Showing papers on "Electric power published in 1986"

Analysis of Electric Machinery

Abstract: Originally published in 1986 by McGraw-Hill. Focusing on the areas of electric power and electric drives, this advanced text and industry reference emphasizes analysis and formulation for control applications and computer simulation. Annotation copyright Book News, Inc. Portland, Or.

Electric steering gear

Abstract: An electronic control system for a steering assembly having an electric motor coupled to the steering assembly for providing power assist. The electric power assist motor is drivably connected to a steering member for assisting movement thereof in response to applied input torque to the vehicle steering wheel. The electronic control unit monitors an output signal from a torsion sensor which measures the amount of applied input torque. The electronic control unit generates a pulse width modulated signal having a duty cycle proportional to the measured amount of applied input torque. Solid state switches provide connection between the vehicle battery and the motor, the connection time being controlled by the duty cycle of the pulse width modulated signal. A speed decoder determines which of a plurality of speed ranges the vehicle is moving. A plurality of look-up tables are provided, each table includes a value of power assist for a given amount of applied input torque. A look-up table is selected depending upon the decoded vehicle speed. Soft start circuitry is provided to control the maximum amount of assist that is permitted upon initial application of power to the electronic control unit. The amount to assist permitted increases from a minimum to a maximum within a predetermined amount of time. Temperature foldback circuitry is also provided to limit the amount of current through the electric power assist motor dependent upon sensed temperature of the solid state switches. The amount of current permitted through the motor is also limited to an absolute maximum. A connection cable is provided to reduce radiated electromagnetic emissions and voltage transients.

Pipeline built-in electric power generating set

Abstract: An electric power generating set for a fluid pipeline, comprising a turbine coupled to the pipeline for rotating under the pressure of the fluid moving in the pipeline; a generator coupled to the downstream end of the turbine for generating electric power upon rotation, and a heat exchanger for communicating the fluid from the turbine to the pipeline for absorbing heat from the generator.

Economies of density and size in the production and delivery of electric power.

Abstract: Recent proposals for regulatory reform in the electric power industry have emphasized the potential for competition among generating facilities but have been less optimistic about the role of market forces in the delivery of electric power. The possibility that there exist significant scale economies in the transmission and distribution of electricity has led to arguments that all, or some, of the components of the delivery system should continue to be regulated regardless of any regulatory changes at the generation level. While the technology of electric power generation has been examined in detail, the magnitude of scale economies in the transmission and distribution of electricity is less clearly understood. The difficulty with analyzing scale effects in industries which deliver a product to a spatially dispersed group of customers, such as electricity, cable television, water, or natural gas, is that output expansions can occur in several different ways. Increased demand by existing customers, demands by new customers within the firm's service area, or an expansion of the service area can all lead to increased output but each can have a different impact on unit cost and thus lead to a different measure of scale effects. This paper develops three measures of economies of density and size which are useful in analyzing the cost structure of firms which must deliver their output to geographically dispersed customers. The measures, which recognize the different ways in which output changes can occur, are used to analyze firm differences in the average cost of supplying electric power. The empirical results indicate that the important source of declining ray average cost is an increase in the quantity of output consumed per customer and not an increase in customer density or service area size. On average, a 1 percent increase in output, holding both the number of customers and service area fixed, leads to a .82 percent increase in total cost. If the increased output results from an increase in the number of customers, as would happen in an area with a growing population, there is no substantial decline in the average cost of delivered power. A one percent increase in both output and number of customers, which keeps consumption per customer constant, results in a .98 percent increase in total cost. On average, there are no significant economies resulting from increased customer density. This occurs because the decline in average cost due to the increase in output is offset by an upward shift in the average cost function resulting from the increase in the number of customers. One implication of competing firms in a given service area is a decline in customer density and this finding suggests that substantial efficiency losses would not occur as a result.

