Showing papers on "Electric power published in 1983"

Power-conserving control system for turning-off the power and the clocking for data transactions upon certain system inactivity

Abstract: A control system, as for controlling automotive body functions, is powered by a limited capacity electrical power source and is structured and controlled in a manner to minimize consumption of electrical power. The control system conducts data transactions between a central control station and one or more remote controllers connected therewith, and the central control station includes a provision for electronic signal processing for controlling the data transactions with the remote controllers. A power FET is operatively connected to the power source and to a portion of the control system for selectively connecting or disconnecting power to that control system portion. The system employs a NMOS microprocessor. The portion of the control system from which power may be disconnected will typically include the processor. The level of system activity is monitored and a power-down, or "sleep" control signal is automatically provided if a predetermined condition of inactivity occurs. That power-down control signal is operatively applied to certain control circuitry for in turn causing the power switch to disconnect power when the power-down control results. Correspondingly, a timer, which preferably is continuously powered, times a "sleep" interval during which power is disconnected from the relevant control system portion and generates a power-up control signal at the end of some predetermined time. The control circuitry responds to this power-up control signal by causing the power switch to reapply power to the previously disconnected portions of the control system.

From Shafts to Wires: Historical Perspective on Electrification

Abstract: The shift from steam to electric power in manufacturing is recounted. Between 1880 and 1930 the production and distribution of mechanical power rapidly evolved from water and steam prime movers with shaft and belt drive systems to electric motors that drove individual machines. The use of electricity reduced the energy required to drive machinery, but more important, enabled industry to obtain greater output per unit of capital and labor input.Reduced energy needs and increased productivity in manufacturing influenced the relationship between energy consumption and gross national product in the first three decades of the twentieth century.

Compact electrical power supply for signal processing applications

Abstract: The present invention relates to a compact electrical power supply which derives electrical energy from a low frequency medium voltage source (eg a 120 V 60 Hz ac main), and converts the electrical energy to a low voltage format suitable for solid state signal processing equipment The supply entails in succession bridge rectification means, a dc-dc boost converter, a capacitor storage bank, and a half bridge converter, either resonantly or non-resonantly operated The converters operate at frequencies substantially above audible frequencies in the interests of compactness The design provides a high input power factor (inductive) with minimum EMT, and provides a lengthened voltage hold up after loss of power

Regenerator for an intrabundle power-line communication system

Abstract: A regenerator (10) for providing detection, remodulation, and retransmission of a digital data signal (20) propagated in the differential mode over a pair of bundle conductors (12,16) of a power line. The electric power signal, propagated in the common mode over the same bundle conductors, is conducted through the regenerator and provides a power supply voltage (V.) for the regenerator electronics. A series of electrical traps (38, 40, 42, 44) prevent the electric power signal from being conducted into that portion of the regenerator utilized for processing of the data signal. The regenerator also includes bypass switches for bypassing the regenerator electronics when a power supply voltage sufficient to operate the electronics is unavailable.

Carbon particulates cleaning device

Abstract: A carbon particulates cleaning device for collecting carbon particulates in exhaust gases discharged from an internal combustion engine and burning off the collected carbon particulates, is disclosed. The carbon particulates cleaning device comprises a heat resistant filter member, an electric heater which is provided on the upstream end surface of the filter member for regenerating the filter member, and an electric power source for supplying electric current to the electric heater. The electric heater is composed of at least two kinds of heating resistors, each of which applies different electric power to a unit area of the upstream end surface of the filter member. At the filter member regenerating time, electric current is supplied to the heating resistors successively in the order of from one providing the maximum electric power density to one providing the minimum electric power density.

Advanced power cable technology

Abstract: This two volume reference combines the basic concepts of power cable technology with descriptions of actual and future designs and performances of power cables. Cable engineers, students and management personnel who are interested in electric power engineering and underground transmission will find the tables and equations that highlight these volumes helpful. Vol. I, BASIC CONCEPTS and TESTING and: Presents a basic introduction to electric energy and underground transmission. Cable design, structural materials such as conductors, insulating materials and protective coverings, and electrical breakdown characteristics are just some of the aspects covered. In addition, all types of testing methods are thoroughly reviewed. Vol. II, PRESENT and FUTURE: Structures, manufacturing processes, improvement of extruded cables, OF cables, POF cables, forced cooled cables, their splices and terminations, gas insulated cables, DC cables and cables for nuclear power stations are discussed. Cryogenic resistive, superconducting and other new types of cables are studied.

