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Optimization Control Of Autonomously Switched Linear Systems With Constraints And Its Applications

Posted on:2016-05-15Degree:DoctorType:Dissertation
Country:ChinaCandidate:X L SongFull Text:PDF
GTID:1108330464469541Subject:Control theory and control engineering
Abstract/Summary:PDF Full Text Request
In energy storage systems of distributed power networks, balanced powers of this network have the features of uncertainty and uncontrollability, which set a power balanced process of the energy storage system, consisting in battery and supercapacitor, to be a power charge-discharge process with autonomous switching. At the same time, there exist physical constraints on storage and instantaneous balanced power capacities in the balanced process. In general, the electric charge and the dynamics of the charge- discharge process are different between each storage unit. These characteristics put forword some new challenges to study the switching control theory of the storage energy power balanced process.As the background of switching control of the storage energy balanced process, the dissertation overviews the available achievements on switching control. Then the dissertation mainly investigates optimization control methods of autonomously switched linear systems with constraints and arbitrarily switching signals, as well as their applications to the storage energy power balanced process. The main work and achievements in the dissertation inludues:1. Study the stabilization and optimization control problem of autonomously switched linear constrained systems. By the concept of common control Lyapunov functions, a switching controller with some adjusted parameters was designed to stabilize the system. Moreover, the switching controller was redesigned in the fashion of receding optimization by taking into account the contraint and cost performances. In theoretical, the controller was shown to be uniformly asymptotically stable, inverse optimality and robust section region(0.5, ∞) with respect to the arbitrarily switching signal. The numerical simulation results are used to illustrate the effectivess of the obtained results.2. Study the robust optimization control problem of autonomously switched linear systems with constraints and uncertianties. By computation of common robust control Lyapunov functions, the method used to design robust switching controllers with some free parameters was proposed for the switched system. In theoretical, the controller was shown to be uniformly asymptotically stable, inverse optimality and robust section region(0.5, ∞) with respect to the arbitrarily switching signal and the uncertain disturbance that is bouned by the system state. The controller was redesigned in the fashion of receding optimization and then its robustness was established. The simulation results on switching control of DC-DC converters were used to illustrate the effectivess of the obtained results.3. Study the switching control problem of the power balanced process of a single engery storage unit and propose the method used to design autonomously switching controllers of the power balanced process. The state of charge of energy storage units was defined as the controlled variables of the power balancement process. By the principle of conservation of energy, a switching mathematical model was estabilished to describle the power balanced process of the single engery storage unit. Taken into account the model parameters perturbances resulted from self-discharge rate, charge rate and discharge rate of the unit, a switched model with uncertainties was estabilished for the power balanced process of the single engery storage unit. Applied the theoretical results established above, an autonomously switching controller and an autonomously switching robut controller were designed for the power balanced process of the single engery storage unit. The simulation experiments on balanced power switching control of ultracapacitors, which is typical unit of power storage devices, were used to demonstrate the control performances of the designed balanced power controllers.4. Study the switching control problem of the power balanced process of hybrid engery storage systems(HESS) and propose an autonomously switching receding optimization control method for the HESS. The continuous-time switched model of charge load, the constraint model and performance cost functions of power balancement were estabilished to describle charge/discharge process of HESS. Then a receding optimization control scheme was proposed to balance powers of HESS, which was used to reject the fluctuation of renewable energy power. Compared to the linear quadratic optimal control method, the autonomously switching receding optimization controller of power balancement obtained here was demonstrated to not only greatly reject the fluctuation of renewable energy power, but also satify the constraints of power balancement of HESS. The compared results also showed the control performances of the obtained balanced power controller.5. Finally, the dissertation gave conclusions and listed some promise topics to be pursued in the future work.
Keywords/Search Tags:switched systems, switching control, constrained optimization control, receding horizon control, storage energy power balanced control
PDF Full Text Request
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