http://ieeexplore.ieee.org/iel5/5610941/5624686/05624745.pdf

Power electronics

Wide bandgap semiconductors show superior material properties enabling potential power device operation at higher temperatures, voltages, and switching speeds than current Si technology. As a result, a new generation of power devices is being developed for power converter applications in which traditional Si power devices show limited operation. The use of these new power semiconductor devices will allow both an important improvement in the performance of existing power converters and the development of new power converters, accounting for an increase in the efficiency of the electric energy transformations and a more rational use of the electric energy. At present, SiC and GaN are the more promising semiconductor materials for these new power devices as a consequence of their outstanding properties, commercial availability of starting material, and maturity of their technological processes. This paper presents a review of recent progresses in the development of SiC- and GaN-based power semiconductor devices together with an overall view of the state of the art of this new device generation.

A Survey of Wide Bandgap Power Semiconductor Devices

High-frequency-link (HFL) power conversion systems (PCSs) are attracting more and more attentions in academia and industry for high power density, reduced weight, and low noise without compromising efficiency, cost, and reliability. In HFL PCSs, dual-active-bridge (DAB) isolated bidirectional dc-dc converter (IBDC) serves as the core circuit. This paper gives an overview of DAB-IBDC for HFL PCSs. First, the research necessity and development history are introduced. Second, the research subjects about basic characterization, control strategy, soft-switching solution and variant, as well as hardware design and optimization are reviewed and analyzed. On this basis, several typical application schemes of DAB-IBDC for HPL PCSs are presented in a worldwide scope. Finally, design recommendations and future trends are presented. As the core circuit of HFL PCSs, DAB-IBDC has wide prospects. The large-scale practical application of DAB-IBDC for HFL PCSs is expected with the recent advances in solid-state semiconductors, magnetic and capacitive materials, and microelectronic technologies.

Overview of Dual-Active-Bridge Isolated Bidirectional DC–DC Converter for High-Frequency-Link Power-Conversion System

DC–DC converters with voltage boost capability are widely used in a large number of power conversion applications, from fraction-of-volt to tens of thousands of volts at power levels from milliwatts to megawatts. The literature has reported on various voltage-boosting techniques, in which fundamental energy storing elements (inductors and capacitors) and/or transformers in conjunction with switch(es) and diode(s) are utilized in the circuit. These techniques include switched capacitor (charge pump), voltage multiplier, switched inductor/voltage lift, magnetic coupling, and multistage/-level, and each has its own merits and demerits depending on application, in terms of cost, complexity, power density, reliability, and efficiency. To meet the growing demand for such applications, new power converter topologies that use the above voltage-boosting techniques, as well as some active and passive components, are continuously being proposed. The permutations and combinations of the various voltage-boosting techniques with additional components in a circuit allow for numerous new topologies and configurations, which are often confusing and difficult to follow. Therefore, to present a clear picture on the general law and framework of the development of next-generation step-up dc–dc converters, this paper aims to comprehensively review and classify various step-up dc–dc converters based on their characteristics and voltage-boosting techniques. In addition, the advantages and disadvantages of these voltage-boosting techniques and associated converters are discussed in detail. Finally, broad applications of dc–dc converters are presented and summarized with comparative study of different voltage-boosting techniques.

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Step-Up DC–DC Converters: A Comprehensive Review of Voltage-Boosting Techniques, Topologies, and Applications

Energy storage systems (ESSs) are enabling technologies for well-established and new applications such as power peak shaving, electric vehicles, integration of renewable energies, etc. This paper presents a review of ESSs for transport and grid applications, covering several aspects as the storage technology, the main applications, and the power converters used to operate some of the energy storage technologies. Special attention is given to the different applications, providing a deep description of the system and addressing the most suitable storage technology. The main objective of this paper is to introduce the subject and to give an updated reference to nonspecialist, academic, and engineers in the field of power electronics.

