transfer capability and voltage stability of power system using analytical method of bifurcation in the nonlinear system theory and the software of bifurcation analysis.The theory of power system voltage stability, the analytical method of voltage stability in power system, analyzing voltage stability in power system based on the theory of bifurcation and the software AUTO97, which is a general continuation and bifurcation software have been discussed.Based on the analyze of the models of Static Var Compensator (SVC) and Thyristor-Controlled Series Compensator (TCSC), which are connected to a specific power system, including the basic character of theirs circuits, to select the optimal location of SVC and TCSC and compare their effect to the power line, using AUTO97 as the analytical tool.With the theory of bifurcation and numerical simulation, it further analyzed the relation between output power and out voltage under the compensation of SVC and TCSC, and the mechanism of voltage oscillation and voltage collapse.The analytical result using the theory of bifurcation and the tool of AUTO97 states Thyristor-Controlled Series Compensator (TCSC) and Static Var Compensator (SVC) most popular installed in the power system are typically series compensation and shunt compensation devices in the Flexible AC Transmission System (FACTS) can improveline transmission ability and system stability. Comparatively speaking,SVC can improve line transmission ability better than TCSC, while TCSC can effect the point voltage better than SVC.By the analysis of a power system embodies the devices of the Flexible AC Transmission System (FACTS) used to improve the line transmission ability and system stability to avoid voltage oscillation and voltage collapse, this thesis has done good work.