Showing papers on "Electric power published in 1992"

Electric power monthly

Abstract: The Electric Power Monthly is prepared by the Survey Management Division; Office of Coal, Nuclear, Electric and Alternate Fuels, Energy Information Administration (EIA), Department of Energy. This publication provides monthly statistics at the national, Census division, and State levels for net generation, fuel consumption, fuel stocks, quantity and quality of fuel, cost of fuel, electricity sales, revenue, and average revenue per kilowatthour of electricity sold. Data on net generation, fuel consumption, fuel stocks, quantity and cost of fuel are also displayed for the North American Electric Reliability Council (NERC) regions. Additionally, statistics by company and plant are published in the EPM on capability of new plants, new generation, fuel consumption, fuel stocks, quantity and quality of fuel, and cost of fuel.

Battery powered electric vehicle and electrical supply system

Abstract: A charging system for a battery powered electric vehicle has means (2, 3, 4, 6, 13, 7) for passing electric power to or from its battery in either direction, to or from a utility/mains (100), whereby load-levelling on the mains can be effected. Control of the procedure can be effected by the utility through a suitable communications link. A traction drive system for an electrically driven vehicle having this type of charging system includes an AC traction motor (5) and a pulse width modulated converter (2) controllable to convert a DC electrical signal from a battery (1) into an AC drive signal for the motor (5). A switch means (4) is connected to a port of the converter, for switching the second port between the traction motor and an AC input port, so that the mains supply can be used to charge the battery (1).

High quality electrical power distribution system

Abstract: The system comprises a central module supplying a distribution network, for example formed by a bus, with permanent DC power. Terminal modules, located near the loads, convert the DC power distributed by the distribution network into DC or AC electrical power adapted to the requirements of each load. A communication bus enables data communication between the various modules.

Non-contact data and power connector for computer based modules

Abstract: The invention discloses a non-contact way to provide electrical power and two-way digital communications between a host computer and its peripheral modules, such as IC memory cards, modems, and A/D converters. A special magnetic core is employed to provide efficient transfer of both large amounts of electrical power and high speed digital communications through transformer action. Peripheral modules requiring different power supply voltages or different data voltage levels can be accommodated and intermixed with modules of other types in the same host system. The mechanical design of the connector includes detent structure to align the assembly in three dimensions, both upon mating, and under mechanical environmental stress conditions during operation. The magnetic core has both power supply and data windings; the data winding has sections of opposite polarity so that the power supply signal imposed on the data winding cancels itself.

Drive arrangement for a motor vehicle

Abstract: The drive arrangement for a motor vehicle comprises an internal combustion engine (1) with at least one controlling element (29) affecting its power and/or torque and/or rotation speed, controllable by a motor element (27), an electric generator arrangement (3) driven by the engine (1), at least one electric motor (11) powered by the generator arrangement (3) and driving the motor vehicle and an electronic control (19) which controls at least the one motor element (27) and the electric power supplied by the generator arrangement (3) and/or the electric power taken by the electric motor (11) depending on the position of an accelerator pedal (23). The arrangement includes means for detecting the actual value of the rotation speed of the engine (1) and means for detecting an actual value of the power supplied by the generator (3). The control (19) comprises rotation speed regulators (33), which maintain the actual rotation speed at a predetermined setting, and power regulators (37) which maintain the actual electric power at a predetermined setting. To the control (19) is allocated a data store (31) in which characteristic data for combinations of data for the power setting and data for the rotation speed setting and/or data for regulating the at least one motor element (27) are stored. The control (19) selects the data combinaison depending on the position of the driving pedal (23). The data combinaisons determine operating points of the motor characteristic for optimum settings of at least one driving parameter, e.g. minimum fuel consumption and/or minimum pollutant emission and/or minimum noise. The characteristics of the driving parameters can be updated on the basis of constant power from the engine (1) or the generator (3).