Peak power shaving apparatus and method

Abstract: Utility charges associated with peak electrical power demands constitute an increasing portion of utility bills associated with large commercial consumers of electricity. The instant invention provides an apparatus for reducing the peak electrical demand of a predetermined user operational unit from an electrical power distribution network by controllably operating at least one secondary electrical generator associated with the operational unit in parallel with the utility power distribution network. The secondary electrical generator includes a switch for connecting the generator in parallel with the utility network in response to receiving a transfer command signal. A transducer senses the actual peak power demand of the operational unit from the utility network and produces a demand signal having a value responsive to the sensed actual peak power demand. A memory element controllably stores a plurality of control parameters including a demand setpoint value. A logic device controllably produces the transfer command signal and connects the secondary electrical generator in parallel with the utility distribution network in response to the value of the demand signal exceeding the value of the demand setpoint. The logic device controls the secondary electrical generator to produce only the amount of power necessary to maintain the demand signal at or below the demand setpoint value.

Load current management system for automotive vehicles

Abstract: An electrical power delivery system and method of operation particularly suitable for use in a vehicle is disclosed. A single wire power conductor is connected through remote power switches to a plurality of loads. The power conductor is sized such that its current-carrying capacity is less than the current required to simultaneously operate all the loads connected thereto. Logic means are provided for delivering a control signal to the remote power switches to selectively energize the appropriate loads. The logic means additionally includes means responding to excess current flow through the power conductor to schedule the control signals to prevent simultaneous operation of all the loads thereby limiting current flow through the power conductor to its current-carrying capacity.

Novel process for direct conversion of free energy of mixing into electric power

Abstract: Direct conversion of salinity gradients into electric power as well as production of an acid and a base, simultaneous to generation of electricity, was investigated. Devices that combined features of an electrodialytic pile with those of fuel cells or of electrochemical half cells were designed. Electrodes of the electrochemical half cells were restored to their initial condition by simple reversal of the flow pattern. Fuel cells in the investigated system used water as the fuel and air as the oxidant. Energy extracted from salinity gradients at power density of up to 1 W/m/sup 2/ of the membrane yields up to 0.6 MW of electric power per m/sup 3//s of river or brackish water. Sodium hydroxide is obtained in an amount which corresponds to the number of coulombs of electricity generated in the process. Part of the produced HCI is, however, lost.

Semiconductor memory device

Abstract: PURPOSE:To avoid the vanishing of data when an obstacle occurs during operating the device by having plural control parts which is independent and can access to respective memory parts. CONSTITUTION:When an obstacle occurs at an electric power supply part 27, the functions of a control part 21, memory parts 23 and 24 are stopped. The data stored in the memory part 23 are simultaneously written and stored in a sub-memory 25 corresponding to the positive memory part 23 by the double writing means. For that reason, by accessing the memory part 25 by other one control part 22, the same as the data in a memory part 23, in which the function stops, is read. When the obstacle occurs at the memory part 23, by reading the memory part 25 with the control part 21, the same as the data in the memory part 23, in which the function stops, is read. At the time of the obstacle of the memory part 25, the control part 21 will not be influenced due to the obstacle.

Power generating optical filter

Abstract: A power generating optical filter (30) specially tuned to (1) transmit at least portions of selected wavelengths of incident light and (2) generate electrical power from absorbed portions of selected wavelengths of incident light. FlG.

Thermoplastic fitting electric heat welding method and apparatus

Abstract: A method and apparatus for electrically heat welding a thermoplastic fitting having an electric resistance heating element disposed therein whereby a regulated quantity of electric power is supplied to the heating element during the welding process and the making of a high quality weld is insured. In accordance with the method, a controlled electric power is supplied to the resistance heating element of the fitting. The initial magnitude of the current flowing through the heating element is sensed and compared with predetermined current levels for various sizes of fittings whereby the size of the fitting as well as the total time the controlled electric power should be supplied to the heating element of the fitting for the making of a high quality weld are determined. The magnitude of the current flowing through the heating element over the time the controlled electric power is supplied thereto is sensed at predetermined time intervals and compared with predetermined current levels for the size of fitting being welded to thereby determine if the welding process is proceeding abnormally at such time intervals. The electric power supplied to the heating element is terminated when it is determined that the welding process is proceeding abnormally or otherwise at the end of the total time determined to be required for the making of a high quality weld.

