To maintain a high degree of reliability, the impact of major disturbances, such as a large sudden fault, should be considered during power system stabilizer design. The problem of designing controllers to prevent an electric power system losing synchronism after a large sudden fault is of great importance in power system design. The conventional stabilizer designs based on approximate linearization models are not adequate for large disturbances. When a large fault occurs, the behavior of the system changes a lot, and in many cases a linear controller cannot maintain adequate stability. In this paper, by using the input-output feedback linearization technique and asymptotic output tracking theorem, a novel excitation control system is resented. Improvement of transient stability and voltage regulation of a single machine infinite bus power system in the presence of a symmetrical three phases short-circuit fault is considered as a test example. The simulation results show that the power system can keep transiently stable and achieve good post fault voltage regulation with the proposed nonlinear controller.