Electric power system

Abstract: An electric power system has an air compressor unit with a reservoir tank, an air powered motor and an electric generator. The air compressor unit has an air compressor that provides compressed air to the reservoir tank. The air compressor is driven by an electric motor. The air powered motor is driven by compressed air from the reservoir tank. The air powered motor provides rotary power to an input shaft of the electric generator, wherein the generator produces electrical power. The system can be mounted onto a mobile platform for ease of transport. Also, storage batteries can be connected to the electric output of the generator. The output of the batteries can be connected to the electric motor of the air compressor unit.

Motor vehicle drive system for a motor vehicle having an electric motor system, and a method of operating said drive system

Abstract: The motor vehicle drive system is for a motor vehicle having an electric motor system, an actuating system, an accelerator system, a mode selector and a battery. The drive system comprises a power supply bus having an output for supplying the electric motor system; a battery connector for connection to the battery, the connector having a power output for supplying the power supply bus; a controller system having inputs respectively for connection to the components of the vehicle so that it can monitor their status; a power converter system connected to the power supply bus of the controller system, and to the motor system for supplying it; a combustion motor electric power supply having an input connected to the controller system, and an output for producing current; a first power converter having an input connected to the power supply, and an output for supplying the power supply bus, the controller system being connected to the power converter so that it is monitored and controlled by the controller system, whereby the controller system monitors and controls operation of the electric motor system and, when auxiliary electric power is needed on the power supply bus, the controller system activates operation of the combustion power supply.

Hybrid fuel battery system and the operation method thereof

Abstract: A hybrid fuel cell system including a fuel cell for generating electric power by reacting fuel gas and oxidant gas, current restricting structure for restricting an output current of the fuel cell, a storage cell connected parallel to a series circuit comprising the fuel cell and the current restricting structure for helping the fuel cell to supply electric power to an external load, external load fluctuation detecting structure for detecting a fluctuation in the current demanded by the external load and current limitation adjusting structure for following the fluctuation in the current demanded by the external load by changing the restriction of the output current of the fuel cell which is made by the current restricting structure, with the passage of time.

Characteristics of low frequency electric and magnetic fields in the vicinity of electric power lines

Abstract: The authors describe the quasi-static and radiation fields of simple three-dimensional sources and proceed to a two-dimensional source. It is shown that the quasi-static approximations result in an error of 0.000002% for fields at 100 m or less from the power line. This is followed by a discussion of how the quasi-static fields are coupled together by Maxwell's equations. It is shown that the electric field of a power line can formally be determined from the magnetic fields, but this cannot be done practically. The electric and magnetic fields are assumed to be independent and are related respectively to voltage and current. The conditions under which electric and magnetic fields are related by the free space impedance are discussed. In general, they are not for power line fields. Poynting's theorem is applied to the power line fields to describe the bulk power transferred along the power line as a result of the quasi-static fields and to calculate the insignificant amount of power radiated laterally away from the power line. >

An overview of the solar power satellite option

Abstract: The objective of the solar power satellite (SPS) is to convert solar energy in space for use on earth. Its most significant benefit is the potential for continuously generating large-scale electric power for distribution on a global basis. The SPS system is outlined, and the status of the SPS concept development is reviewed. Assessments of key issues are reported including economic considerations and environmental issues as well as physical resource requirements. Legal issues and the need for international agreements on SPS operations are outlined. International SPS-related activities within the context of evolving space programs are discussed. An approach for an evolutionary advancement of SPS to meet requirements for power supplied for use on earth and in space is presented, and a growth path to achieving the potential of power from space for use on earth is outlined. The significance of advancements in technologies applicable to the development of the SPS are discussed. >

