Showing papers on "Photovoltaic system published in 1971"
Patent•
26 Jul 1971
TL;DR: In this paper, a satellite system is used to collect and convert solar radiation to microwave energy by means maintained in outer space on a satellite, which is then transmitted to earth and converted to electrical power for distribution.
Abstract: Solar radiation is collected and converted to microwave energy by means maintained in outer space on a satellite system. The microwave energy is then transmitted to earth and converted to electrical power for distribution.
125 citations
TL;DR: The effects of shadows on the current-voltage characteristics of solar cell circuits are studied and used for the development of several mathematical models, useful in analyses performed by hand or digital computer, using theoretical or empirical input data.
Abstract: The effects of shadows on the current-voltage characteristics of solar cell circuits are studied and used for the development of several mathematical models. These models describe circuits of any geometry with or without shunt or blocking diodes. For efficient analyses of larger arrays the concept of the shadowing factor is developed. All models are useful in analyses performed by hand or digital computer, using theoretical or empirical input data.
106 citations
01 Feb 1971
TL;DR: In this article, the authors discuss the design of solar arrays, including radiation effects on solar cells, substrates, selection of array voltage, analysis of shadows, and overall performance.
Abstract: Photovoltaic solar arrays are the principal means of converting solar energy to electrical energy for satellites. Array configurations depend on the spacecraft stabilization concept, orbit, and power requirements. The current generation of communication satellites are spin-stabilized in synchronous equatorial orbits; their arrays are spinning cylinders. As satellite power requirements increase, it is expected that the trend will be toward extendible arrays on three-axis stabilized spacecraft. The single crystal silicon cell is the basic building block of today's solar arrays and is expected to be for some time, although cadmium sulfide thin film solar cells may offer several advantages once their development is completed. Several of the considerations in the design of solar arrays are discussed: radiation effects on solar cells, substrates, selection of array voltage, analysis of shadows, and overall performance.
9 citations
TL;DR: In this article, a response factor method for generalizing dynamic performance of low-temperature solar energy utilization devices, on the basis of a representative set of experimental test data, is presented.
9 citations
TL;DR: In this article, a high speed solar water heater based on a novel principle is described, illustrated and test results are given, based on which a high-speed solar water water heater is used.
8 citations
TL;DR: The solar array power system placed into a sunsynchronous orbit on the SERT II (Space Electric Rocket Test) Spacecraft was capable of providing over 6 X 10 whr of electrical energy over a period of 6 months as mentioned in this paper.
Abstract: The solar array power system placed into a sun-synchronous orbit on the SERT II (Space Electric Rocket Test) Spacecraft was capable of providing over 6 X 10 w-hr of electrical energy over a period of 6 months. The 56-v, 1100-w sectionoutput is provided directly to a powerconditioning unit with no batteries in the system. The 28-v, 180-w section provided the power to the spacecraft for housekeeping and auxiliary experiments. The deployment technique, which uses springs in each leaf joint to extend the folded array into a flat fixed position, and redundant electrical pyrotechnic circuits to enhance probability of deployment, is discussed.
5 citations
4 citations
01 Jul 1971
TL;DR: Digital regulated solar array module and performance characteristics of its electronic circuits were discussed in this article, where the performance of the electronic circuits of the solar array was compared with those of the conventional solar arrays.
Abstract: Digital regulated solar array module and performance characteristics of its electronic circuits
3 citations
15 May 1971
2 citations
01 Apr 1971
15 Mar 1971
TL;DR: Preliminary design, fabrication, and test of lightweight solar panel of built-up beryllium structure with 29 sq ft active cell area was reported in this paper, with 29 square feet active cell coverage.
Abstract: Preliminary design, fabrication, and test of lightweight solar panel of built-up beryllium structure with 29 sq ft active cell area
01 Jan 1971
TL;DR: In this article, the authors demonstrate the feasibility of direct conversion of solar energy to heat to provide a lightweight, inexpensive power source for orbital cryo cooling, which is also much less expensive than nuclear sources of heat.
Abstract: : The goal of this study is to demonstrate the feasibility of direct conversion of solar energy to heat to provide a lightweight, inexpensive power source for orbital cryo cooling. This was accomplished by: design of a solar heat source for satellite use, optimizing the design for 1250 degrees F, and verifying the design with tests of a scale model. The design and optimization were done by conducting a series of tradeoff studies on the various components. The resulting design is predicted to have an efficiency in excess of 50 percent, at a cost and weight far less than that of competing solar cell powered heaters. It is also much less expensive than nuclear sources of heat. The design provides for sun tracking in any orbit with heat storage provisions for shadow transit. The design includes: a paraboloidal collector, a spherical receiver with a selective solar energy absorbing coating, potassium or sodium-filled molybdenum heat pipe, lithium hydride as the heat storage material, and sun-pointing handled with straightforward state-of-the-art techniques. The verification of system feasibility was by fabrication and testing of a test model. The results of the tests show that the system's operation is predictable. (Author)
Proceedings Article•
01 Jan 1971
TL;DR: In this article, a drive system design for controlling the position and rate of solar power arrays on orbiting spacecraft is presented, in which the signal processing and logic functions are performed by digital and linear integrated circuits.
