Damping Improvement of Multi Machine Power System Oscillations by using UPFC Controller based Multi-input Nonlinear Backstepping Controller

Stability and damping oscillations during fault occurrence are two important challenges which have attracted the attention of the power systems designers. In this paper Improvement of the Damping of Multi Machine Power System Oscillations is considered by using UPFC. The applied control algorithm for the damping oscillations is the Multi-input Nonlinear Back-stepping Controller. The injection model of UPFC is used for modeling of UPFC, Using of this model decreases 4 input control of UPFC  to two inputs and the performance of power system is improved by this control method. Performance of this control algorithm in comparison with classical method is shown, more robustness, more independent to the work point and using of whole control variables of UPFC. The proposed control method, is simulated for a single machine connected to infinite bus and a multi-machine(9 bus IEEE) power system. The results of simulation, is illustrated that the performance of designed multi-input Back-stepping controller rather is better than conventional controller.