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Due to their superior material properties, wide bandgap (WBG) semiconductors enable the application of power electronics at higher temperature operation, higher frequencies, and higher efficiencies compared to silicon (Si). However, the commonly-used aluminum wire bonding as topside interconnection technology prevents WBG semiconductors from reaching their full potential, due to inherent parasitic inductances, large size, heat dissipation, and reliability issues of wire bonding technology. Therefore, this article presents a comprehensive review of topside interconnection technologies of WBG semiconductor power devices and modules. First, the challenges and driving factors for the interconnection of WBG semiconductor dies are discussed. Second, for each widely commercially used WBG semiconductor, i.e., silicon carbide and gallium nitride, technical details and innovative features of state-of-the-art interconnection techniques in packages are reviewed. Then, the majority of existing topside interconnection materials for WBG semiconductors are categorized and compared, followed by a discussion of their advantages, challenges, and failure modes. Based on this elaborate discussion, potential future directions of the interconnection technology development are given. It is concluded that the superior performance of WBG semiconductors can be obtained by combining novel materials with innovative designs for the topside interconnections. [ABSTRACT FROM AUTHOR]

Diesel generators in small electricity grids are mostly not used in a very efficient way. The reason for this is twofold. First of all, the efficiency of a diesel generator is dependent on the ratio determined by the average power divided by the peak power of the generator. The smaller this ratio is, the lower the efficiency. Furthermore, some loads can regenerate energy. In small grids, this energy is mostly not needed elsewhere and should be dissipated. A solution solving both problems previously mentioned is using an energy storage device in the system. This storage can be used for peak shaving and storing regenerated energy. This paper focuses on a generator-set with energy storage. Six different power management strategies are discussed. Calculation of the costs shows that adding an energy storage device lowers the cost for all methods. Verification with simulation and experiments has been carried out. Index Terms--Costs, diesel-driven generators, energy conservation, energy storage, lithium-ion battery, power electronics, supercapacitor.

In this paper, the possibility of reaching high power densities in multikilowatt dc-dc converters with galvanic isolation is demonstrated and the main design issues are discussed. The issues related to converter topology, transformer design, and thermal management are addressed, and new conceptual solutions are proposed. Implementing zero-voltage-switching quasi-zero-current-switching topology, optimized transformer design with leakage layer, and thermal management based on conduction enhanced by heat pipes at critical places resulted in very high power density and efficiency. The power density reached by the converter prototype is 11.13 kW/L with water cooling and 6.6 kW/L with air cooling. In the same time, the measured efficiency exceeded 97% in a broad load range. The new design concepts are demonstrated on a 50-kW converter prototype that was successfully tested at full-load conditions. Index Terms--DC-DC converter, galvanic isolation, high-frequency transformer, high power density, thermal management.

In this paper, a very high power density dc/dc converter module for automotive applications is investigated. The 14-V/42-V converter is specified to operate at a power level of 2.1 kW with a water cooled heat sink at 85[degrees]C. The design and implementation of very high density passive components are discussed. Using the results of the passive component design, a prototype converter is built, achieving a final power density of 170 W/[in.sup.3]. The thermal performance of the passive components and the converter module under different electrical and thermal excitations is investigated and recorded. Results are presented over the full excitation range. Index Terms--Converter module, thermal performance.

Passive components, and inductors, in particular, contribute greatly to the overall volume of power electronic converters. These components are normally packaged individually with little concern for the overall system. For high-density switching power supplies it is imperative to minimize the volume to as great an extent as possible which implies that the passive component volume usage needs to be improved. This can be accomplished by applying suitable packaging and cooling techniques to these components. In this paper, two inductor structures finding application in a 2.1-kW synchronous automotive converter are described. The air-gap placement, losses, cooling methods, and thermal profiles are analyzed and verified experimentally with an inductor designed for operation at 85[degrees]C ambient. Index Terms--Direct heat removal, high power density, high temperature, indirect heat removal, packaging, passive component.

This paper covers the experimental investigation and theoretical calculation of losses in a planar inductor under load. Finite-element software is used to perform the loss calculations. Thermally controlled experiments are performed for a range of frequencies to validate the corresponding finite-element method loss calculations. The thermal dependence of the loss mechanisms is also considered. Index Terms--Finite-element method (FEM) calculations, loss analysis, loss measurement, planar inductor, thermal measurement.

