Boundary layer sliding mode control for multimachine power systems improved by antiwindup integral action

A new sliding mode based, excitation control is proposed for multimachine power systems that improves the transient stability. The design is developed on an equivalent model of the system obtained by using the backstepping technique. In order to avoid chattering and to achieve zero steady-state error in the presence of disturbances, the conventional signum function method is replaced by the boundary layer sliding mode technique which is suitably modified by including antiwindup integral action. As shown in the paper by an extensive stability analysis and simulation results on a three-machine power system, the proposed control scheme ensures asymptotic stability of all the system variables, reduction of chattering and fast response.