Solid-state switch-mode rectification converters have reached a matured level for improving power quality in terms of power-factor correction (PFC), reduced total harmonic distortion at input AC mains and precisely regulated DC output in buck, boost, buck-boost and multilevel modes with unidirectional and bidirectional power flow. This paper deals with a comprehensive review of improved power quality converters (IPQCs) configurations, control approaches, design features, selection of components, other related considerations, and their suitability and selection for specific applications. It is targeted to provide a wide spectrum on the status of IPQC technology to researchers, designers and application engineers working on switched-mode AC-DC converters. A classified list of more than 450 research publications on the state of art of IPQC is also given for a quick reference.

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A review of single-phase improved power quality AC-DC converters

A system and method for variable power transfer in an inductive charging or power system. In accordance with an embodiment the system comprises a pad or similar base unit that contains a primary, which creates an alternating magnetic field. A receiver comprises a means for receiving the energy from the alternating magnetic field from the pad and transferring it to a mobile device, battery, or other device. In accordance with various embodiments, additional features can be incorporated into the system to provide greater power transfer efficiency, and to allow the system to be easily modified for applications that have different power requirements. These include variations in the material used to manufacture the primary and/or the receiver coils; modified circuit designs to be used on the primary and/or receiver side; and additional circuits and components that perform specialized tasks, such as mobile device or battery identification, and automatic voltage or power-setting for different devices or batteries.

System and method for inductive charging of portable devices

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

In this paper, the principle of modularity is used to derive the different multilevel voltage and current source converter topologies. The paper is primarily focused on high-power applications and specifically on high-voltage dc systems. The derived converter cells are treated as building blocks and are contributing to the modularity of the system. By combining the different building blocks, i.e., the converter cells, a variety of voltage and current source modular multilevel converter topologies are derived and thoroughly discussed. Furthermore, by applying the modularity principle at the system level, various types of high-power converters are introduced. The modularity of the multilevel converters is studied in depth, and the challenges as well as the opportunities for high-power applications are illustrated.

Modular Multilevel Converters for HVDC Applications: Review on Converter Cells and Functionalities

This paper reviews the state of the art of field- programmable gate array (FPGA) design methodologies with a focus on industrial control system applications. This paper starts with an overview of FPGA technology development, followed by a presentation of design methodologies, development tools and relevant CAD environments, including the use of portable hardware description languages and system level programming/design tools. They enable a holistic functional approach with the major advantage of setting up a unique modeling and evaluation environment for complete industrial electronics systems. Three main design rules are then presented. These are algorithm refinement, modularity, and systematic search for the best compromise between the control performance and the architectural constraints. An overview of contributions and limits of FPGAs is also given, followed by a short survey of FPGA-based intelligent controllers for modern industrial systems. Finally, two complete and timely case studies are presented to illustrate the benefits of an FPGA implementation when using the proposed system modeling and design methodology. These consist of the direct torque control for induction motor drives and the control of a diesel-driven synchronous stand-alone generator with the help of fuzzy logic.

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FPGA Design Methodology for Industrial Control Systems—A Review

The goal of this paper is to propose and describe a control circuit to drive DC/DC converters. This circuit is applicable to many classic PWM topologies, QRC, MRC and resonant converters, and also to some variants of these classic topologies. The circuit proposed has been made with surface mounting techniques (SMD) and allows control of topologies of one or two transistors, working at constant frequency (PWM) or variable frequency (constant on-time or off-time). Furthermore, it allows generation of two driving signals shifted 180/spl deg/, applicable to typical topologies such as push-pull, half-bridge or full-bridge, as well as to generate complementary signals with adjustable delays, for topologies with demagnetization network, or half-bridge or full-bridge converters with complementary control.

Control circuit for DC/DC converters

One of the most critical and time consuming tasks in power electronics is the design and testing of regulators used in the compensation of switching power converters. Methods of trial and error are frequently applied to small signal regulator design. In these methods, relative stability indicators are not specified, and in general assintotical approximations are make over the frequency domain transfer functions. Because of the complexity level of the switching power converters that are discrete circuits, many difficulties are encountered in the design and testing of these devices. In this paper, the authors propose a design procedure that uses the behavioral averaged PWM switch (BAPS) results and a computer program for the automatic generation of regulator prototypes, that make easy the theoretical design and simulation of closed-loop switching power converters.

Test and design of switching mode regulators using the behavioral averaged PWM switch and a program for automatic regulator prototype generation

The energy demand of future computing gives rise to new challenges in high current voltage regulator modules (VRMs). This paper reviews the recent development in architecture and magnetics for 48-V VRMs, with a focus on achieving high efficiency, high power density, high control bandwidth, and compact system packaging. The strengths and weaknesses of many representative solutions are compared. We highlight the key opportunities and challenges and present comprehensive co-design guidelines for 48-V VRM architecture and magnetics.

J.A. Cobos

Papers

Control circuit for DC/DC converters

Test and design of switching mode regulators using the behavioral averaged PWM switch and a program for automatic regulator prototype generation

Design Considerations for 48-V VRM: Architecture, Magnetics, and Performance Tradeoffs