Showing papers on "Electricity generation published in 1975"

Power stabilizer design using root locus methods

Abstract: This paper describes a different approach to the design of power stabilizers for damping out tie-line power oscillations in power systems. The technique described in this paper was successfully applied at a generating station of the Saskatchewan Power Corporation System with the results from these tests included in the latter part of this paper. The technique can be applied directly to systems characterized by lightly damped oscillations and gives an explicit indication of the amount of improvement in system damping for different combinations of power stabilizer parameters. This procedure allows for a graphical approach to the design of power stabilizers and serves as a synthesis procedure when the design constraints are relaxed so that the speed stabilizer is required to provide an improvement in system damping.

Fluid current turbine with flexible collectors

Abstract: A fluid-current energy-conversion plant, especially useful for electricity generation, utilizing an axial flow turbine as the energy conversion element, has self-inflated flexible collector elements for capturing a portion of the fluid current, increasing its velocity, guiding at least some of each portion into the turbine's mouth, then returning the captured flow into the stream.

The combined costs method for optimal economic planning of an electrical power system

Abstract: A mathematical programming model is described for the economic planning of generation and transmission systems. By iterating between the simulation of operating conditions and the combined costs model the number of constraints are reduced by up to one hundredth of those required for early linear programming models.

The Technological Requirements for Power by Fusion

Abstract: In this paper the major technological requirements for fusion power, as implied by current conceptual designs of fusion power plants, are elucidated and assessed. As the point of departure the four...

Apparatus and method of generating electricity from wind energy

Abstract: The invention relates to apparatus for and method of generating electricity from wind energy. The apparatus comprises means such as a foraminous condenser plate and a condenser surface, e.g., the earth, for producing an electrostatic field in the open through which wind can blow, means such as needle points and balls or fine wires and cylinders capable of creating a corona discharge or equivalent ion or electron generator for producing charged particles to be entrained in and carried by the wind against the direction of movement imposed on the particles by the field, which results in an increase in the electric potential across the field, means such as a second foraminous plate or the earth for collecting the charged particles and means such as a high voltage power regulator and converter for making the increased potential available for utilization. The method comprises operations corresponding to the means, viz., producing an electrostatic field in the open through which wind can blow, generating charged particles to be entrained in and carried by the wind against the direction of movement imposed on the particles by the field, resulting in an increase of the charged particles and making the increased potential available for utilization.

Electrical power generation and storage system

Abstract: A process is disclosed for generating and temporarily storing generated electrical power in electro-chemical, chemical and electro-mechanical mediums and for efficiently reconverting the stored energy back to usable AC electrical energy. In one embodiment of the process, alternating current is converted to direct current which is used to power a chlorine-sodium hydroxide electrolysis cell. Process steam, from a steam generating source, and fuel gas are combined in a reformer process to produce hydrogen and carbon monoxide. The carbon monoxide is then recycled with process steam to form additional hydrogen and carbon dioxide. In addition, the process steam is used to liquify air to form oxygen. The chlorine, hydrogen, carbon dioxide and oxygen gases produced by the processes, are compressed and/or stored in appropriate tanks. The sodium hydroxide is processed, stored and then fed to hydrogen-oxygen fuel cells. The stored hydrogen and oxygen are fed to the hydrogen-oxygen fuel cells, thereby generating direct current which is then inverted to form alternating current. The alternating current is fed into the alternating current power grid for distribution to power consumers. The chlorine is used as a fuel oxidant or may be utilized in water processes. The carbon dioxide is used in refrigerant and other processes.

Electrical power-generation apparatus with rotary voltage transformer and integrated inertial energy storage

Abstract: Generating stations which each have a rotary voltage step-up mechanism integrated with an inertial energy storage device are connected in series through a transmission line to produce high-voltage utility electrical power from distributed primary energy sources, such as arrays of solar energy panels, wind-driven generators or the like, which may be intermittent. Each station in the series may include an elevated generator supported on insulative structure and operating at the high-voltage level of the transmission line to add an increment of voltage and power to the line. The generator is driven through an insulative drive shaft by a motor operated from the nearby primary energy sources. Each station further includes a massive flywheel secured to the drive shaft assembly that links the generator and motor in order to store locally developed energy during periods of excess supply whereby energy may be continued to be delivered to the transmission line during periods of diminished supply or to meet demand peaks.