The timing of EV recharging and its effect on utilities

Abstract: Electric vehicles (EV's) represent an important future load on the electric utility system which, if properly managed, could increase power plant utilization and reduce the average cost of generating electricity. A future EV population of 7.5 million is addressed, together with its characteristics, vehicle use, consequent recharging loads, and the impact of EV's on electric utilities in terms of the generation of electric power, fuel use, and costs. The impact on utilities will depend in part on when the vehicles are recharged. If the price of electricity is uniform throughout the day, recharging is likely to begin when vehicles are parked at home. Most of the recharging would then occur during late afternoon and early evening hours when other demands for electricity are high. In the year 2000, peak electricity demand would increase by 5700 MW, and oil- and gas-fired power plants would generate 39 percent of the recharge power. Marginal generating costs would average 7.6 cents/kWh in 1982 dollars. If electricity were priced by time of day, recharging could shift to late night hours when the other demands for electricity are low. The peak demand would increase by only 400 MW; 27 percent of the power would come from oil and gas, and marginal generating costs would average only 5.1 cents/kWh, some 25 percent less than the marginal cost of the system load without EV's. The fuels to recharge EV's were found to vary from one region of the country to the next. Utilities in the northeast would use the most oil and gas for recharging (more than 75 percent), while those in the central part of the country would use the least.

Apparatus for controlling an A-C power elevator

Abstract: An apparatus for controlling an A-C powered elevator in which A-C electric power is converted into D-C electric power through a rectifier, the D-C electric power thus converted is converted into a A-C electric power of a variable frequency via an inverter, an A-C electric motor is driven by the thus converted A-C electric power, the A-C motor being controlled by a controller which is connected to a D-C control source, a cage is driven by the thus controlled electric motor, said motor producing regenerated electric power depending upon the operation condition of said cage, wherein provision is made of a regenerated electric power controlling device which is connected between the D-C side of the inverter and the controller in order to supply the regenerated electric power to the controller. When the voltage on the D-C side of the inverter becomes greater than a predetermined reference value, a switching element is rendered conductive, and the regenerated electric power is supplied to the controller. Therefore, a power regenerating inverter need not be independently provided, and the apparatus can be cheaply constructed. Further, since the electric power is not wastefully consumed, energy can be saved.

Apparatus for converting flow of water into electrical power

Abstract: Apparatus for generating electrical power includes a floatable platform, which supports a plurality of water wheels. The shafts of the water wheels are interconnected in tandem for driving an electric generator. The speed of rotation of each of the water wheels is regulated by adjustably positioning the respective vanes thereof.

Starter control apparatus for automotive vehicles

Abstract: A starter control apparatus for automotive vehicles comprises a key-board arranged to be operated by an operator prior to operation of a key switch for producing an electric code signal indicative of identification of the operator, a collator arranged to memorize a specific code for the vehicle's proprietor and responsive to the electric code signal to produce a concord signal therefrom when the contents of the electric code signal accords with the memorized specific code and to produce a discord signal therefrom when the contents of the electric code signal discords with the memorized specific code, and a power supply control circuit arranged to permit the electric power supply to a starter circuit for a prime mover of the vehicle in response to operation of the key switch when received the concord signal from the collator and to prohibit the electric power supply to the starter circuit when received the discord signal from the collator.

Relating cellular energy generating and storage device

Abstract: A rotating cellular energy generating device for generating electrical power for extended periods of time. The generating device characterized by having an annular rotating housing having a plurality of individual compartments therein. The compartments receiving material which is compartmentalized to accurately control the mass distribution in the rotating housing for maintaining speed as power is withdrawn or generated during the rotation of the housing.

Energy conversion system

Abstract: A system of hardware and controls, know as a Hydrogen Hub, that absorbs electric power from any source, including hydropower, wind, solar, and other energy resources, chemically stores the power in hydrogen-dense anhydrous ammonia, then reshapes the stored energy to the power grid with zero emissions by using anhydrous ammonia to fuel diesel-type, spark-ignited internal combustion, combustion turbine, fuel cell or other electric power generators.

