Integrated series active filter for aerospace flight control surface actuation

The paper investigates integrated series active filters to satisfy aircraft power quality benchmarks and underlying design compromises. Advantages include reduced component count and retrofitting capability. Further insights into the merits of the proposed solution are included, along with representative results from a prototype system

Methodologies for the design of LCC voltage-output resonant converters

Abstract: The paper presents five structured design methodologies for third-order LCC voltage output resonant converters. The underlying principle of each technique is based on an adaptation of a FMA equivalent circuit that accommodates the nonlinear behaviour of the converter. In contrast to previously published methods, the proposed methodologies explicitly incorporate the effects of the transformer magnetising inductance. Furthermore, a number of the methodologies allow the resonant-tank components to be specified at the design phase, thereby facilitating the use of standard off-the-shelf components. A procedure for sizing the filter capacitor is derived, and the use of error mapping, to identify parameter boundaries and provide the designer with a qualitative feel for the accuracy of a proposed converter design, is explored

Design Space Evaluation for Resonant and Hard-charged Switched Capacitor Converters

USB Power Delivery enables a fixed ratio converter to operate over a wider range of output voltages by varying the input voltage. Of the DC/DC step-down converters powered from this type of USB, the hard-charged Switched Capacitor circuit is of interest to industry for its potential high power density. However implementation can be limited by circuit efficiency. In fully resonant mode, the efficiency can be improved while also enabling current regulation. This expands the possible applications into battery chargers and eliminates the need for a two-stage converter.In this work, the trade-off in power loss and area between the hard-charged and fully resonant switched capacitor circuit is explored using a technique that remains agnostic to inductor technology. The loss model for each converter is presented as well as discussion on the restrained design space due to parasitics in the passive components. The results are validated experimentally using GaN-based prototype converters and the respective design spaces are analyzed

Study and design of topologies and components for high power density DC-DC converters

Size reduction of low power electronic DC–DC converters is a topic of major interest for power electronics which requires the study and design of circuits and components working under redefined requirements. For this purpose, novel circuital topologies provide advantages in terms of power density increment, especially where a single chip design is feasible. These concepts have been applied to design and implement an integrated high step-down multiphase buck converter and to study the miniaturization of a stackable fiflyback architecture. Particular attention has been dedicated to power inductors, focusing on the modeling and measurement of magnetic materials’ hysteresis and core losses

High reliability megawatt transformer/rectifier

The goal of the two phase program is to develop the technology and design and fabricate ultralightweight high reliability DC to DC converters for space power applications. The converters will operate from a 5000 V dc source and deliver 1 MW of power at 100 kV dc. The power weight density goal is 0.1 kg/kW. The cycle to cycle voltage stability goals was + or - 1 percent RMS. The converter is to operate at an ambient temperature of -40 C with 16 minute power pulses and one hour off time. The uniqueness of the design in Phase 1 resided in the dc switching array which operates the converter at 20 kHz using Hollotron plasma switches along with a specially designed low loss, low leakage inductance and a light weight high voltage transformer. This approach reduced considerably the number of components in the converter thereby increasing the system reliability. To achieve an optimum transformer for this application, the design uses four 25 kV secondary windings to produce the 100 kV dc output, thus reducing the transformer leakage inductance, and the ac voltage stresses. A specially designed insulation system improves the high voltage dielectric withstanding ability and reduces the insulation path thickness thereby reducing the component weight. Tradeoff studies and tests conducted on scaled-down model circuits and using representative coil insulation paths have verified the calculated transformer wave shape parameters and the insulation system safety. In Phase 1 of the program a converter design approach was developed and a preliminary transformer design was completed. A fault control circuit was designed and a thermal profile of the converter was also developed

Burden resistor selection in current transformers for low power applications

In order to sense AC current with electric isolation in high frequency switching power converters the most simple and low cost solution is to consider a current transformer with a burden resistor. But burden resistor selection is not a simple task because involves a lot of considerations that affect the output voltage and its signal-to-noise ratio and the bandwidth of the measure. In this paper, considering the basic equations of the transformer and applying the Laplace Transformation is obtained a simple model of the current transformer interesting to select burden resistor and even to design the current transformer in case of high frequency applicationsPostprint (published version

GAN-BASED POINT-OF-LOAD CONVERTERS FOR DATA CENTER APPLICATIONS

The growth of the information technology sector has increased demand for high-density, high-efficiency point-of-load (POL) converters. As industry continues to demand an increase in server processing power, high-current operation presents challenges to designing high-efficiency POL converters. Increased conduction and overlap losses induce significant power losses in high-power modes. The introduction of Gallium-Nitride (GaN) switching devices and the implementation of zero-current-switching (ZCS) topologies for POL applications have the potential to improve converter efficiency while maintaining or surpassing the industrial power density standard. This thesis addresses the challenges presented by high-current operation by demonstrating an accurate power loss model of the quasi-resonant zero-current-switching (QR-ZCS) buck converter and presents a comparison between the synchronous buck and QR-ZCS buck in a 5-1.8 V POL application

Solid-State Transformers for Interfacing Solar Panels to the Power Grid: An Optimum Design Methodology of a High Frequency Transformer for dc-dc Converter Applications

Nowadays the use of power electronic interfaces to integrate distributed generation with the power grid is becoming relevant due to the increased penetration of renewable energy sources like solar, and the continued interest to move to a smarter and more robust electric grid. Those interfaces, which also provide a voltage step-up or step-down function, are of particular interest because renewable energy sources do not always have voltages compatible with the connecting grid. Among them, the so-called “power electronic transformer” or “solid-state transformer” (SST) is the focus of significant research. Advantages such as bidirectional power flow, improved system control, reduced size, and premium power quality at the output terminals, increase the interest of the SST for future electric grids. The SST consists mainly of two components: a high-frequency transformer (made out of advanced magnetic materials) and power converters (employing efficient power semiconductor devices like those based on silicon carbide (SiC)) to enable operation at frequencies higher than the grid frequency. This paper presents an optimum design method that can be employed to build a high-frequency transformer for a SST intended to interface a renewable energy source (e.g., a photovoltaic system) to the electric grid. Core material, geometry, and size will be analyzed in order to provide an optimum balance between cost, efficiency, thermal management, and size. Special consideration will also be given to the selection of the winding conductors given the skin effect associated with operation at high frequencies