StatusThe thesis was presented on the 4 February, 2011
Approved by NCAA on the 31 March, 2011
Abstract– 0.38 Mb / in romanian
– 0.34 Mb / in romanian
Dissertation contents: introduction, five chapters, general conclusions and recommendations, bibliography - 101 references, 170 pages of the main part, 5 tables and 85 figures.
Number of publications: the obtained results are published in 18 scientific papers and 2 patents.
Field of research: power electronics.
The aim of the work: research and elaboration of convenient approximation of I-V characteristics of transistors, solar cells and of a method of an estimation of efficiency of their regimes used for elaboration of power electronics devices.
The research objectives: to validate the definition of a deviation and comparison of efficiency of modes for active two-poles with linear I-V characteristics ; for active two-poles with nonlinear I-V characteristics on an example offered quasi resonant voltage converters; to develop similarity the I-V characteristics of semi-conductor devices and the offered quasi resonant voltage converter for the uniform description and calculation of power supply systems; to develop the base approach giving a wide class of dependences convenient for engineering practice for the description of the I-V characteristics of various semi-conductor devices, to develop the approximation models of the I-V characteristics of various transistors; to apply the received results to an estimation of efficiency of SC regimes.
The scientific originality of the research consists in: application of methods of projective geometry to the analysis of electric circuits regimes; a substantiation of model of the equivalent generator of the quasi resonant voltage converter as active two-pole with current selfrestriction; the base approach for obtaining a wide class of expressions for representation of various characteristics on a basis I-V characteristics an active two-pole with current selfrestriction; application and development of similarity of characteristics of the quasi resonant voltage converter and such semi-conductor devices, as transistors and SC.
The theoretic and practical value of the research consists in: application of new
mathematical apparatus in the theory of electric circuits, development of models of active twopoles,
classification of typical I-V characteristics and characteristic regimes; uniform and
validated description of characteristics and efficiency of regimes of voltage converters,
transistors and SC; simple calculation procedures (direct analytical calculation) of voltage
converters regimes, transistors and SC; techniques of an estimation of efficiency of regimes in
the form of a deviation from a mode of maximum power of SC, the voltage converter; possible
application of simple microcontrollers for the organization of a direct digital control of the power