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In this paper, on-state dynamic drain source resistance (R DS(ON) ) phenomenon in GaN based power switches is analyzed. Dynamic R DS(ON) may increase the power losses in converters, thus reducing the benefits of using GaN power devices in this field. The operating parameters having an impact on dynamic R DS(ON) are investigated by analyzing the research works available so far from industry and academia. The objective of this work is to highlight the key operating parameters that influence this phenomenon, in order to give useful information to designers. Another objective is the identification of the lack of information on the topic, thus suggesting the analysis useful for an all-embracing understanding of the influence on dynamic R DS(ON) due to the different operating conditions. To these aims, the collected data are harmonized since the variety of test conditions, the different methods adopted to report the results and to obtain them. The comparison has highlighted that the working frequency is the main factor influencing the dynamic R DS(ON) . Moreover, the analysis has drawn attention to the necessity to make extensive experimental analyses on various technologies types and mission profiles. Finally, the main research topic to be properly investigated concerns the deep analysis of the correlations among the parameters which affect the dynamic R DS(ON) .

The main aim of this work is to provide a straightforward tool to modelize the thermal behavior of power module packages. The proposed circuit-based modeling approach takes into consideration the mutual thermal interaction among the dies, which plays a key role in the estimation of their working temperature. Furthermore, this modeling method features a compact and modular structure that can be easily tailored for different package configurations, maintaining limited complexity and computational burden. Last but not least, this thermal model includes both heating and cooling effects, thus allowing to evaluate thermal stresses even under pulse width modulated power devices. The thermal model is obtained starting from the temperature profiles carried out through a finite element analysis (FEA), by applying a power loss step to each single die. Starting from these profiles, a fitting curve algorithm is used to identify the elements of the RC networks used to represent the auto and mutual thermal impedances. The thermal model is thus an algebraic linear system including the RC networks parameters, and it can be exploited to identify the thermal status of each die of the power module even operating at different load conditions. The method has been applied in a SiC 3 phase inverter power module in which the high side and low side switches are formed with four parallel connected 1200V 350A SiC MOSFET dies. The results outgoing from the proposed model are confirmed by that carried out from FEA.

Power device modeling plays an important role at the design stage of power conversions systems, especially in the automotive and aircraft sectors. In this context, it is important to obtain in short time an accurate model that account for the mutual interaction of thermal and electrical quantities. The behavioral model is the best approach because it consists of a set of equations that emulates the device behavior at terminals level and can be easily implemented in a SPICE simulation tool, largely adopted both in industrial and academic contexts. The major issue of the behavioral model is to choose the equations parameters such that the simulations results fit the measurement data. In this paper, this problem is tackled by means of a particle swarm optimization algorithm. It is applied to automatically find the optimal parameters for an accurate behavioral model of an automotive grade SiC MOSFET that properly fits the datasheet curves. The comparison between the waveforms obtained by experimental tests and the SPICE simulations in a double test has confirmed the accuracy of the model.

There is an increasing interest in developing unmanned aerial vehicles (UAVs) for small size objects delivering. The efficiency and cost of the on board power converters are important aspects for their rapid spreading. Moreover, lifetime, safety, and reliability of the converter in the powertrain are crucial. In this perspective, voltage overshoots and oscillations due to the parasitic phenomena are important stresses to be cared. In this work, their effects in a half bridge converter have been analyzed since it can represent a leg of a three phase inverter feeding a motor of the UAV. Automotive grade super junction (SJ) MOSFET has been considered because it presents high reliability level with increased lifetime expectancy and it is less subjected to overshoot and oscillation issues. Moreover, SJ MOSFET is a mature technology with better cost. In this paper, an extensive parametric analysis has been carried out by performing several LTspice simulations to highlight the effects of the parasitic phenomena on both the drain source-voltage and efficiency. The results have been firstly validated, then useful design constraints have been identified.

In this paper, a stop-band filter realized by a high impedance surface for reducing electromagnetic interference from printed circuit boards is studied. Starting from an existing high impedance surface, Design of Experiments techniques and numerical simulations were employed to analyze the effect of its geometrical parameters on the desired forbidden band-gap of the filter. Finally, an improved high impedance surface is proposed.

Today the technologies regarding the solid-state devices are in huge development. Well-established Silicon power devices in the field of the power conversion belong to several families having a large range of rated value of currents and voltages. The new entries are innovative devices exploiting the good properties of wide band gap materials, like the Silicon Carbide and the Gallium Arsenide. Industrial and academic research interests focus on the development of well-established and new devices, looking to obtain good performances and enhanced energy savings. This paper explores and discusses the application of the power devices in aviation, highlighting the crucial aspects and the challenges to deal with for a full implementation of the more electric aircraft paradigm.