Amélioration de la stabilité de réseau électrique par les systèmes FACTS

Abstract

Despite the rapid evolution of protective devices and control, the electro-energetic systems are often subject to disturbance of various sources able to involve inopportune releases of its components. These disturbances affect the loss of the system stability and cause an important imbalance between the production and the consumption of the electric power. This state often involves a collapse of the entire network. The correct operation of a network is based on its control parameters (voltage, frequency, impedance and stability). The parameter "voltage" must be controlled, if not, the voltage drops or over voltage cause breakdowns and cuts in the energy system. The evolution of power electronics offered great opportunities to relieve transmission lines in terms of voltage, angle of transmission and power flow. Hence a new approach was born "FACTS: flexible alternating current transmission system. FACTS can be placed in series, parallel or series-parallel. In this thesis, we present the transient stability state evaluation and the determination of the stability limits in an electrical energy system transport by the FACTS devices (SVC,TCSC and UPFC) for the case of defect: phase short circuit. The numerical simulations, the calculations and graphical representations results are obtained by using the MATLAB toolbox PSAT (Power System Analysis Toolbox).