Research related to photovoltaic panels comprises different topics starting with modelling solar cells, finding new maximum power point tracking (MPPT) algorithms, testing existing ones or designing of DC/DC converters for MPPT systems and microgrids that incorporate photovoltaic energy sources. In each of the examples above a deep knowledge of photovoltaic panels is required, as well as a reliable measurement system that can deliver continuous, stable light with enough power to meet standard test conditions (STC) and that can ensure repeatable results. Therefore this paper presents a low-cost solar simulator with a microcontroller-based measurement system, that can be used for various measurements of low-power photovoltaic panels.

The main goal of this study was to derive small-signal models of the input characteristics of buck, boost, and flyback converters working in continuous conduction mode (CCM) and discontinuous conduction mode (DCM). The models presented in the paper were derived using the separation of variables approach and included the parasitic resistances of all converter components. The paper features a discussion about the limitations of the model accuracy. The presented characteristics were obtained by calculation and verified by measurements. The input characteristics of converters are essential in the design of converters used in Power Factor Correction systems as well as in maximum power point tracking systems (MPPT).

Silicon carbide (SiC) semiconductor diodes are studied for high power and high temperature system applications. Our packaging technology is developing to ensure a working temperature above 300°C for Schottky and PIN diodes. This work presents an investigation on the thermal properties of proposed assembly of SiC die into a ceramic package. Ag micro particles and sintering process were used for the assembly. It was found that thermal resistance of such package is dependent on assembly technology and it is near 3 K/W for Schottky diode in the temperature range from room temperature up to 200°C, and the thermal resistance is in the range 10.5 ÷ 8.7 K/W for PIN diode at temperature in the range from 20°C up to 300°C.