Abstract: This paper summarizes a drive system design for controlling the position and rate of solar power arrays on orbiting spacecraft. There are no gears or sliding contact elements used anywhere in the system and only low-speed bearings are needed. Such mechanization is particularly well suited to solid lubrication techniques, and wear rates are very low, so that the drive system can operate directly in the space environment for long periods of time. Three major components were developed for implementation of this design concept. They are: 1) a brushless dc torque motor; 2) a rotary power transformer; and 3) an offset-tooth shaft position and rate sensor. These components are combined in a hybrid system configuration in which the signal processing and logic functions are performed by digital and linear integrated circuits. A root contour and describing function analysis, confirmed by experimentation, shows that several modes of limit cycle generation can occur in the vicinity of null. Compensation circuits are given that inhibit or suppress limit cycling and provide controlled electronic damping of the system. The system offers relatively high stiffness and can be operated at indefinitely low angular rates with minimum power consumption.
01 Nov 1971
TL;DR: In this article, the use of solar electric propulsion to raise a high-power communication satellite from a low altitude, inclined circular orbit of the geosynchronous orbit was evaluated, and the performance of the solar electric stage in combination with the thrust augmented Thor/Delta launch vehicle was evaluated for two thrust steering programs.
Abstract: The use of solar electric propulsion to raise a high-power communication satellite from a low altitude, inclined circular orbit of the geosynchronous orbit is evaluated. Since the satellite ascends through the high intensity radiation belts, the power available from the solar array and therefore to the ion thrusters degrades. The performance of the solar electric stage in combination with the thrust augmented Thor/Delta launch vehicle is evaluated for two thrust steering programs. The transfer times and solar array requirements are presented for total geosynchronous payloads from 450 to 1100 kg.
01 Jan 1971
TL;DR: In this article, the authors discuss the con- siderations in the design of solar arrays, including radiation effects on solar wlls, substrates, selection of array voltage, analysis of shadows, and overall performance.
Abstract: Photovoltaic solar arrays are the.principal means of converting solar energy to electrical energy for satellites. Array con- figurations depend on thespacecraft stabilization concept, orbit, and power requirements. The current generation of communication satel- lites are spin-stabilized in synchronous equatorial orbits: their arrays are spinning cylinders. As satdlite power requirements increase, it is expected that the trend will be toward extendible arrays on three- axis stabitizd spacecraft. The single crystel silicon cell is the basic building block of today's sdar arrays and is expected to be for some time. although cadmium sulfide thin-film solar cells may offer several advantages once their development is completed.-Several of the con- siderations in the design of solar arrays are discuss8d: radiation effects on solar wlls, substrates. selection of array voltage, analysis of shadows, and overall performance.
01 Jan 1971
TL;DR: The SEP system as discussed by the authors consists of a solar array, a power point detector, a thruster, an auxiliary power generator, and a switchboard with an auxiliary voltage controller.
Abstract: CONTENTSI. IntroductionII. Basic Characteristics of the SEP System III. SEP Element Development Status A. Solar Array B. Maximum Power Point Detector C. Thruster D. Power Conditioner E. Auxiliary Power F. Switching Matrix G. Propellant Storage H. Thrust Vector Control-Mechanism I. Thrust Vector Control-Electronics J. Controller IV. SEP System - Spacecraft Interactions V. System Mass Summary VI. Conclusions References TABLES1. TVC requirements 2. SEPST III weight summary FIGURES1. Propulsion system block diagram 2. General Electric roll-out solar array 3. Solar array current vs voltage characteristic(typical) JPL Technical Memorandum 33-510112244
16 May 1971
TL;DR: The proposed concept would place in synchronous orbit a very large solar cell array and transmit the electrical energy thus captured to the earth by means of a microwave power transmission system, and would not use any of the earth's fossil or nuclear fuel reserves.
Abstract: Applications: Space Power Station, Recently, Dr. Peter Glaser of A. D. Little, Inc., has proposed that we solve some of the pollution and natural-resource depletion problems associated with present methods of generating electrical energy by tapping otherwise unused solar energy. He would place in synchronous orbit a very large solar cell array and transmit the electrical energy thus captured to the earth by means of a microwave power transmission system. In view of the fact that his concept would indeed be near pollution-free, would not use any of the earth's fossil or nuclear fuel reserves, and could make practical use of our acquired space technology, it is receiving favorable attention.