Integrated Power/Attitude Control System (IPACS)

Abstract: An integrated power and attitude control system (IPACS) for spacecraft is described. The system utilizes energy wheels for electrical energy storage as well as attitude control. Results from the feasibility studies of this concept are summarized and indicate potential weight and cost savings up to 30% over conventional power and control systems. The IP ACS advantage is particularly significant for the longer duration missions which have a large number of energy charge-discharge cycles and higher power requirements. A system for a shuttle-launched Research and Applications Module (RAM) free-flying observatory spacecraft is described. The system utilizes three gimbaled, control, and energy-momentum gyros in a planar array. Each gyro unit is rated at 2.4 kw and delivers 1095 w-hr of energy while maintaining control angular momentum above 1115 N-m-sec. Dynamic response of combined power and control functions was evaluated by digital simulations which included significant nonlinearities and a symmetrical energy distribution law. Simulation data indicate that spacecraft attitude control response is similar to that achieved without the superposition of energy wheel speed changes and is essentially uncoupled from that of the faster power control loop. Both power and control dynamics are well regulated. A NUMBER of spacecraft designs have been develxmoped for the missions of the shuttle era. Most of these require subsystems with lifetimes of 5-7 yr to meet cost effectiveness goals. Pointing requirements below 0.25° are common, with specific scientific missions requiring experiment pointing to 1 arc sec. Momentum storage devices normally are used to provide control torques for long-life missions where control thruster propellant weights and valve life test costs prove excessive. The choice of momentum storage is reinforced, or even required, in several missions where mass expulsion contaminants are prohibited by experiment viewing requirements or where fine pointing stability and slewing is required. The significant impact of the long-life requirement on the electrical power system design is in the sizing of components rather than in the type of system selected. This is because nearly all systems postulated utilize solar arrays for electrical power generation and secondary batteries for electrochemical energy storage. The batteries prove to be the heaviest components of advanced spacecraft solar power systems. The weight of the batteries is determined by the rated energy densities and their inherent characteristic of decreasing life with increased depth-of-discharge and charge-discharge rate. Thus, for a specific energy storage requirement, the designer's major option for increasing battery life is that of increasing the size or number of battery cells thereby decreasing the depth of discharge. As a result, batteries and their controllers commonly constitute 30-40% of an electrical power system weight. Developments of recent years1'2 have shown that flywheels designed to store energy can provide higher energy densities than can be expected from several conventional spacecraft electrochemical devices. In spacecraft applications, parity in energy density between the energy wheel and battery subsystems may result in significant advantage to the energy wheel system. This is because many spacecraft designs currently employ flywheels in momentum storage attitude control systems which approximate the weight of energy wheels.

System performance characteristics of superconducting alternators for electric utility power generation

Abstract: The application of superconductors in the field windings of large steam-turbine generators appears to offer a number of significant economic and operational advantages. The principal advantage offered by such machines appears to be a potentially large reduction in size, weight, and cost for a given power rating. In addition, superconducting alternators also appear to have a number of unique and potentially advantageous operational characteristics, most of which are a consequence of the relatively low per-unit synchronous reactance that is characteristic of these machines. This paper reviews the reasons for the low synchronous reactance attributable to the use of superconducting field winding, and compares the expected performance characteristics of a superconducting alternator in the 1000 MVA range with those of a conventional power system generator of comparable rating. Among the specific topics discussed are performance with regard to dynamic stability, transient stability, voltage regulation, and excitation control. The principal operational advantages of a superconducting alternator appear to be 1) the absence of a dynamic stability limit within its MVA capability, 2) significantly greater transient stability when operating at leading power factors, 3) superior voltage regulation, and 4) no degradation of dynamic stability due to automatic voltage regulator action. Consequently, superconducting alternators appear to be ideally matched to modern power system applications that require operation of generators at leading power factors.

Solar Power via Satellite

Abstract: The possibilities for using satellite solar power stations for large-scale power generation on earth, converting solar energy into microwave energy, transmitting it to the earth’s surface, and transforming it into electricity have recently been explored. The current state of technology and the necessary developments for accomplishing the four functions, i.e., collection of solar energy, conversion to and transmission of microwaves and rectification to DC on the ground, are reviewed. The requirements for flight control, earth-to-orbit transportation, and orbital assembly are discussed. Environmental issues, including impact of waste heat release, water injection into the upper atmosphere by space vehicle exhaust, noise pollution, and location of antenna sites are listed. Biological effects and radio frequency interference are explored. The time frame for accomplishing the operational system is outlined.

Method of operating a nuclear reactor

Abstract: A method of controlling a nuclear power generating station in the event of a malfunction of particular operating components which minimizes the number of hypothecated occurrences where tripping the reactor might become necessary. Upon identification of such a malfunction, preselected groups of control rods are fully inserted sequentially until a predetermined power level is approached. Additional control rods are then selectively inserted to quickly bring the reactor to a second given power level chosen to be compatible with safe operation of the system with the malfunctioning component. At the same time as the thermal power output of the reactor is being reduced, the turbine is operated at a rate consistent with the output of the reactor. Thus, in the event of a malfunction, the nuclear power generating system is operated in a turbine following reactor mode, with the reactor power rapidly reduced, in a controlled manner, to a safe level compatible with the type of malfunction experienced.

