The purpose of this thesis is to take the first steps in the development of a single-phase grid-connected photovoltaic system realizable by the AMER platform of the Department of Automation and Applied Informatics for educational purposes. The task is approached with the model-based design methodology in MATLAB Simulink environment. The proposed system includes the complete plant model of a double-stage PV system with MPPT algorithm, grid synchronization based on PLL design and PR control for the full bridge inverter. Reactive power (VAR) control is also supported.
Chapter 1 includes a brief introduction to the actual trends of the renewable energy sector and sets the general requirements for modern distributed photovoltaic systems. Then, the AMER platform is thoroughly described and hardware requirements are derived based on its configuration.
The goal of Chapter 2 is to sketch the theoretical background of the thesis. Following a general description of grid-connected PV systems, the typical topology and features of a double-stage PV inverter are investigated. The main part of this chapter is the detailed discussion of the components of such systems, including the derivation of the so-called one-diode mathematical model of a solar cell and the necessary control algorithms.
The main part of this thesis is the presentation of the design process in Chapter 3 which is based on the ground knowledge laid out in the previous chapter. First, I start with the implementation of separate models for the two sides of a double-stage PV system: the PV side and the grid side. This allows the investigation of the sides independently of the other. Finally, the complete PV system model is proposed.
In Chapter 4, a simulation study of the implemented models is presented. The results verify the basic operation of the proposed system but a number of issues are highlighted as well. The results and the experienced issues are summarized in Chapter 5, where opportunities for possible continuations are also discussed.