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

Analytical (1D) thermal models for magnetic components are commonly used in the magnetic component design process in order to estimate the temperature in the component. Most of the analytical thermal models presented in the literature, consider small separation between different turns of the same layer. However, if that separation is high, a 1D thermal model might be inaccurate. This paper presents a new thermal model that is valid also for those cases. The model has been validated with several components and it has been compared with FEA results and measurements.

A new approach to obtain 1D thermal models for magnetic components including the effect of spacing between conductors

An EMI filter design procedure for power converters is proposed. Based on a given noise spectrum, information about the converter noise source impedance and design constraints, the design space of the input filter is defined. The design is based on component databases and detailed models of the filter components, including high frequency parasitics, losses, weight, volume, etc.. The design space is mapped onto a performance space in which different filter implementations are evaluated and compared. A multi-objective optimization approach is used to obtain optimal designs w.r.t. a given performance function.

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Design and multi-objective optimization of EMI input filters

Nowadays it is needed to count with small size and high efficiency power factor pre-regulator (PFP). According to the experimental results, the zero-current-switched quasi-resonant SEPIC (ZCS-QR SEPIC) used as PFP with voltage follower control seems to be a good choice to solve the problem mentioned above. This study gives the qualitative and quantitative criteria for the most favourable design of this type of PFP.

Design criteria for zero-current-switched quasi-resonant SEPIC used as power factor pre-regulator with voltage follower control

The operation of a multiphase topology, ideally, without energy storage presents the advantage of achieving very high efficiency over a wide load range as well as a fast dynamic response. However, ideal no-energy storage operation also implies a limitation in the regulation capability of the topology, the output voltage can only take discrete values. These features (high efficiency and discrete regulation capability) of the proposed energy conversion strategy enable the topology as a candidate for ‘DC-DC transformer’ applications. The advantages, drawbacks and the operating principle of this concept, implemented with a ‘closed chain’ magnetic structure have been already presented. In this work, the minimum energy storage operation, is applied to two different magnetic structures. These magnetic structures are called ‘closed chain’ and ‘pyramidal’ the main advantage of the ‘pyramidal’ coupling structure is to improve the size of the converter without increasing the operating frequency. Both magnetic structures are analyzed, compared and experimentally implemented.

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Multiphase transformer-coupled converter: Two different strategies for energy conversion

A new scheme for driving the synchronous rectifiers in the output side of DC/DC converters has the output current always flowing through a low-resistance switch, even when the input-side switch(es) are not conducting. The gate-source voltage of the synchronous-rectifier switches is independent of (instead of proportional to) the dc input voltage, therefore this scheme is especially well suited to converters that must accommodate a wide range of input voltage, e.g., >2:1. The scheme is based on two auxiliary output-side windings and additional driving circuitry (inverter + driver). To validate the concept, we designed, built, and tested a half-bridge converter for 24 Vdc to 1.5 Vdc at 10 A. The dependence of circuit operation on circuit parameters is analyzed (driver parameters, transformer coupling), and simulation and experimental results are presented.

http://ieeexplore.ieee.org/iel5/7959/22018/01023861.pdf

New driving scheme for high-efficiency synchronous rectification in wide-input-voltage-range DC/DC converter has output current always flowing through a low-resistance switch

J.A. Cobos

Papers

A new approach to obtain 1D thermal models for magnetic components including the effect of spacing between conductors

Design and multi-objective optimization of EMI input filters

Design criteria for zero-current-switched quasi-resonant SEPIC used as power factor pre-regulator with voltage follower control

Multiphase transformer-coupled converter: Two different strategies for energy conversion

New driving scheme for high-efficiency synchronous rectification in wide-input-voltage-range DC/DC converter has output current always flowing through a low-resistance switch