132 research outputs found

    Practical design and evaluation of a 1 kW PFC power supply based on reduced redundant power processing principle

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    Author name used in this publication: Martin K. H. CheungAuthor name used in this publication: Chi K. Tse2007-2008 > Academic research: refereed > Publication in refereed journalVersion of RecordPublishe

    Digital computer simulation of inductor-energy-storage dc-to-dc converters with closed-loop regulators

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    The simulation of converter-controller combinations by means of a flexible digital computer program which produces output to a graphic display is discussed. The procedure is an alternative to mathematical analysis of converter systems. The types of computer programming involved in the simulation are described. Schematic diagrams, state equations, and output equations are displayed for four basic forms of inductor-energy-storage dc to dc converters. Mathematical models are developed to show the relationship of the parameters

    Mass study for modular approaches to a solar electric propulsion module

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    The propulsion module comprises six to eight 30-cm thruster and power processing units, a mercury propellant storage and distribution system, a solar array ranging in power from 18 to 25 kW, and the thermal and structure systems required to support the thrust and power subsystems. Launch and on-orbit configurations are presented for both modular approaches. The propulsion module satisfies the thermal design requirements of a multimission set including: Mercury, Saturn, and Jupiter orbiters, a 1-AU solar observatory, and comet and asteroid rendezvous. A detailed mass breakdown and a mass equation relating the total mass to the number of thrusters and solar array power requirement is given for both approaches

    High-voltage dc power processing thermal control and packaging techniques

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    The power processor operates in several modes, delivering up to 100 amperes of regulated electrical power, operating at input voltages to 375 volts with outputs controlled by an integral microprocessor. Several alternative packaging concepts are discussed and evaluated. High-voltage design applications, power stage interconnection and EMI considerations are also discussed. Preliminary thermal analyses were performed and the results presented for each conceptual approach with parametric study results given for the selected concept

    A low noise switching converter-regulator for main power control in a space power system

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    Variable ratio dc transformer regulator used to process main vehicle power from solar array battery power system in radio astronomy explorer spacecraf

    Multiple high voltage output DC-to-DC power converter

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    Disclosed is a multiple output DC-to-DC converter. The DC input power is filtered and passed through a chopper preregulator. The chopper output is then passed through a current source inverter controlled by a squarewave generator. The resultant AC is passed through the primary winding of a transformer, with high voltages induced in a plurality of secondary windings. The high voltage secondary outputs are each solid-state rectified for passage to individual output loads. Multiple feedback loops control the operation of the chopper preregulator, one being responsive to the current through the primary winding and another responsive to the DC voltage level at a selected output

    Parallel connection of single-switch three-phase power-factor correction converters for interleaved switching

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    A circuit for the parallel connection of multiple high-frequency three-phase power-factor-correction converters is proposed which enables their input and output current ripple to be interleaved. Such interleaved operation substantially improves the composite power factor, line-current ripple and output-voltage ripple. The improvement is investigated by developing solutions to circuit state equations which allow the high-frequency content of the line current, as well as the low-order line-frequency harmonics, to be computed. Conclusions drawn from the computed results are verified experimentally using a 1 kW, two-stage, interleaved converte

    Design analysis of levitation facility for space processing applications

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    Containerless processing facilities for the space laboratory and space shuttle are defined. Materials process examples representative of the most severe requirements for the facility in terms of electrical power, radio frequency equipment, and the use of an auxiliary electron beam heater were used to discuss matters having the greatest effect upon the space shuttle pallet payload interfaces and envelopes. Improved weight, volume, and efficiency estimates for the RF generating equipment were derived. Results are particularly significant because of the reduced requirements for heat rejection from electrical equipment, one of the principal envelope problems for shuttle pallet payloads. It is shown that although experiments on containerless melting of high temperature refractory materials make it desirable to consider the highest peak powers which can be made available on the pallet, total energy requirements are kept relatively low by the very fast processing times typical of containerless experiments and allows consideration of heat rejection capabilities lower than peak power demand if energy storage in system heat capacitances is considered. Batteries are considered to avoid a requirement for fuel cells capable of furnishing this brief peak power demand

    Performance analysis of 1ϕ T/4 PLLs with secondary control path in current sensorless bridgeless PFCs

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    New power factor correction (PFC) stages such as bridgeless converters and the associated current shaping techniques require grid synchronization to ensure unity Displacement Power Factor (DPF). Sensorless line current rebuilding algorithms also need synchronization with the line voltage to compensate at least for part of the current estimation error. The application of a secondary control path to reach faster and more robustly the proper operation point previously applied in single/three-phase PLLs in grid connected converters is here proposed for the current sensorless bridgeless PFCs. This work analyzes the performance of three single-phase T/4 PLL structures, first without secondary control path, and later with feedforward and feedback secondary control paths, both in simulation and experimentally, and evaluates their applicability to current sensorless digitally controlled single phase bridgeless PFCs based on the current rebuilding technique.This work has been supported by the Spanish Ministry of Economy and Competitiveness under grant TEC2014-52316-R ECOTREND Estimation and Optimal Control for Energy Conversion with Digital Devices
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