Stability Research Of Switched Two-machine Power Systems

Power systems are multidimensional, strong non-linear dynamic and large-scale systems, which are combined with new research results. The fundamental aim is to enhance the dynamic performance of complex power system as well as the stability of the system, so as to improve the performance and safety of electricity supply services.Power systems are kind of hybrid systems which contain both continuous dynamics and discrete dynamics. As hybrid systems, because of the power systems'complexity, how to combine the switched system theory with the power systems is a very difficult and practical problem.In this paper, switched system theory and power systems are combined and power systems switched control problem is investigated, based on switched system theory.The main works are as follows:Firstly, on the basis of the power systems models and the literatures, the switched model of power systems has been established (switched two-machine power systems). At the same time the switched model of the power systems with uncertain parameters has also been established.Secondly, on the basis of the switched models of two-machine power system, asymptotical stability under arbitrary switched has been studied with the common Lyapunov function method. Compared with the analysis of the literatures, the theory of switched system is much more simple and easier in the process of the simplifying problem, proof, and designing controller. The simulation results are given to illustrate the effect of the results.Thirdly, the robust control problem of the switched two-machine power systems with uncertain parameters has been studied. On the basis of the switched model of two-machine power systems with uncertain parameters, the controller and adaptive law is been designed. Asymptotical stability under arbitrary switching is been studied. Meanwhile, simulation results are given.Finally, concluding remarks are presented at the end of this dissertation. And next work is pointed out.