Differential protective relay

Abstract: A differential protective relay for protecting devices on an ac electrical power system. The protected devices can include a transformer, a generator, or a station bus. The differential protective relay evaluates the current flowing into and out of the protected device only during the period when the current transformers are not saturated. The differential protective relay also detects internal faults accompanying external faults by evaluating the ratio between the current flowing into and out of the protective device. When this ratio exceeds a predetermined limit the protective relay evaluates the difference between the current flowing into and out of the device to determine if this difference is sufficiently large to trip the relay. When a current transformer associated with the differential protective relay is saturated, the differential protective relay produces a restraint signal to restrain tripping.

System driven by solar energy for pumping liquids

Abstract: A system converting solar energy into electric power for driving an electro-mechanical pump to pump liquid by processing electric power furnished by solar cells of variable level, which includes converting the solar energy into pulses of constant electric power, the pulses spaced from one another as a function of the level of solarization.

Vertical-axis wind turbine development in Canada

Abstract: Recent Canadian progress in the development of the curved-blade Darrieus vertical-axis wind turbine (VAWT) is described. Co-operation between government, industry and power utilities in the conduct of field trials, over several years, has demonstrated inproved performance and reliability of grid-coupled turbines of this type. The rated power of the VAWTs currently under test ranges from 30kW, in a wind/diesel powerplant, to 230 kW, in an installation on an island in the Gulf of St. Lawrence. Progress has also been made in understaning the basic aerodynamic behaviour of the VAWT and theoretical methods for performance and load prediction have correspondingly improved. A brief description is given of `Project EOLE', a co-operative project between the federal government and the utility Hydro-Quebec to develop and test, during the next two to three years, a 4 MW VAWT prototype, which will be coupled to the power grid at a location on the south shore of the St. Lawrence River.

Regulator system for a diesel electric locomotive

Abstract: A regulator system for both the Diesel and the electric portions of a Diesel electric locomotive allowing more reliable operation at all locomotive speeds. Said regulator has a regulator to regulate the electric power by varying the excitation (43) of the main generator by means of orders coming from a driver control (1, 8) which set a reference current level and (17) a voltage reference level (19) for the main generator and a Diesel engine gas oil reference level (18). These levels are compared with measurements of true corresponding values (24, 30, 27) and orders (43) for increasing or decreasing excitation are delivered so that the excitation of the main generator remains inside the scope delimited by the various reference levels and a Diesel power regulator which sends out orders to increase or decrease the gas oil injection in accordance with a predetermined Diesel engine speed/injection law and in comparison with the true measurements of the injection and of the Diesel engine speed.

Catastrophe Theory as a Tool for Determining Synchronous Power System Dynamic Stability

Abstract: A mathematical method, Catastrophe Theory, is applied to the problem of electrical power system dynamic stability. It is suggested that this offers a method for the continual monitoring of power system stability margins by the use of visual graphic display produced by a dedicated minicomputer using information monitored from the power system.

Magnetic disk device

Abstract: PURPOSE:To reduce the power consumption and then the calorific power, by providing a switch means between a power supply device and a magnetic disk driver and supplying the electric power only for an access. CONSTITUTION:Switch means 20A-20D are inserted to power supply lines of control and driving systems provided between a power supply device 1 and two disk drivers 4 and 5. These switch means 20A and 20B as well as 20C and 20D of the drivers 4 and 5 are controlled by a controller 6. These switch means are driven at one time when the drivers 4 and 5 give the read/write accesses to a magnetic disk. Then the controller 6 selects the access of drivers 4 and 5 respectively.

Load Following Impacts of a Large Wind Farm on an Imterconnected Electric Utility System

Abstract: A major issue encountered in the use of many of the renewable energy resources for the production of electric power is the variability of the resource itself. This paper presents the results of a dynamic simulation of the long term power system responses to changes in the load and generation patterns resulting from significant penetrations of renewable resource technologies. The renewable technology selected for this study is a large wind farm with a total output of 500 MW added to the 1979 generation base of the Los Angeles Department of Water and Power system.

System for producing and distributing electrical energy for vehicles particularly aircraft, as well as an electrical power center for such a system

Abstract: In a system including an electrical power center for producing and distributing electrical energy for vehicles, particularly aircraft, primary circuit breakers and contactors are distributed between a D.C. electrical power center, relay boxes, electronic bays and control panels and the electrical power center forms a central unit grouping together different protection or safety devices. The system permits the electrical network on board an aircraft to be simplified and lightened.

