Transient stability of power systems using robust nonlinear second order sliding mode controller

The objective of this paper is to design a nonlinear second order sliding mode control for stabilizing the power angle of synchronous generator modeled by a standard third order model. The Standard Sliding Mode (SSM) controller produces oscillations (or “chattering”) in the closed-loop system. The new approach High Order Sliding Mode (HOSM) is proposed to reduce this phenomenon. The designed controller is smooth and robust with respect to different transient faults and enables to compensate the inherent nonlinearities of the generator. The responses of the system with the proposed controller are compared with those obtained with some other kinds of power stabilizers when the system is subjected to a variety of disturbances. Simulations on a single-machine in bus power system have demonstrated better performances compared with existing controllers. They show that the power system can keep transiently stable and achieve voltage regulation indirectly.