Energy Storage Systems for Transport and Grid Applications

As utilities face increasing fault currents in their systems as a result of increasing demand and/or deployment of new technologies, fault current limiters promise a solution that will mitigate the need for replacing existing breakers as well as being a general protective device for elements connected to the grid. This paper describes some recent advances in semiconductor-based fault current limiting technology including both the more mature silicon developments along with early developments using silicon carbide. The capabilities and limitations of these technologies are compared and contrasted. Some example scenarios of FCLs have been analyzed and are briefly described along with advanced features that semiconductor FCLs may bring to the solution space.

Solid-state fault current limiters: Silicon versus silicon carbide

The requirements on volumetric density of power electronic converters in electric vehicles are increasing, since more space is needed for electronic systems and passenger capacity. The U.S. Department of Energy (DOE) has set the 2020 target for vehicular power electronic systems as 13.4 kW/l. Achieving high power density using commercial off-the-shelf (COTS) parts is challenging because these components have various form factors leading to unused spaces, as well as cooling and airflow issues. In this work, a high-power-density traction inverter, rated at 50-kW with the peak power at 74-kW, is designed and built using all COTS components. The system is tested under resistive-inductive loads and a dynamometer-based driving schedule. A power density of 13.64 kW/l was accomplished and possibilities for volume reduction to achieve 25 kW/l are evaluated revealing the challenges to achieve even higher power densities using COTS technologies.

A Compact 50-kW Traction Inverter Design Using Off-the-Shelf Components

Low-pass filter inductors are widely used in grid-connected power electronic converters. Different magnetic core materials are available for building these inductors. In this paper, the design of an inductor for an industrial-scale 1 MVA high-power three-phase ac-dc converter is reported. Selection of the core material, which depends on trading off between several aspects, is described. Instead of the traditional fixed inductance value for a large current range, the powder core inductor has a nonlinear inductance characteristic which is inversely proportional to the magnetic excitation. The benefits of using this variable inductance characteristic are described and verified by both circuit and magnetic simulation tools. A hardware prototype was built and initial experimental results are illustrated.

Realization of high-current variable AC filter inductors using silicon iron powder magnetic core

The main objective of this research work is to develop a new low-cost isolated three-level ac–dc power converter topology with a reduced number of switches. Existing three-level converter topologies change ac power to dc power while maintaining requirements set by international standards for power conversion. These types of converters have significant conduction losses due to high currents in the low-voltage side and high costs, mainly when using several active devices in series or in parallel to achieve high-voltage and high-power levels. The proposed topology replaces the conventional three-level converters in the secondary side by only two controlled devices and four diodes while still maintaining the basic functionality of a three-level converter. Furthermore, simulation results for a 25-kW case study and experimental results on a 900-W scale-down prototype demonstrate the feasibility of the proposed ideas.

/pdf/a-three-level-isolated-ac-dc-pfc-power-converter-topology-4d3bwogvde.pdf

A Three-Level Isolated AC–DC PFC Power Converter Topology With a Reduced Number of Switches

Manufacturers of power electronic converters seek to increase not only power and voltage ratings but also power density. Inductorless converters help achieve the latter because capacitive energy storage has higher energy density than inductive energy storage. Multilevel topologies, which include some inductorless topologies, enable converters to operate at higher voltage levels by allowing voltage sharing between devices. This paper presents a novel multilevel inductorless boosting three-phase inverter that is constructed using a series configuration of switched-capacitor converter cells. This allows for the inverter to be used without an additional boost converter or output transformer when powered from a low-voltage dc source, such as the battery of a grid-connected energy storage system or an electric vehicle.

Juan Carlos Balda

Papers

Solid-state fault current limiters: Silicon versus silicon carbide

A Compact 50-kW Traction Inverter Design Using Off-the-Shelf Components

Realization of high-current variable AC filter inductors using silicon iron powder magnetic core

A Three-Level Isolated AC–DC PFC Power Converter Topology With a Reduced Number of Switches

Implementation of a three-phase multilevel boosting inverter using switched-capacitor converter cells