Cercetări privind optimizarea modulelor electronice de alimentare / Research on optimization of electronic power modules

The improvement of the magnetic materials properties, in relation with the new technologies, creates a strong link with the constant tendency of dimensional reduction of the devices that need to be supplied. The thesis subject is more like a set of investigations on several factors that reduce the energy efficiency of planar structures. In this work several aspects are taking into consideration and they are: the energy stored in the loss inductance between windings, the distribution of current density in windings as a consequence of the magnetic component shape, the induction distribution as a function of amplitude and frequency, the ratio between losses in transformer windings and the PCB structure and nevertheless, the influence of the waveform over the magnetic core losses. Experimental result have been obtained in which the thermal effect has been revealed. The thesis also contains results that have been achieved by developing an experimental DC to DC converter that uses planar magnetics. A 1,5 MHz PWM controller was used for the converter platform. Another aspect that can be found in the thesis is the influence of the excitation waveform over the hysteresis loop of the magnetic core.