The layout of a capacitor bank with clamping diodes is investigated based on an experimental 5.5-kJ energy storage unit for pulsed power applications. While the current sharing between parallel-connected capacitors is good, it is not the case with parallel-connected clamping diodes. Despite a very-low-inductance busbar and attention to symmetrical layout, unequal current sharing results. Good agreement was obtained between measured waveforms and a detailed simulation model. The simulation model indicated that the unequal current sharing is due to small differences between the coupling factors of the parasitic busbar inductances near the capacitors at the ends and at the middle of the bank. It is concluded that the best solution is to place the parallel diodes as close as possible to each other at a position where best averaged coupling is achieved with the individual capacitors of the bank. Index Terms--Current sharing, high-frequency busbar, pulsed power, resonant forced commutation.

The low-pass filter (LPF) is a fundamental component of many power electronic systems, for example, the output filters of dc-to-dc converters. The volume of the two components that constitute the LPF contribute a majority of the final system's volume, thus affecting the overall power density of the system. To be able to reach the high power densities that are required nowadays, the packaging of these components needs to be addressed. A new packaging approach is considered where the main criteria is to increase the packaging density of the LPF. The filter is considered volumetrically, and the minimum possible volume is derived. The construction and losses of such a filter are also discussed. Index Terms--Energy density, high-density packaging, loss distribution, low-pass filter, shield, volumetric optimization.

Design and optimization of high-frequency magnetic components usually involve a number of tradeoffs between performance functions. This paper investigates the relationships between some of these factors by direct implementation of the thermal reference model previously presented by the authors. This unique thermal model provided the foundation for a more flexible approach to design and optimization, forcing uninterrupted coherence between electromagnetic behavior and predefined thermal conditions. Generic scaling of transformer parameters is performed herein, under simultaneous control of the temperature rise. Relationships for performance functions, such as maximum power rating, power density, total losses, efficiency, and leakage impedance are determined, tabulated, and plotted as functions of several different scaling conditions. Index Terms - Design, high-frequency power transformers, magnetic components, optimization, scaling, thermal models.

A new thermal model is introduced which is based on unique references, specifically suited to design and optimization of high-frequency high-power magnetic components. This thermal reference model is independent of shape, size, and orientation, so that a general set of data may be used to optimize transformer structure. The model, its limitations, and applications are described in detail. Unique measurement techniques are used for experimental verification and empirical sets of practical reference data, which are also provided. Index Terms - Design, high-frequency power transformers, magnetic components, optimization, thermal models.

Integrated inductor--capacitor-transformer L-C-T technology has been the subject of research over the last few years. Research into producing optimum design equations has been conducted. To determine some of the physical and technological limitations of the integrated L-C-T technology, a 1-kW 1-MHz resonant dc-dc converter was designed and built. The design was limited only by in-house material, construction, and technological restrictions. Through this process, it is hoped that some of the current technological limitations can be quantified. The design and construction process is given, while some of the limits of this technology are derived from experimental results. Index Terms--Hybrid converters, integrated capacitance-inductance, passive integration, resonant converters.

Capacitors are utilized in a variety of different ways in power electronic circuits. Typical applications are in snubber, clamping, and resonant circuits. For design purposes, it is necessary to make an accurate measurement of the actual behavior of the capacitance that is added to the circuit under conditions related to those prevailing in a converter. For this purpose, a number of different measurement systems or techniques can be utilized. Four of these measurement systems are compared. These are small-signal variable-frequency measurement, large-signal quasi-dc measurement, in--situ high-voltage measurement, and small-signal with large dc bias voltage measurement. Each of these measurement techniques returns characteristic values based on its particular model of the test capacitor. These tests are done on both ceramic and nonceramic capacitors at room temperature. The results are discussed. Index Terms--Capacitor measurement, dielectric measurement, in--situ measurement, large-signal measurement.

This paper deals with a generic methodology to evaluate the magnetic parameters of contactless power transfer systems. Neumann's integral has been used to create a matrix method that can model the magnetics of single coils (circle, square, rectangle). The principle of superposition has been utilized to extend the theory to multi-coil geometries, such as double circular, double rectangle and double rectangle quadrature. Numerical and experimental validation has been performed to validate the analytical models developed. A rigorous application of the analysis has been carried out to study misalignment and hence the efficacy of various geometries to misalignment tolerance. The comparison of single-coil and multi-coil inductive power transfer systems (MCIPT) considering coupling variation with misalignment, power transferred and maximum efficiency is carried out. [ABSTRACT FROM AUTHOR]