The study involves the following stages: First, coupled-inductor and integrated magnetic structure used in Cuk converter circuit topologies are analyzed and the necessary information about these elements in circuit design is gathered. Also, benefits of using these magnetic elements are presented. Secondly / steady-state model, dynamic model and transfer functions of coupled-inductor Cuk converter topology are obtained via state-space averaging method. Third stage deals with determining the design criteria to be fulfilled by the implemented circuit. The selection of the circuit components and the design of the coupled-inductor providing ripple-free input current waveform are performed at this stage. Fourth stage introduces the experimental results of the implemented circuit operating in open loop mode. Besides, the controller design is carried out and the closed loop performance of the implemented circuit is presented in this stage.

In this dissertation the ac-link universal power converters, which are a new class of power converters, are introduced and studied in detail. The inputs and outputs of these converters may be dc, ac, single phase, or multi-phase. Therefore, they can be used in a variety of applications, including photovoltaic power generation, wind power generation, and electric vehicles. In these converters the link current and voltage are both alternating and their frequency can be high, which leads to the elimination of the dc electrolytic capacitors and the bulky low-frequency transformers. Therefore, the ac-link universal power converters are expected to have higher reliability and smaller size. Moreover, these converters are soft switching, which results in negligible switching losses and minimized current and voltage stress over devices. In the first part of the dissertation, the parallel ac-link universal power converter is studied in detail. This converter is an extension of the buck-boost converter. The series ac-link universal power converter, which is dual of the parallel ac-link universal power converter, is proposed in the second part of this dissertation. This converter is an extension of the Cuk converter. A modified configuration with fewer switches, named sparse ac-link universal power converter is proposed in the third part of this dissertation. The sparse ac-link universal power converters can appear as parallel or series. The performance of all these configurations is evaluated through simulations and experiments.

This theses analyzes Cuk converter, that is one of the dc to dc switching converters. For continuous inductor current mode and discontinuous inductor current mode, stedy state operation is analysied. Characteristic parameters are determined. Through State Space Averge Models, Small Signal Models are obtained. Parasitic Resistance effects on steady state and small signal models are determined. Efficency of the switching converter is derived. Open loop transfer functions for continous and discontinuous inductor curret mode are obtained. Parmeters for small signal behaviour is determined and stability is analysied. Parasitic resistance effects on transfer functions is determined. Therotecial analysis are verified with a simulations of designed converter.

The master’s thesis is focused on the creation of models of DC/DC converters and control program for input parameters and their configuration. The first part is theoretical and she is dedicated to the description of the program Matlab. The second chapter is dedicated to DC/DC converters. Their function is described there and the necessary equations for the design are derived. All of this is complemented by the calculation of line losses in semiconductor elements and the design of voltage and current regulator. The last two parts deal with the description of the created models in Simulink and control program in a graphical environment. The created program is able to edit and recalculate parameters of the converters, calculate line losses on semiconductor components, perform a model simulation or open it.