Characteristics and maneuverability of CANDU nuclear power stations operated for base-load and load-following generation

Abstract: The characteristics and maneuverability of pressurized heavy water nuclear power units operated for base-load and load-following generation are discussed with respect to the requirements of Ontario Hydro. The nuclear generating units of Pickering G.S. 'A' (Units 1-4) and Pickering G.S. 'B' (being designed for Units 5-8), and the turbine-generator-grid of Bruce G .S. 'A' (Units 1-4) were simulated on digital computers. Simulation tests such as normal loading and unloading at various rates, grid frequency upset, and grid islanded cases were conducted with the unit load regulated by three alternative unit power control systems. The results of the simulation show that the necessary flexibility in power maneuvers to meet the load-following requirements in the Ontario Hydro system may be obtained with the CANDU-PHW (Canadian Deuterium Uranium - Pressurized Heavy Water) generating units controlled by an integrated unit load control system which normally operates in a reactor-following-turbine unit control mode. The simulation results also show that the reactor-following-turbine unit control improves the control of many process systems and the overall plant performance.

Generation Schemes for Wind Power Plants

Abstract: This paper reviews various electric generation schemes for wind energy conversion suitable for interconnection with a power grid. The schemes can be generally classified as constant speed constant frequency (CSCF) and variable speed constant frequency (VSCF) systems. Historically, only CSCF systems have been used for large power generation in wind power plants. However, with the advent of power electronics and the availability of solid state devices capable of handling large amounts of power, VSCF systems are becoming competitive. Various schemes under each classification are discussed and compared. It is stressed, however, that the optimum choice of the generating scheme is not decided by considering the generator alone. The optimum choice is one which minimizes the cost of energy generated by the wind power plant.

Efficient thermo-mechanical generation of electricity from the heat of radioisotopes

Abstract: The thermomechanical generator uses a thermomechanical oscillator to convert heat efficiently into a mechanical oscillation which in turn excites a suitable transducer to generate alternating electricity The thermomechanical oscillator used is based on the Stirling cycle, but avoids the need for rotary motion and for sliding pistons by having a mechanically-resonant, spring- suspended displacer, and by using an oscillating metal diaphragm to provide the mechanical output The diaphragm drives an alternator consisting of a spring- suspended permanent magnet oscillating between fixed pole pieces which carry the electrical power output windings Because a thermomechanical generator is much more efficient than a thermo-electric generator at comparable temperatures, it is particularly suitable for use with a radioisotope heat source The amounts of radioisotope and of shielding required are both greatly reduced A machine heated by radioisotopes and delivering 107W ac at 80Hz began operating in October, 1974 Operating experience with this machine is reported, and these results, together with those obtained with higher-powered machines heated by other means, are used to calculate characteristics and performance of thermo- mechanical radioisotope generators capable of using heat sources such as the waste-management $sup 90$Sr radioisotope sources becoming available from the US nuclear waste management programme Amore » design to use one of these heat sources in a 52-W underwater generator is described (auth)« less

Power from tides— the rance tidal power station

Abstract: This paper discusses the Rance Tidal Power Station, the world's first, which has been operating at full capacity since 1968 and appears to be a very successful achievement. The following areas are covered: 1) Tidal Power Generation including basic engineering and economic requirements, economic optimization, the different possible cycles available, and site selection; 2) Design and Construction Problems including general layout, component structures, cofferdams, and bulb units; 3) Cost and Benefits including reasons for construction decision, running costs, efficiency, indirect benefits, and environmental effects; and 4) Operation Experience including energy generation, efficiency and dependability, and corrosion problems.

Gas and steam turbine contg. power station - includes plant for eliminating sulphur cpds in flue gases

Abstract: The fuels used in the power station such as coal and oil are gasified before the fuel is used for combustion in the turbines etc The gas is obtained from dried and finely powdered coal on using oxygen or oxygen rich gas and steam under a high pressure This gas is cooled subsequently in a waste heat boiler and the steam from this boiler is used in a steam turbine for generating electricity The gas is subsequently cooled further down by injection of water and cleaned in the contact plant so that sulphur bearing gas components are scrubbed out This desulphurised gas is burnt with preheated air and the combustion gases are used in another boiler whose steam is once again used in steam turbine for generating electricity The flue gases are passed through a gas turbine which operates a power generator and an air compressor Exhaust gases from the gas turbine are used for drying of coal

Method and apparatus for generating electricity magneto hydrodynamically

Abstract: Closed cycle energy conversion system in which a magnetohydrodynamic generator operates on high temperature and high pressure water obtained by combustion of hydrogen in oxygen which is obtained by thermal decomposition of water to produce electricity.

