Sliding Mode Control of Energy Storage Systems for Reshaping the Accelerating Power of Synchronous Generators

The rotor angle stability has been a key concern in the stable operation of power systems, especially in the renewable energy age. However, to improve the power system rotor angle stability, none of the existing methods considered achieving it through reshaping the accelerating power of synchronous generators (SGs) and decoupling them after grid disturbances. In this paper, the sliding mode control (SMC) theory is utilized to tackle the coupling among SGs. After careful modeling and controller design, a SMC-based energy storage system (ESS) controller is proposed to temporarily decouple the interacted SGs through reshaping the accelerating power of SGs to the desired value. The proposed controller can: 1) drive the SG’s accelerating power to follow the reference in infinite time; 2) decouple the interacted SG dynamics and stabilize the disturbed SG exponentially. The proposed controller achieves the above two goals without using the communication and hard-to-estimate SG rotor angles. Case studies are carried out on the 2-Area 4-Generator System and the Australian 14-Generator Equivalent System to demonstrate the effectiveness of the proposed controller. The results also show that the proposed controller stabilizes the disturbed power systems with better performance over existing controllers.