Extended Backstepping Method for Single-Machine Infinite-Bus Power Systems With SMES

This brief studies the stability of single-machine infinite-bus power systems with superconducting magnetic energy storage (SMES) via simultaneous design of generator excitation control and SMES control. Since the object model is of non-strict-feedback form and thus the traditional backstepping method is not applicable, we propose an extended backstepping method for a class of general nonlinear systems. Then, we apply the proposed method to the object model and design the generator excitation controller and SMES controller simultaneously, which stabilize the power angle, the generator terminal voltage, and the power oscillation. In addition, we improve the transient and steady-state performances of power systems by introducing class K functions in the design process. Simulation results also show the effectiveness and advantage of the proposed controller.