Power generation from ocean currents

Abstract: There is considerable energy available from ocean currents. The velocity of these is generally low and it varies with location, the seasons, and with depth from the ocean surface. It is possible to use this energy for power generation and an analysis is presented reviewing various types of water turbines, including Water Wheels, Kaplan Turbines, Propeller Turbines and Vertical Axis Machines. The analysis evaluates the effects of velocity gradients and the machines best suited for this application. Due to the low energy flux, the machinery will get relatively large and is of slow speed. However, since substantial amounts of energy are available, such water turbines may become of interest in specific locations where such units can be built close to the source of energy demand.

Nuclear Versus Fossil Power Plants: Evolution of Economic Evaluation Techniques

Abstract: (1975). Nuclear Versus Fossil Power Plants: Evolution of Economic Evaluation Techniques. The Engineering Economist: Vol. 21, No. 1, pp. 21-38.

Solar sea power plants—electric power from the ocean thermal difference

Abstract: This paper reviews past and current efforts to generate electric power using the natural temperature difference in the ocean waters at different depths. The scheme has been named Solar Sea Power Plants, SSPP for short. SSPP's are essentially pollution-free and can potentially meet an appreciable portion of the electric power demand of the United States mainland, the islands of Hawaii, Puerto Rico, the Virgin Islands and other countries around the globe. An analysis of the cost of SSPP's is presented and it is shown that SSPP's can compete economically with conventional fossil or nuclear-fuel power plants. Finally, problems of system design are discussed with particular emphasis on layout, structures, and various naval engineering problems.

Open-cycle MHD power generation: status and engineering development approach

Abstract: The Electric Power Research Institute (EPRI) has been working with the Fossil Energy Office of the Energy Research and Development Administration (ERDA-Fossil Energy) for the past year on long-range planning for MHD power generation. The current work, issues, and problem areas, some significant criteria, and the overall aspects of the EPRI-ERDA planning activities are reviewed. (WHK)

Method for removing arsenic from hot ground water

Abstract: PURPOSE: A method to remove arsenic in hot ground water as a by-product in geothermal electric power generation by reacting it with iron or its oxide. COPYRIGHT: (C)1977,JPO&Japio

An approach for preventing system insecurities arising from line and transformer outages

Abstract: This paper presents an algorithm that improves steady state security of a power system. An objective function which includes power flows in the overloaded system elements and bus voltages that exceed the permissible limits is formulated. Weighting factors, obtained from the magnitudes and frequencies of the violations, are also used in this function. An optimal combination of controlling variables, such as voltage magnitudes at generator buses, real power generation, transformer and phase shifter tap settings, is determined by minimizing the objective function. Instead of the non-linear load flow equations, sensitivity analysis approach has been used to reduce computation time and effort. This technique has been applied to a 6 bus model and a 26 bus version of the Saskatchewan Power Corporation transmission system; and some of the more interesting results are presented.

Geothermal energy development

Abstract: The Nation has embarked on an aggressive program to develop its indigenous resources of geothermal energy. For more than a decade, geothermal energy has been heralded as one of the more promising forms of energy alternate to oil and gas for electric power generation, but during the last fifteen years, the total capacity in the U.S. has reached 502 MWe, about half the size of a single modern nuclear power plant. And yet, the United States, especially its western and Gulf coast states, is believed to possess a vast resource base of geothermal heat at depths up to 3 to 10 km. Many estimates of these potential resources suitable for the production of electric power have been published and they range over a spectrum of more than a factor of 100. This variation suggests that the potential is essentially unknown. Table 1 gives a range of published forecasts for the year 1985 and the equivalent potential in number of 1000 Mwe power plants and in oil consumption in millions of barrels per day. In view of the estimated construction of about 200 to 250 nuclear power reactors by 1985-90, the pessimistic forecasts clearly show that the contribution of geothermal energy to the Nation's energy supply may indeed be small. The optimistic forecasts represent more than 15% of the total electric power requirements estimated for the year 1985. The Task Force for Geothermal Energy, in the Federal Energy Administration Project Independence Blueprint report of November 1974, established a national goal for 1985 of 20,000 to 30,000 MWe, the latter value representing an equivalent energy supply of one million barrels of oil per day. This goal was clearly a compromise between what is worth a national effort and what might be realistically achieved. The potential for adding or replacing the equivalent of some 25 nuclear power plants or for conserving one million barrels of oil per day should be an adequate incentive for the Nation to accelerate the development of a viable geothermal industry.