Low impedance bus for power electronics

Abstract: A low impedance, high power bus for conduction of electrical power with reduced transient signal effects is described herein. The high power bus can be applied as a high power supply bus between a constant voltage source and a plurality of switching cells positioning at varying locations along the bus, and as branch bus for the switching cells. The power bus can transmit high power: large currents in the hundreds or thousands of amperes, and large voltage potentials in the hundreds or thousands of volts. Particularly, the power bus has use in a DC-to-AC inverter that converts DC from a constant voltage source into three-phase AC for delivery to an electrical power grid. The high power bus includes two conductive bars positioned so that the current flow therethrough is balanced (equal and opposing), and the magnetic field is substantially confined between the bars. The bus includes a dielectric positioned between the conductive bars. In a preferred embodiment, the AC is conducted on extension bars that extend along the power supply bus, so that a main bus is created by the combination of the AC extension bars and the DC power supply bus, and the sum of the currents in the bars is approximately zero at all locations in the bus. The power bus lessens or even obviates the need for the snubber networks commonly used to reduce transients, and reduces the strength of magnetic fields and electric fields that could otherwise interfere with neighboring electrical components.

Low temperature solar-to-electric power conversion system

Abstract: The apparatus is a low-temperature solar to electric power conversion system. A solar collector directs solar insolation to a cavity receiver which heats primary thermal transport fluid to approximately 700° F. An auxiliary fossil or biomass heater may be used to replace or supplement the solar-powered cavity receiver. The primary thermal transport fluid is provided to a Stirling engine which provides electric power and hot water heated to approximately 160° F.

Autonomous wind energy conversion system with a simple controller for maximum-power transfer

Abstract: The paper describes a small autonomous wind energy conversion system that has been designed and implemented as a prototype unit for the demonstration of wind-electricity generation. A simple, closed-loop control system assures maximum-power transfer by the aid of a lookup table which relates the electrical power output of the system to the shaft speed. The lookup table is deduced from the turbine and generator data and corrected by field tests. A directly-coupled, wound-rotating field synchronous generator is used for energy conversion. The generator speed in this system is variable while the terminal voltage is substantially constant. The terminal voltage is kept under control by varying the field current to meet various load and battery conditions. In the paper a new criterion for determining optimum dimensions of a generator for wind energy conversion system applications is introduced. This criterion envisages a maximisation of the energy output for the chosen wind regime while keeping the generator cost at a minimum. To obtain the optimum solution of the cost minimisation problem, the constrained optimisation problem is first converted to the unconstrained form by using the external penalty approach and then solved using the Devidon-Fletcher-Powel method. Results of the optimisation are presented and evaluated in the paper.

The Cost of Electric Power Interruptions in the Industrial Sector: Estimates Derived from Interruptible Service Programs

Abstract: The electric power industry has become increasingly interested in the value customers place upon service reliability, with the demand for reliability couched in terms of outage or shortage costs. The survey-based method of eliciting these costs dominates the literature. This paper explores and demonstrates a method for estimating outage and shortage costs based upon behavioral data. A discrete choice model is developed for estimating shortage costs using observed decisions of industrial customers regarding participation in interruptible service programs. The resulting shortage cost estimates of $4 per kWh unserved for a one-hour interruption are consistent with previous survey-based estimates.

Circuit breaker switchboard.

Abstract: A switchboard (10) for mounting and supplying electrical power to a plurality of circuit breaker (14). The switchboard comprises a frame (16) including a center mounting pan (46), and at least first and second circuit breaker mounting pans for engaging and supporting the rear end portions of the circuit breakers. The switchboard also comprises a power stack assembly (12) mounted on the center mounting pan of the frame. The power stack assembly includes first, second and third, substantially vertically disposed main bus bar members (52, 54, 56) for being connected to a source of electrical power and for releasably engaging the circuit breakers. The power stack assembly further includes a channel vent cover (30). Further, in the preferred embodiment the center mounting pan and the main bus bars are provided with ventilation openings (50) along their lengths to further facilitate airflow through the power stack assembly.