Method and means for parking read/write heads in a disc drive using the back-EMF of the spindle motor to operate a stepper motor

Abstract: Electronic circuitry is provided to position the read/write heads in a designated landing zone when the electrical power is removed from the drive. When power is removed from the drive, the stored energy of the rotating spindle motor is used as a source of electrical power and timing pulses to the stepper motor which drives the actuator of the disc drive. The power generated by the spindle motor as it spins down is referred to as "back EMF." A sequencer circuit is provided to couple the power and clock pulses to selected windings of the stepper motor to cause the stepper motor to rotate in the direction necessary to move the transducer heads to a predetermined park position at the inner diameter of the disc whenever power is removed from the disc drive. Since the location of the heads at power down may not be known, the timing of the pulses is such that a sufficient number of steps will be taken to move the transducer heads to the parking zone within the time alloted even if the heads were at the outermost track. Step pulses will continue to be generated until the back EMF of the spindle motor is insufficient to generate such pulses. After the transducer heads are at the predetermined parking location, any additional steps will cause the actuator to contact a mechanical "inner crash stop" designed to prevent damage to the transducer heads from contact with the clamp which retains the discs.

Semiconductor storage device

Abstract: PURPOSE:To prevent an abnormal current at the time of turning on an electric power source by making an input signal repeating change termination detecting circuit detect that an input wall not change during a certain period after outputs of an input signal change detecting circuit are syntheszed and setting forcibly the timing circuit of an internal synchronizing type in the preset internal state CONSTITUTION:The input signal repeating change termination detecting circuit 3 is constituted of an integrating circuit 4, a discharging circuit 5 and a voltage comparat or circuit 6, and is the output of a synthesizing circuit 2 for synthesizing input signal change detecting signals applied to input signals The pulse of the input signal change detecting signal is integrated in capacity, and simultaneously an electric charge is discharged by a discharging circuit 5 When an input change pulse does not arise over a certain period, a charged electric charge amount is larger than a discharged electric charge amount to change an inter-capacity voltage Then the voltage compara tor circuit 6 detects that the input change disappears over a certain period The voltage comparator circuit output sets forcibly the internal state of an internal timing generat ing circuit 7 Accordingly, when the input singal does not change over a certain period (includes the time when the power source is turned on), the internal state of an integrat ed circuit can be forcibly initialized

Apparatus and method for supplying electric power to cable suspended submergible pumps

Abstract: Electric power is supplied to downhole equipment, such as a submergible pump, by a power cable that is joined to a support cable by a cable carrier as the carrier and cables are fed into a well. The carrier comprises laterally displaced resilient clamping sections that are clamped about respective cables to form a continuous assembly, and the assembly is fed into the well as the equipment is installed.

Apparatus to indicate when a patient has evacuated a bed

Abstract: A monitoring system for a bed patient comprising a binary signal generating means to provide a first signal when the patient is in the bed and a second signal when the patient is out of the bed. An alternating electrical power supply passes to a frequency divider so that electrical pulses of selected time spacing are derived by means of which time can be measured. These pulses go to a signal delay means with adjustments possible for any selected delay and then to a latch means. Alarm control means are provided responsive to the operation of the latch for controlling the nature of the alarm signal. The alarm control means alternately provides electrical alarm signals of various sorts, such as a single short pulse or an indefinitely long pulse or an alternating signal. Each of these could separately control a visual or audible alarm means. This invention is compatible with normal call equipment and alarms in hospitals.

