Model based and model free control of higher order DC DC converters

Abstract

This dissertation is a set of papers published in high impact journals such as IEEE Transactions on Industrial Electronics and MDPI-Power Electronics. The unifying component of all these works is based on data-driven control approaches for voltage bus stabilization of higher order power converters in stand alone operation, as well as for DC power converters interacting within a DC network or interacting with constant power loads. With the aim of developing the different control approaches for such converter structures, we consider the concepts from Behavioral systems theory such as higher-order differential equations, and the image representation of a system to develop a model based approach employing the pole placement technique. In contrast, for a model-free approach we consider the linear difference systems and the Quadratic difference forms which are functionals to study the stability of discrete time systems taking into account either pole placement technique or Lyapunov and passivity theory. External variables from Behavioral systems theory are also introduced in order to achieve system identification by means of measured data such as input current, output voltage and duty cycle. The system identification process is achieved by the so called persistency of excitation condition, which permits to find an annihilator from a singular value decomposition factorization of a Hankel matrix which is constructed from the measured data. This annihilator represents the left kernel of the system, in other words, it represents the laws of the system. Experimental and simulation results were carried out in the Power Electronics Research Lab - PELS Monterrey Chapter, in order to validate our proposed approaches. Analysis, design and PCB layout were carried out also. Uncertainties such as input voltage and load changes were applied to the converters to corroborate the robustness of the proposed approaches.