AN IMPROVED BACKSTEPPING SLIDING MODE CONTROL FOR POWER SYSTEMS WITH SUPERCONDUCTING MAGNETIC ENERGY STORAGE SYSTEM

摘要

In this paper, an improved backstepping sliding mode controller is presented for stabilizing an electric power system including a superconducting magnetic energy storage (SMES) system. In the first two steps of the design procedure, a feedback stabilizing control law is designed through improved backstepping strategy while a sliding mode surface is included in the final step. The resulting control law is employed not only to enhance transient stability and voltage regulation of the system including SMES device, but also to ensure the overall closed-loop system stability. The developed control law is evaluated on a single-machine infinite bus (SMIB) power system with SMES. The simulation results are used to demonstrate the performance of the designed scheme compared with that of a conventional backstepping control and an immersion and invariance (I&I) control. From the simulation, the proposed method has dynamic performances almost equal to the I&I one. Further, it is capable of improving both transiently stability and the dynamic properties better than the conventional backstepping method in spite of the presence of a large disturbance or a small disturbance.