Electric machine dynamics

Abstract: Boldea and Nasar present a treatment of electric machine dynamics pertaining to modern static-power electric drives and electric power generators. They introduce a mathematical approach (such as that based on the orthogonal axis machine model), and include numerous examples that illustrate the analysis methods discussed. CONTENTS: Fundamentals of Electromechanical Energy Conversion. Electric Machine Models. DC Commutator Machines. Synchronous Machines. Induction Machines.

Gravity and buoyancy driven power generators

Abstract: An apparatus which generates electrical power from a combination of gravity forces and the inherent buoyancy of a hollow body immersed in a fluid is disclosed. The apparatus includes a long chain having a plurality of hollow buoyant elements attached thereto. The chain extends around a pair of sprockets and the buoyant elements are immersed in a fluid along the portion of the chain moving against gravity and the buoyant elements pass through an airspace along the portion of the chain moving with gravity. The combination of buoyancy and gravitational forces cause movement of the chain to thereby rotate the sprocket gears which are used to drive an electrical power generator. Also disclosed is a housing including a hatch assembly for the apparatus and a valve unit and an insulator for use with the apparatus.

Fuel cell power generating system

Abstract: A fuel cell power generating system is disclosed in which fuel cells are able to operate with satisfactory and stable cell characteristics for a long period of time even at a high fuel utilization ratio, and which has a high power generating efficiency and a long lifetime The fuel cell power generating system includes a first fuel cell adapted to be supplied with a fuel gas containing water vapor and an oxidant gas which are subjected to electrochemical and/or chemical reactions for generating electric power, and a second fuel cell adapted to be supplied with the exhaust gas from the first fuel cell and an oxidant gas which are subjected to electrochemical and/or chemical reactions for generating electric power The humidity of the exhaust gas fed from the first fuel cell to the second fuel cell is appropriately regulated in a manner such that the exhaust gas containing therein an appropriate amount of water vapor is fed to the second fuel cell so as to prevent carbon deposition in the second fuel cell To this end, a surplus amount of water vapor is removed from the exhaust gas from the first fuel cell

Retrofit SO2 and NOx control technologies for coal‐fired power plants

Abstract: The United States currently depends on coal for over half of its electric power generation. Current legislative and regulatory initiatives related to acid rain and other environmental concerns have focused on retrofit controls on existing plants and increasingly stringent requirements for new plants. This paper focuses on some of the technological approaches United States utilities are using and could be using in the future to generate electric power cleanly and reliably. Those technologies discussed include precombustion controls (physical coal cleaning and coal switching/blending), combustion controls (low NOx combustion, furnace sorbent injection, and fluidized bed combustion), and postcombustion controls (flue gas NOx control, wet and dry flue gas desulfurization, and post-furnace dry sorbent injection) The commercial status, economics, and critical issues for retrofit and new commercial application of these technologies to utility systems are discussed.

Inverter system for inputting alternating current and direct current in combination

Abstract: An inverter system is disclosed for inputting an alternating current and a direct current in combination. This inverter system comprises an AC-DC converter to convert a received AC electric power from an AC electric power source to a DC electric power; a DC-AC converter to convert a thus converted DC electric power and a DC electric power from a DC electric power source to an AC electric power; a first switching means to open or close an electric circuit between an output side of the DC-AC converter and a first load; a second switching means to open or close an electric circuit between the AC electric power source to which a second load is connected and the output side of the DC-AC converter; and a controlling means for controlling opening and closing of the first and second switching means. When a electric power consumption of the first load is larger than an output of the DC electric power source, the controller closes the first switching means and opens the second switching means. When an operation of the first load is stopped, the controller opens the first switching means and closes the second switching means. When the electric power consumption of the first load is smaller than the output of the DC electric power source, the controller closes both the first and second switching means.

Power indicator light

Abstract: An improved female electrical receptacle connected to an electrical power extension cord has a power indicator light to signal that the extension cord has power.

Electrical power terminal for circuit boards

Abstract: An electrical terminal for connecting a power supply section (35) to a circuit board (50) which requires no tools and utilizes minimal space on the circuit board (50). The terminal having mounting pins (14) which frictionally and electrically engage holes (30 in the circuit board (50) and a contact portion (18) which resiliently contact the power supply section (35), thereby effecting a positive electrical connection between the power supply section (35) and the circuit board (50).