Wall/ceiling mounted inductive charger

Abstract: A weatherized curb-side battery charging system that provides a mechanism for transferring electrical power to an electric vehicle to recharge its battery. The battery charging system includes a housing that is disposed on a wall or is slidably attached to a track mounted to a ceiling, for example A retractable charging device is coupled to a power supply and mates with a receptacle device disposed in the vehicle. A variety of charging devices that may be employed in the battery charging system are disclosed. Electronic circuitry controls power supplied to the vehicle from the power supply of the charging system. In addition, an interface circuit is provided that allows a user to enter a code to use the system and that provides an identification for billing purposes, or a credit card type key that activates the system and performs the same functions. A fan is provided for cooling purposes that causes an air flow through the system. The curb-side charging system thus permits an operator of an electric vehicle to charge its battery in a convenient manner. The battery charging system allows an electric vehicle to be charged safely without any type of conventional electrical plug. The battery charging system provides a safe, convenient and weatherproof mechanism for coupling power from a power source to an electric vehicle to recharge its battery.

Air conditioning apparatus for an electric vehicle using least power consumption between compressor and electric heater

Abstract: An air conditioning apparatus for heating a cabin of an electric car having reduced electric power consumption is disclosed. An initial setting of the heating operation is that of using a refrigerating cycle 17. An average value of actual electric power consumption using the refrigerating cycle for a predetermined period is calculated. Furthermore, electric power consumption using an electric heater 20 is calculated for obtaining the same heating capacity as that obtained by the refrigerating cycle. A switching of the heating operation from the refrigerating cycle to the electric heater 20 takes place when it is determined that electric power consumption using the electric heater is less than that using the refrigerating cycle 17.

Harmonic filtering for the offshore industry

Abstract: The application of a large number of adjustable speed drives (ASDs) operating electric submersible pumps (ESPs) on two separate offshore platforms, connected to a limited electrical power system on a tanker feeding power to the platforms via subsea power cables, presents technical problems involving high levels of harmonic distortions that experience shows can impact the overall system reliability. Such a system is described and discussed in detail and practical solutions to the problems are illustrated. The design of the harmonic filters are shown to have a major impact on the overall operation of the power system. >

The power of self-esteem

Abstract: Describes the ways that ordinary families fail to develop self-esteem and self-acceptance in children, and suggests techniques for adults to do so on their own.

Disk drive power control circuit and method

Abstract: A disk drive control circuit and method controls electric power consumption in a disk drive so that a computer system such as a laptop computer can conserve power and as a result can dramatically reduce the effective life of batteries employed as a power source of the computer system. The disk drive control circuit and method is effective in reducing a power consumption for very small form factor disk drives. A technique is provided to allow the user to adopt the performance versus power consumption to meet the system requirements. The control circuit and method effectively controls transient currents associated with initiation of mechanical operation such as an actuator for actuating a magnetic head and a spindle motor for rotating a magnetic disk at high speed with optimum starting time. The disk drive control circuit and method includes a micro-controller for controlling a total operational procedure for reducing an electric power consumption programmed by a vendor or instructed by a user in addition to an overall operation of the disk drive. The disk drive control circuit also includes a memory for storing a set of programs for the operation of the disk drive. The memory includes profiles (such as current versus access time table) for the current control. An actuator current control limits the flow of current to the actuator based on instructions from the micro-controller. A spindle motor current control limits the flow of current to the spindle motor based on instructions from the micro-controller.

Adapter unit for adaptively supplying a portable radio telephone with power

Abstract: An adapter unit for adaptively supplying a portable radio unit with electric power is disclosed, When the portable radio unit being not powered by a rechargeable battery attached thereto or being not in a communication state is connected to the adapter unit, the first power supply circuit of the adapter unit supplies the rechargeable battery or the portable radio unit with power. When the portable radio unit being in the communication state is connected to the adapter unit, the second power supply circuit of the adapter unit sup-plies the portable radio unit through the rechargeable battery with power. Power supply capacity of the second power supply circuit is larger than that of the first power supply circuit.

