Aneta Hapka

The thermally induced limitations of SiC SBDs operation conditions

In the paper, the DC current-voltage characteristics of silicon carbide Schottky barrier diodes are analyzed, with special attention paid to the critical current and junction temperature estimation. The self-heating phenomenon, interpreted as an electro-thermal positive feedback, is taken into account. The measurements of isothermal and non-isothermal I-V characteristics, as well as adequate calculations, are shown and discussed. The electro-thermal models, based on various descriptions of temperature-dependent series resistance of the device, are proposed. It is also shown that the shapes of I-V characteristics depend on the current range and on the heat-sink size.

A System for Cooling Electronic Elements with an EHD Coolant Flow

A system for cooling electronic components where the liquid coolant flow is forced with ion-drag type EHD micropumps was tested. For tests we used isopropyl alcohol as the coolant and CSD02060 diodes in TO-220 packages as cooled electronic elements. We have studied thermal characteristics of diodes cooled with EHD flow in the function of a coolant flow rate. The transient thermal impedance of the CSD02060 diode cooled with 1.5 ml/min EHD flow was 7.8°C/W. Similar transient thermal impedance can be achieved by applying to the diode a large RAD-A6405A/150 heat sink. We found out that EHD pumps can be successfully applied for cooling electronic elements.

Synteza transmitancji operatorowej bloku sterowania przetwornicą BUCK z kompensacją indukcyjności pasożytniczej kondensatora

The article presents the synthesis of transfer function of BUCK converter control system. The obtained s-transmittance ensures compensation of the influence of the parasitic inductance of the output capacitor on the time waveforms in the system. The proposed solution eliminates the occurrence of output voltage oscillation arising after step changes in the input voltage and current in the load. (Synthesis of the transfer function of control block for BUCK converter with compensation of capacitors parasitic inductance) Słowa kluczowe: przekształtniki mocy, przetwornica typu BUCK, efekty pasożytnicze, sterowanie cyfrowe, symulacje stanów przejściowych.

Symulacje PSPICE przetwornicy BUCK oparte o modele uśrednione

The article presents examples of applications of averaged models in PSPICE simulations of power converters. The results of simulation of transients in the BUCK converter and its frequency characteristics are shown. A comparison of the results obtained for the complete model (a pair of switches and PWM generator) and largeand small-signal averaged models has been performed. (PSPICE simulations of BUCK converter, based on average models). Słowa kluczowe: przekształtniki mocy, przetwornica typu BUCK, modele uśrednione, PSPICE, symulacje stanów przejściowych, charakterystyki częstotliwościowe.

Influence of operation conditions on true-static DC characteristics and on electro-thermal transient states in silicon carbide Merged PiN Schottky diodes.

In this paper, measured and calculated non-isothermal DC characteristics of silicon carbide MPS devices are investigated, with special attention paid on critical parameters, such as maximum current and junction temperature at which a thermal runaway may occur. Electro-thermal transient states in single MPS devices (forward surge current tests) and in the simple Greatz rectifier are simulated and compared to measurements. Various electro-thermal models of SiC SBDs, with a simplified, effective procedure for calculations of junction temperature are proposed.