Air conditioning apparatus and control method thereof

Abstract: An air conditioning apparatus includes a variable frequency power source device for providing an AC electric power with a variable frequency, a variable capacity compressor driven by the AC electric ipower and a starting detector for detecting a starting state of the compressor a predetermined time after the compressor is energized. When the starting detector detects the starting failure of the compressor, the variable frequency power source device feeds the compressor with a starting frequency voltage until the starting detector detects changes in the level of the input current to the compressor within a predetermined time to heat refrigerant in the compressor, and then feeds the compressor with a driving frequency voltage corresponding to the required air conditioning load. When no change in the level of the input current is detected within the predetermined time, the variable frequency power source device supplys the compressor with the driving frequency voltage immediately after the predetermined time elapsed.

Household appliance for making frozen food products

Abstract: An appliance for making ice cream as well as other frozen or chilled food and beverage products, motive power for the appliance being supplied thereto by the existing electric power base unit of a standard household blender. This standard unit includes a motor whose shaft extends upwardly through a platform having a cage or socket thereon to accommodate a blender bowl, the shaft terminating in a drive coupler. The appliance is constituted by a bowl assembly whose bottom section is embraced by a ring adapted to be received in the socket of the power base unit. Above the bottom section is a double-walled jacket whose cavity contains a freezable agent. Supported for rotation in the bottom wall of the assembly and extending therethrough is a short axle whose lower end terminates in a driven coupler that is engaged by the drive coupler of the power base unit when the ring of the assembly is nested in the cage, the upper end of the axle being coupled to a dasher rotatable within the assembly. In practice, the bowl assembly is first stored in an available freezer for a period sufficient to freeze the agent therein. It is then taken out of the freezer, filled with ingredients to be frozen or chilled and placed on the power base unit. When the motor is turned on, this causes the rotating dasher to mix the ingredients while they are concurrently being chilled by heat transfer from the jacket.

Apparatus for controlling electric clothes dryer and method therefor

Abstract: Disclosed is an apparatus for controlling an electric clothes dryer having an electrical heater arranged to be supplied with electric power from a power source to generate heat so as to dry clothes by air heated by the heater, the apparatus comprising a switching device for opening/closing an electrical connection between the power source and the heater in response to a control signal, a voltage detecting circuit for detecting a voltage of the power source and for generating an overvoltage signal when the detected voltage exceeds a predetermined value, and a control signal generating circuit responsive to the overvoltage signal for generating the control signal for turning on/off the switching device. The control signal is formed so that the opening period of the switching device corresponds to the value of the overvoltage signal. Further, the opening period of the switching device is selected the value of power consumption per unit time of the heater always becomes a predetermined value in the case where the supply of power to the heater from the power source is stopped during the opening period of the switching device.

Solar power generation system

Abstract: PURPOSE:To improve the operation efficiency of a solar battery by utilizing excessive electric power as a pump power source. CONSTITUTION:The series circuit of a chopper 10 and a DC motor 11 for pump driving is connected to a DC circuit at an inverter input side in parallel and the current obtained by subtracting an inverter input current corresponding to load electric power and the charging current of the solar battery 4 from the output current of a solar battery array 2 is shunt to said parallel circuit in a time zone in which excessive electric power is generated. The voltage- current characteristic of the solar battery array 2 varies with the quantity of solar radiation, but a voltage VP at which maximum electric power is obtained is nearly constant, so the output current of the solar battery array is only controlled so as to obtain the voltage VP, thereby obtaining maximum electric power corresponding to the quantity of solar radiation from the solar batteries. Specially, when the quantity of solar radiation is large and a storage battery 4 is charged to its limit, the excessive electric power is large, but this is utilized as the driving electric power of a motor-driven pump to realize operation with the maximum electric power of the solar battery array.