Transient stability enhancement and voltage regulation of power systems

Major objectives in power system control design are to prevent an electric power system losing synchronism after a large sudden fault and to achieve good postfault regulation of the generator terminal voltage. Important control ideas used to improve the transient stability of the power system are to rapidly increase excitation and to decrease the mechanical input power at the same time as a fault occurs. In this paper, we concentrate our attention on power systems after a symmetrical 3-phase short circuit fault. By using the direct feedback linearization (DFL) technique, a novel excitation controller and coordinated controller (excitation and fast valving controller) are given. The simulation results show that the power system can keep transiently stable and achieve good postfault voltage regulation with the nonlinear controllers. Thus they have prospects for an industrial application.