5,366 research outputs found
Modeling and Analysis of Power Processing Systems
The feasibility of formulating a methodology for the modeling and analysis of aerospace electrical power processing systems is investigated. It is shown that a digital computer may be used in an interactive mode for the design, modeling, analysis, and comparison of power processing systems
Component modeling handbook
Handbook on nonlinear mathematical models for electronic component
Modeling and analysis of power processing systems: Feasibility investigation and formulation of a methodology
A review is given of future power processing systems planned for the next 20 years, and the state-of-the-art of power processing design modeling and analysis techniques used to optimize power processing systems. A methodology of modeling and analysis of power processing equipment and systems has been formulated to fulfill future tradeoff studies and optimization requirements. Computer techniques were applied to simulate power processor performance and to optimize the design of power processing equipment. A program plan to systematically develop and apply the tools for power processing systems modeling and analysis is presented so that meaningful results can be obtained each year to aid the power processing system engineer and power processing equipment circuit designers in their conceptual and detail design and analysis tasks
Microprocessor controlled novel 4-quadrant DC-DC converter
The thesis describes a novel 4-quadrant DC-DC converter,
supplied by a 28V DC voltage source, with an output voltage
which may be continuously varied between +180V and -180V DC.
A prototype 1.2kW DC-DC converter was designed and built,
with emphasis given to the optimization of both the converter
size and efficiency. This was achieved by means of a
computer-based simulation study, which determined the
optimal switching frequency and the size of the inductors
and capacitors while maintaining a high unit efficiency.
Mos-Gated Bimos switches, which feature the advantages of
both mosfets and bipolar transistors, were developed to
achieve high switching speed during high power operation.
A digital-controlled DC servo system based on a 16-bit
Intel 8086 microprocessor was designed, to provide both
motor speed and position control. Speed and position detection
circuits and the structure and the interfacing arrangement
of the microprocessor system were designed and
constructed. Several control algorithms were developed,
including PID Control Algorithm and Current-Limit Control
Algorithm. Based on open loop transfer function of the system,
derived through mathematical modelling using the State-Space
Averaging Method, the constants for the control
algorithms were obtained to meet the dynamic performance
specified for the system.
Computer simulation was carried out to assist with the
design of the converter and the control system.
It is expected that drives into which the novel converter
is incorporated will find many applications in situations
where accurate positional control is required, particularly
in battery-operated DC-servo system, such
as satellite system,
robots and some military vehicles
Development of reliability methodology for systems engineering. Volume II - Application - Design reliability analysis of a 250 volt-ampere static inverter Final report
Design stage reliability analysis application to static inverte
Nd:YAG development for spaceborne laser ranging system
The results of the development of a unique modelocked laser device to be utilized in future NASA space-based, ultraprecision laser ranger systems are summarized. The engineering breadboard constructed proved the feasibility of the pump-pulsed, actively modelocked, PTM Q-switched Nd:YAG laser concept for the generation of subnanosecond pulses suitable for ultra-precision ranging. The laser breadboard also included a double-pass Nd:YAG amplifier and provision for a Type II KD*P frequency doubler. The specific technical accomplishment was the generation of single 150 psec, 20-mJ pulses at 10 pps at a wavelength of 1.064 micrometers with 25 dB suppression of pre-and post-pulses
ASDTIC control and standardized interface circuits applied to buck, parallel and buck-boost dc to dc power converters
Versatile standardized pulse modulation nondissipatively regulated control signal processing circuits were applied to three most commonly used dc to dc power converter configurations: (1) the series switching buck-regulator, (2) the pulse modulated parallel inverter, and (3) the buck-boost converter. The unique control concept and the commonality of control functions for all switching regulators have resulted in improved static and dynamic performance and control circuit standardization. New power-circuit technology was also applied to enhance reliability and to achieve optimum weight and efficiency
Generadores de pulso del orden de nanosegundos para control de calidad y diagnosis de las cámaras de telescopios Cherenkov
Tesis inédita de la Universidad Complutense de Madrid, Facultad de Ciencias Físicas, Departamento de Física Aplicada III (Electricidad y Electrónica), leída el 30-11-2015Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEunpu
Mathematical modelling of permanent-magnet brushless DC motor drives
Brushless dc motor drives have become increasingly
popular, following recent developments in rare-earth
permanent-magnet materials and the semiconductor devices used
to control the stator input power and to sense the rotor
position. They are now frequently used in applications such
as flight control systems and robot actuators, and for
drives which require high reliability, long life, little
maintenance and a high torque-to-weight ratio. In many motor
drives the presence of torque and speed ripples, especially
at low speed, is extremely undesirable. The mathematical
model developed in this thesis was used to investigate their
occurrence in a typical brushless dc drive system, with the
objective of establishing factors which effect their
magnitude and ways by which they may be reduced. The model
is based on the numerical solution of the differential
equations for the system, with those for the motor being
formulated in the phase reference frame. Tensor methods are
used to account for both the varying topology and the
discontinuous operation of the motor arising from changes in
the conduction pattern of the inverter supply switches.
The thesis describes the design, construction and testing
of an experimental voltage source PWM inverter, using MOSFET
switching devices, to drive a 1.3 kW 3-phase brushless dc
motor. A practical circuit is described which implements
current profiling to minimize torque ripple, and the optimum
phase current waveforms are established. The effect of
changes in the firing angle of the inverter switches on the torque ripple are also examined.
Throughout the thesis, theoretical predictions are
verified by comparison with experimental results
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