Novel non-linear control of DFIG and UPFC for transient stability increment of power system

This paper offers novel non-linear control of a doubly fed induction generator (DFIG) and unified power flow controller (UPFC) for transient stability increment with transient energy function (TEF) and sliding mode observer in a power system. First, the TEF technique is considered for the damping control in a power system with a synchronous generator (SG), DFIG, and UPFC, and then the controller time-derivative signals are estimated by a second-order sliding mode observer. The importance of the issue is in the employ of a complete UPFC model. Also, a one-axis model is used for DFIG that is similar to the SG model. Another characteristic of the novel non-linear technique is robust versus system topology changes and variable time delay of the control signals. To evaluate the performance of the novel non-linear control method for increment transient stability, simulation studies are performed on a two-machine connected to an infinite bus (TMIB), the IEEE 9-bus, and the New England Standard 39-bus power system. The results determine that the novel non-linear control method decreases the first swing of fluctuations admissibly and enhancement stability margins considerably.