Sliding mode control with mismatched disturbance observer for chaotic oscillation in a seven-dimensional power system model

In this article, a sliding mode control scheme with mismatched disturbance observer to achieve chaos control in power system is presented. A novel design method of mismatched disturbance observer is proposed for a second-order system with mismatched disturbance, it is proved that the designed observer can theoretically observe disturbances with arbitrary accuracy by adjusting the parameters of disturbance observer artificially, and the designed controller realizes uniformly ultimately bounded asymptotic system stability. The designed disturbance observer and controller exhibit two main features. The first is the form of the observer is simpler than the existing observer. The other is the designed observer and controller do not contain system functions, which makes them can be applied to the control of complex systems. Furthermore, the proposed control scheme is adopted to design mismatched disturbance observers and controllers for suppressing chaotic oscillation in a seven-dimensional power system model and simulation results are presented to demonstrate its validity.