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

This paper describes a new way to increase the efficiency and to reduce the size and cost in power factor correctors with fast regulation of the output voltage by integration of power factor corrector and DC/DC regulator in the rectifier with only one control stage. With this converter, a high power factor and a tight regulated output voltage are achieved. The proposed converter has advantages such as efficiency and size over the two stage structure, and simplicity over other single stage solutions. Experimental results and design consideration are presented.

A single-stage rectifier with PFC and fast regulation of the output voltage

Simulation can play an important role in the configuration, analysis and design of distributed power systems, but the lack of available models of the main components (batteries, fuel-cells, AC-DC and DC-DC converters) is a major drawback for its use. The aim of this work is to develop a generic model of multi-output DC-DC converters, widely used in power electronic systems, based on the information provided by manufacturers in their datasheet or measurements. The model is intended to be able to predict power consumption, efficiency, system stability and large signal behavior including cross-regulation, inrush current, protections, start-up and remote on-off control.

Behavioral modeling of multi-output DC-DC converters for large-signal simulation of distributed power systems

A new strategy to accomplish low-frequency Regulation EN 61000-3-2 at system level is proposed in this paper. By means of a simple converter, connected in parallel with the loads, the harmonic currents generated by them are greatly reduced, it being unnecessary to include additional power-factor-correction converters. This approach is based on the well-known parallel active power filters, but the difference is that it is placed on the DC side. Its position, at the rectified line voltage, produces some important advantages such as a simple power stage, a simple analog control, and flexibility in the design of the system. Moreover, this converter features high efficiency and small size. The experimental results show the benefits of this solution.

Harmonic reducer converter

Standard IEC 1000-3-2 imposes limits to low frequency harmonic currents generated by electronic equipment connected to AC mains Off-line power supplies have to be re-designed to comply with this normative The impact is a higher cost and volume of these power supplies Simple single-stage AC/DC converters with fast output voltage regulation are presented in this paper With a single switch and single control loop the converters comply with the Standard IEC 1000-3-2 for a medium power range (500 W) The main difference of this proposal with the state of the art is that the voltage on the storage capacitor is clamped, being possible to use this converter in universal input voltage applications In addition, these converters show advantages from the point of view of size and cost Experimental results are included in the paper

Simple AC/DC converters to meet IEC 1000-3-2

The application of interleaving techniques is a very common practice in the construction of transformers for electronic circuits, in order to reduce the AC resistance and leakage inductance. However, the effects of the interleaving techniques on the capacitive effects is not so well known. This work presents a study of the quantification of the benefits that can be achieved applying interleaving techniques between different layers (interlayer effect) and in the same layer (intralayer effect). The sensitivity of the leakage inductance, AC resistance and capacitive effects is studied in this work. Some design guidelines are extracted in order to select the best winding strategy for each transformer. The analysis has been carried out by means of finite element analysis (FEA) techniques in order to take into account all the frequency and geometry effects.

J.A. Cobos

Papers

A single-stage rectifier with PFC and fast regulation of the output voltage

Behavioral modeling of multi-output DC-DC converters for large-signal simulation of distributed power systems

Harmonic reducer converter

Simple AC/DC converters to meet IEC 1000-3-2

Taking into account all the parasitic effects in the design of magnetic components