Gallium arsenide (GaAs) power conversion concept

A summary design analysis of a GaAs power conversion system for the solar power satellite (SPS) is presented. Eight different satellite configuration options for the solar arrays are compared. Solar cell annealing effects after proton irradiation are considered. Mass estimates for the SPS and the effect of solar cell parameters on SPS array design are discussed

Technology for satellite power conversion

The work is this reporting period was concentrated on electronically calibrating the bolometer detectors. The calibration is necessary for two reasons: first, the power delivered to the rectifying circuit must be known in order to choose a diode with the appropriate barrier height, and second, the power captured by the antenna must be measured if the efficiency of the rectenna is to be divided into antenna efficiency and rectification efficiency. The millimeter wave region operation of the bolometers was simulated with a VHF (10 to 90 MHz) test signal. These detectors are accurate to within roughly 10%. The typical responsivity of the bolometers is 10 volts/watt and the NEP at 20 Hz is 5 times 10 to the minus 9th power W(Hz)-1/2

Technology for satellite power conversion

The work performed in this reporting period has concentrated on the metal-oxide-metal (MOM) diode. The fabrication procedure begins with the deposition of gold probing pads to provide a non-oxidizing contact to test the dc characteristics to the diode accurately. A thin patch capped with an insulating SiO2 layer, is deposited next to form the first half of the diode. The other half of the diode, typically Ni, is deposited completing the conduction path from the oxidized edge of the Ni patch to the opposite gold probing pad. It is important in this step that the last metallization take place without exposing the newly oxidized surface to the atmosphere. Successful production of diodes has been achieved. Work on millimeter wave frequency rectennas incorporating known semiconductor diode technology has been initiated

Technology for satellite power conversion

Components were examined that will be needed for high frequency rectenna devices. The majority of the effort was spent on measuring the directivity and efficiency of the half-wave dipole antenna. It is felt that the antenna and diode should be roughly optimized before they are combined into a rectenna structure. An integrated low pass filter had to be added to the antenna structure in order to facilitate the field pattern measurements. A calculation was also made of the power density of the Earth's radiant energy as seen by satellites in Earth orbit. Finally, the feasibility of using a Metal-Oxide-Metal (MOM) diode for rectification of the received power was assessed

Appropriate methods to analyse power conversion harmonics

Nowadays, non-linear loads represent the majority of the residential electrical consumers. The limits on emission and immunity are imposed by IEC- standards, however there is a lack in the domain 2 – 150 kHz. Where power quality standards focus on the current, EMC standards use voltage limits. An appropriate method for measuring high frequency grid disturbances is explored. Measurement techniques described by the existing standards for power quality and EMC are investigated. The aim of this work is to find a robust measurement method for the considered frequency range 2 - 150 kHz. Experimental results are presented in order to validate the analyzed methods

Hydrogen turbine power conversion system assessment

A three part technical study was conducted whereby parametric technical and economic feasibility data were developed on several power conversion systems suitable for the generation of central station electric power through the combustion of hydrogen and the use of the resulting heat energy in turbogenerator equipment. The study assessed potential applications of hydrogen-fueled power conversion systems and identified the three most promising candidates: (1) Ericsson Cycle, (2) gas turbine, and (3) direct steam injection system for fossil fuel as well as nuclear powerplants. A technical and economic evaluation was performed on the three systems from which the direct injection system (fossil fuel only) was selected for a preliminary conceptual design of an integrated hydrogen-fired power conversion system

Research on spacecraft electrical power conversion

The steady state characteristics and starting behavior of some widely used self-oscillating magnetically coupled square wave inverters were studied and the development of LC-tuned square wave inverters is reported. An analysis on high amplitude voltage spikes which occur in dc-to-square-wave parallel converters shows the importance of various circuit parameters for inverter design and for the suppression of spikes. A computerized simulation of an inductor energy storage dc-to-dc converter with closed loop regulators and of a preregulating current step-up converter are detailed. Work continued on the computer aided design of two-winding energy storage dc-to-dc converters

Research on spacecraft electrical power conversion

The history of spacecraft electrical power conversion in literature, research and practice is reviewed. It is noted that the design techniques, analyses and understanding which were developed make today's contribution to power computers and communication installations. New applications which require more power, improved dynamic response, greater reliability, and lower cost are outlined. The switching mode approach in electronic power conditioning is discussed. Technical aspects of the research are summarized

Electronic amplifier with power supply switching Patent

Increasing power conversion efficiency of electronic amplifiers by power supply switchin

Two-fluid magnetohydrodynamic system and method for thermal-electric power conversion Patent

Thermoelectric power conversion by liquid metal flowing through magnetic fiel