Dc - Dc Hybrid System Modeling And Control Of The Converter

DC-DC converters are time-variable nonlinear systems and the classical theory is not suitable to analyze and control these systems, the complexity of modeling and control for them affects the deep research and application of them. Therefore, simplifying the modeling process and control of DC-DC converters has important theoretical and engineering value in their analysis, design and application. In this paper, DC-DC converters are considered as a kind hybrid dynamic system combined continuous state variable with discrete switched variable together, which is called switched linear system. Therefore, the problem of hybrid modeling and control design for DC-DC converter which is based on hybrid system theory and linear matrix inequalities (LMIs) method is investigated in the dissertation. The main contributions are as follows:Firstly, according to topologies and operation principle of DC-DC converters, the ideal state DC-DC converter switched linear system model are built with four basic DC-DC converter as example, and the switched linear system model transform into error tracking system model. So the problem become finding a switching rule which can make the state of the system is finally converges to a desired "switched equilibrium". Then, based on the error tracking system model and using the Lyapunov stability theory directly, the control strategy for the converter system is given. Finally, the result proved the final error tracking system is stabilizable and the system has good output regulation performance.Secondly, the DC-DC converter switching linear system model with parasitic parameters and uncertain parameters are built, and then the switching system model transform into error tracking system model with uncertainties. Using switching linear system theory on this basis, the robust control design for the error tracking system model with uncertainties is discussed, and the design can make sure the system has good dynamic performance.In the ending, DC-DC converter with uncertain parameters and disturbance modeled as switched affine linear system is mainly discussed. Then the switching system model transform into error tracking system model with uncertain parameters and disturbance. On this basis, consider H∞model performance analysis, a method for designing a switching rule such that the system is asymptotically stabilizable with H∞disturbance attenuation leve γ is presented.