Showing papers on "Power module published in 1985"

A United Approach to Optimal Real and Reactive Power Dispatch

Abstract: This paper presents a unified method for optimal real and reactive power dispatch for the economic operation of power systems. As in other methods, the problem is decomposed into a P-optimization module and a Q-optimization module, but in this method both modules use the same generation cost-objective function. The control variables are generator real power outputs for the real power module; and generator reactive power outputs, shunt capacitors/reactors, and transformer tap settings for the reactive power module. The constraints are the operating limits of the control variables, power line flows, and bus voltages. The optimization problem is solved using the gradient projection method (GPM) which is used for the first time in the power systems study. The GPM allows the use of functional constraints without the need of penalty functions or Lagrange multipliers among other advantages. Mathematical models are developed to represent the sensitivity tivity relationships between dependent and control variables for both, real and reactive power, optimization modules, and thus eliminate the use of B-coefficients. Results of two test systems are presented and compared with conventional methods.

Electrical Engineer's Reference Book

Abstract: General principles materials power generation transmission and distribution power systems electricity utilization - power control and conversion electricity utilization - materials treatment electricity utilization - environmental electricity utilization - transportation.

Power control network for multiple digital modules

Abstract: A power network control system has a plurality of digital modules interconnected. A master logic unit in the network' communicates with a specialized protocol to slave logic units in each module. The slave logic unit can instruct a power control circuit to turn-off or turn-on various power supply modules in addition to adjusting a power module in steps of plus or minus fixed percentage amounts.

Fault-tolerant power distribution system

Abstract: A fault-tolerant power distribution system which includes a plurality of power sources and a plurality of nodes responsive thereto for supplying power to one or more loads associated with each node. Each node includes a plurality of switching circuits, each of which preferably uses a power field effect transistor which provides a diode operation when power is first applied to the nodes and which thereafter provides bi-directional current flow through the switching circuit in a manner such that a low voltage drop is produced in each direction. Each switching circuit includes circuitry for disabling the power field effect transistor when the current in the switching circuit exceeds a preselected value.

Study of a resonant converter using power transistors in a 25KW x-rays tube power supply

Abstract: This paper describes a converter whose purpose is to feed an χ-rays tube (25 KW, 140 KV) from the industrial main power supply (380 V, 50 Hz). The authors justify the structure of this generator that is constituted by an inverter using power transistors and a transformer-voltage multiplier set which are connected by a series resonant circuit. The control logic of the transistors gives them the dual properties of these of thyristors. An accurate analytical study of this system allows to predetermine the characteristics of this converter now in its industrialization phase.

Transistorized power supplies for induction heating

Abstract: In the last five years power MOSFETS have become available which have good radio frequency capability, low drive power requirements and ease of paralleling for higher power output. An induction heating power supply using power MOSFETS as switches is more efficient, is more easily controllable and has a lower capital cost than a valve supply, and the MOSFET power supply is not limited in frequency as thyristor supplies are. This paper gives details of three different types of transistorized power supplies developed for induction heating applications and compares their performances.

Power sensing device

Abstract: A power sensing device is disclosed for use with an electrical alternating current (AC) power source, a primary load, and a plurality of secondary loads. The power sensing device detects when the primary load is turned on, and automatically supplies power from the electrical AC power source to the plurality of secondary loads in response thereto. The power sensing device also senses when the primary load is turned off, and removes electrical power from the plurality of secondary loads in response thereto.

The Q.U.B. Axisymmetric and Multi-Resonant Wave Energy Convertors

Abstract: This paper describes the optimization of the power conversion chain and the engineering design considerations of an oscillating water column wave power device which would form part of a 2-GW power station. Novel features of the principal device described include the multi-resonant concept, which considerably widens the frequency bandwidth response, and the use of the simple highly efficient Wells self-rectifying air turbine in the secondary power conversion stage. It is concluded that using established technology wave power stations comprising sea bed mounted reinforced concrete structures could produce power for as little as 1.3p per kW-hr after the initial capital repayment period and thus the economics are similar to that of hydro-electric power.

Plug-in power module for electrostatic air cleaner

Abstract: A power module for an electrostatic air cleaner in which an electronic power supply circuit and its components are enclosed within a relatively small modular housing having an AC voltage input in the form of plug-in blades particularly adapted to be inserted within a standard or conventional AC electrical outlet, and a cable for transmitting the high-voltage DC output from the housing to the air cleaner.

Pulsed power packs a punch: Lasers, electromagnetic launchers, and fusion reactors require enormous, instantaneous pulses of power not available from the utilities' mains

Abstract: For many applications, power must be derived in short, huge bursts. To deliver this pulsed power, energy must be collected at low power, stored, and then released almost instantaneously. The author details the linking of capacitors and inductors and explains how the pulse is created. Attention is given to a specialized variant of pulse generation whereby capacitors and inductors make use of explosives to compress magnetic flux in inductive energy stores. The advantages and drawbacks of batteries, flywheels, and DC and AC machines are also discussed.

High Power Distributed Amplifier Using MBE Synthesized Material

Abstract: The main limitations of the output power of a distributed amplifier are the gate line loss and the gate-to-drain breakdown voltage. A novel circuit concept to reduce the gate loss using series capacitors on the gate feeding lines has been implemented. The device breakdown voltage has been improved by using an MBE grown material with two layers (low doped gate buffer layer and usual active layer). A monolithic GaAs distributed amplifier using 6 x 300 µm FETs has achieved an output power of 800 mW with 4dB gain. The power added efficiency was about 15%.