Shunt connected superconducting energy stabilizing system

Abstract: A shunt connected energy stabilizing system with isolation switching for providing stored energy to loads or to a utility or industrial electrical distribution system or source of electrical power. An energy backup and recovery system stores energy in a superconducting magnet and releases the energy to a real power/reactive power (VARs) generator which in turn delivers energy to either the loads or to both the loads and the source of electrical power. During periods of voltage sag or power outage, an isolation switch provide a means for isolating the loads from the source of power so that energy can be supplied to the loads only to provide "ride-thru". In effect, the isolation of the load sheds this load from the power system, thereby boosting the rest of the electrical distribution to a level so that other loads on the power system are not disturbed by the voltage sags. By supplying energy to the loads only, small superconducting magnets can be used thereby providing economic and size advantages. The isolation switch also provides a smooth transition from the real power generation to the VAR compensation mode, and vice versa. Additionally, the isolation switch can direct stored energy to both the electrical system and to the loads at the same time.

Thermostat providing electrical isolation therein between connected heating and cooling transformers

Abstract: A low voltage space thermostat adaptable for controlling a heating-only apparatus or a heating and cooling apparatus. The thermostat includes a DC power supply and a voltage step-up transformer having two primary windings and a secondary winding for supplying electrical power to the DC power supply when there is a demand for heating, cooling, or fan operation. The thermostat also includes circuit means for supplying electrical power to the DC power supply when there is no demand for heating, cooling, or fan operation. The thermostat further includes circuit means, responsive to the existence of electrical power at a particular one of its wiring terminals, for providing electrical isolation, from each other within the thermostat, of two transformers incorporated in a two-transformer heating and cooling apparatus.

Electric vehicle with downhill electro-generating system

Abstract: A vehicle having an electro-generating system which includes a dynamoelectric generator. The shaft of the dynamoelectric generator is linked directly or indirectly with the rotating axle of the road wheels of the vehicle, preferably via a mechanical turns amplifier. The turns amplifier will multiply the rotation rate of the electro-generating system and increase the production capacity of electric power. The dynamoelectric generator can be utilized to recharge a storage battery driving the vehicle while the car is in motion, especially automatically when the vehicle is going down hill. The vehicle's electric motor can be driven directly from a dynamoelectric generator in place of a storage battery after the vehicle is moving. In railroad cars (freight and passenger) the electro-generating system can be utilized to charge storage batteries, with their electricity utilized for other electro-energy requirements.

Battery charging device for electric vehicles

Abstract: A battery charging device for electric vehicles with a high-voltage battery, has a first connector to be connected with a high-voltage power source outside the vehicle, a second connector to be connected with a low-voltage power source outside the vehicle, a DC-DC converter for increasing the voltage of the low-voltage power source to a voltage corresponding to the high-voltage battery and a switch for changing-over the connectors are provided. In an emergency where the residual electric energy of the battery is less than required to run the required distance, the electric vehicle can easily be supplied with electric power from other vehicles such as a gasoline engine vehicle having a low-voltage power source and charge the battery by converting the supplied voltage by way of the DC-DC converter to a voltage corresponding to the voltage of the high-voltage battery.

Power conversion system with dual permanent magnet generator having prime mover start capability

Abstract: A starting/generating system operable in a starting mode and in a generating mode utilizes a dual permanent magnet generator (DPMG) having a motive power shaft and an armature winding together with a power converter having an input and an output. Relays are operable in the starting mode to connect the output of the power converter to the DPMG armature winding and are operable in the generating mode to connect the input of the power converter to the DPMG armature winding. The power converter is controlled in the starting mode such that the DPMG is operated as a motor to produce motive power at the motive power shaft and is controlled in the generating mode such that electrical power developed in the DPMG armature winding is converted into output power.

Solar power-operated construction work warning lamp

Abstract: A solar power-operated, construction work warning lamp comprising a base covered by a bottom cover to hold a power supply control circuit and a column, the power supply control circuit consisted of a storage battery, a power switch and an IC board, the column having a plurality of LEDs thereon respectively connected to the power supply control circuit, a lamp guard mounted on the base at the top and covered with a transparent, convex cover, a solar cell assembly supported on the column inside the lamp guard and electrically connected to the power supply control circuit, and a plurality of reflectors mounted on a plurality of openings around the lamp guard, wherein the radiant energy of sunlight collected by the solar cell assembly is converted into electric power for charging the storage battery and for driving the light emitting elements to flash signals by means of the control of the IC board and the power switch.