Power switching apparatus

Abstract: A switching device that relates to the arrangement of a switching network for use within an electrical power distribution system. There is an improved security of power delivery to various loads while at the same time enabling a reduction in the number of required circuit breakers and related gear. This network also presents additional options in design and operating modes, when applied to distribution systems. These options result in a reduction in the total installed capacity of the sources together with reduced continuous current and fault current ratings of conductors and interconnected apparatus. The invention provides a switching network has six conducting branches, each branch containing at least one switching means such as a circuit breaker. The branches are connected at their ends to form four 3-sided rings, each branch forming a side of and being shared by two of the rings. As a result, four triple-connected nodes are formed at the end connection points of the branches while the connections between adjacent pairs of switching device within a branch form double-connected nodes. These nodes serve as points for connection thereto of source/load elements, and each node is isolatable from the other nodes by the opening of a maximum of three of the switching device.

Apparatus for controlling an A-C powered elevator

Abstract: An apparatus for controlling an A-C powered elevator wherein: when a frequency instruction value lies within a predetermined frequency range, an inverter in the apparatus produces an A-C electric power having a frequency which lies outside said predetermined frequency range, so that the frequency of the electrical power supplied from said inverter to the motor driving an elevator cage will be out of the resonant frequency range of the mechanical system of the elevator. Namely, an inverter is connected to a D-C power supply, the inverter is controlled by a voltage instruction value and a frequency instruction value, a D-C electric power is converted into the A-C electric power having a variable voltage and a variable frequency by said inverter, and an A-C electric motor is powered by the thus converted A-C electric power to drive an elevator cage, wherein a frequency conversion computer is provided which, when said frequency instruction value lies within a predetermined frequency range, sends to said inverter a frequency instruction value which lies outside said frequency range.

Steam optimization and cogeneration system and method

Abstract: In a multiturbogenerator cogeneration system mass flow balancing is used to optimize the distribution of steam between the machine while meeting the demand in steam and electrical power of the industrial plant in order to choose the less costly between cogenerated power and power purchased from the tie-line. The EVOP method of optimization is used off-line with the assist of a microcomputer to determine the optimal distribution of steam.

The Electric Power Research Institute

Abstract: The Electric Power Research Institute, now 10 years old, was formed by the electric utility industry in response to the threat of federal legislation to create a government agency, funded by a 1 percent tax on utility gross revenue, to undertake research and development. Legislation was proposed in the early 19709s by the Senate Commerce Committee as a result of the massive 1965 Northeast blackout and subsequent public criticism. In March 1972, the Senate was persuaded to give the electric utility industry 1 year to establish an industry-managed and supported substitute to the proposal. This article describes the subsequent history and the program today.

Considerations in Developing and Utilizing Operator Training Simulators

Abstract: Effective electric system operation depends on strengthening the relationship between the system operator and the electrical system with its associated control system. This relationship can be developed through a training medium which increases the operator's knowledge of the behaviot of the power system under various operating conditions and contingencies, and its response to control actions. An Operator Training Simulator (OTS), which simulates the static and dynamic responses of the operator's power system and his control system, can accomplish these training objectives. The concepts developed in this paper are based on the work of the project team through funding by the Electric Power Research Institute.

Experimental study of power system stabilization by superconducting magnetic energy storage

Abstract: Superconductive Magnetic Energy Storage (SMES) is one of the effective measures to suppress system instabilities in electric power networks because of its fast response at exchanging electric power. Two types of experiments, dynamic and transient, have been performed to suppress instabilities by using an SMES unit on a model power system. The test system has a 60 kVA synchronous generator, a double-circuit transmission line connected to an infinite bus, and an SMES unit with an SCR converter. They simulate a salient pole synchronous generator of 600 MVA and a transmission line of 275 kV with 380 km in length. The SMES unit whose maximum stored energy is 100 kJ can exchange energy matched with the model system. The SMES unit could effectively suppress these instabilities by exchanging energy.

Home demand controller

Abstract: A demand controller uses a sensor to detect the operation of an electric load. The sensor operates a relay which supplies power to a magnetic contactor. The magnetic contactor controls power available to a second electric load so that the total amount of power consumed is held below a predetermined maximum. An auxillary switch operates in conjunction with the magnetic contactor to control power available to other loads. A hierarchy is established so that the most important load always has power available, and loads of lesser importance are controlled.