State of the Art in DC-to-DC Converters

Abstract: The switching regulator is a power supply in which the output voltage is regulated by ON and OFF processes of a power semiconductor element. This regulator has been used widely in almost all electronic equipment because of its small size and low power dissipation. However, switching regulators in use now do not always seem to be compatible with highly integrated electronic devices, as it is very difficult to apply IC techniques to such regulators. Even if the latest electronic techniques are used, switching regulators are still too large, too complicated and not always sufficiently reliable. In order to reduce the size of such regulators, the switching frequency should be made as high as possible. This means that the switching loss of the semiconductor and the core loss of the transformer and reactor should be low. The effective use of magnetic components will provide the solution for raising frequencies as well as making switching regulators more simple and reliable. In this paper, we describe the state of the art of switching regulators, and future trends in applications of magnetic components.

Development of an Organic Rankine-Cycle power module for a small community solar thermal power experiment

Abstract: An organic Rankine-cycle (ORC) power module was developed for use in a multimodule solar power plant to be built and operated in a small community. Many successful components and subsystems, including the reciever, power conversion subsystem, energy transport subsystem, and control subsystem, were tested. Tests were performed on a complete power module using a test bed concentrator in place of the proposed concentrator. All major single-module program functional objectives were met and the multimodule operation presented no apparent problems. The hermetically sealed, self-contained, ORC power conversion unit subsequently successfully completed a 300-hour endurance run with no evidence of wear or operating problems.

Power supply control device

Abstract: A power supply control device is usable in a battery-driven electronic device, in which a power down mode is adopted when the battery is mounted.

Down hole power conversion means for fully utilizing batteries

Abstract: A self-contained, down hole powered electrical system in which the available power of a battery source is matched by a power conversion means to the power required in the down hole equipment and the power conversion means provides a regulated voltage output.

Compact power supply module and cord

Abstract: A product such as a portable radio adapted for operation from either an internal battery source or an external source of relatively high voltage alternating current electric power is provided with a removable power module containing all of the high voltage components required for operation from the alternating current source. The removable power module is connected to the product by a low bulk, low voltage electrical connector through a recess in the product housing, the recess being sized to receive both the power module and the electrical connector when battery operation is desired. Because of the low bulk of the electrical connector, the size of the recess may be minimized.

Leasecraft Power System Leasecraft Power System

Abstract: Various building blocks of the Fairchild Leasecraft Power System are described in detail after a brief description of the evolution of the Leasecraft spacecraft. The principle of maximum power transfer from a solar cell array has been employed in the power system advantageously. Results of detailed tradeoff studies are presented which led to the selection of the decentralized regulation concept utilizing a nondissipative unregulated main (power) bus approach. Finally the main features of the Leasecraft Power System, i.e., flexibility, reliability, input and output electrical characteristics, etc. are presented.

Electric power supply device.

Abstract: This device for powering N user modules Un comprises N power sources Sn, the power to the user module Un being concurrently provided by power sources Sn and Sn-1, which makes it possible, through mutual assistance between the various power sources, to solve the problems of user module overload or of power source failure. Application in particular to the powering of telephone switching equipment.

Test results of an organic Rankine-cycle power module for a small community solar thermal power experiment

Abstract: The organic Rankine-cycle (ORC) power conversion assembly was tested Qualification testing of the electrical transport subsystem was also completed Test objectives were to verify compatibility of all system elements with emphasis on control of the power conversion assembly, to evaluate the performance and efficiency of the components, and to validate operating procedures After 34 hours of power generation under a wide range of conditions, the net module efficiency exceeded 18% after accounting for all parasitic losses

Performance analysis of radiation cooled dc transmission lines for high power space systems

Abstract: As space power levels increase to meet mission objectives and also as the transmission distance between power source and load increases, the mass, volume, power loss, and operating voltage and temperature become important system design considerations. This analysis develops the dependence of the specific mass and percent power loss on hte power and voltage levels, transmission distance, operating temperature and conductor material properties. Only radiation cooling is considered since the transmission line is assumed to operate in a space environment. The results show that the limiting conditions for achieving low specific mass, percent power loss, and volume for a space-type dc transmission line are the permissible transmission voltage and operating temperature. Other means to achieve low specific mass include the judicious choice of conductor materials. The results of this analysis should be immediately applicable to power system trade-off studies including comparisons with ac transmission systems.

Technology Trends for Telecommunications Power in the United States

Abstract: This paper presents an overview of the trends in telecommunication system power unit design and improvements to be incorporated into these designs in the future. The need for better power unit component materials and reliability, the advantages of increasing switching frequency and higher rates of forced-air cooling are discussed.

Principle of Tracking of the Static Power Frequency Changers using Moments

Abstract: The paper considers some aspects of tracking of the output current standard of the Static Power Frequency Changers. The problem lies in the right choice of the one voltage phase of the network. Such a choice is based on prediction of the current of the loading. Discussed predicting control minimize the interval-by-integral quality index and the number of the commutations of the switching semiconductors. The paper also presents the properties of the moments and momentary transformation which facilitates such a control.

Design of high-voltage, high-power, solid state remote power controllers for aerospace applications

Abstract: Two general types of remote power controllers (RPC's), which combine the functions of a circuit breaker and a switch, were developed for use in dc aerospace systems. Power-switching devices used in the designs are the gate-turnoff thyristor (GTO) and MOSFET. The RPC's can switch dc voltages to 1200 V and currents to 1000 A. Seven different units were constructed and subjected to laboratory and thermal vacuum testing. Two of these were dual units that switch both positive and negative voltages simultaneously. The RPC's using MOSFET's have slow turnon and turnoff times which limit surge currents and voltage spiking from high di/dt. The GTO's have much faster transition times. All RPC's have programmable overload tripout proportional to I sq T and microsecond tripout for large overloads.