Showing papers on "Power module published in 1989"

Power Electronics: Converters, Applications and Design

Abstract: Partial table of contents: Overview of Power Semiconductor Switches Computer Simulation of Power Electronic Converters and Systems GENERIC POWER ELECTRONIC CIRCUITS dc--dc Switch-Mode Converters Resonant Converters: Zero-Voltage and/or Zero-Current Switchings POWER SUPPLY APPLICATIONS Power Conditioners and Uninterruptible Power Supplies MOTOR DRIVE APPLICATIONS dc Motor Drives Induction Motor Drives Synchronous Motor Drives OTHER APPLICATIONS Residential and Industrial Applications Optimizing the Utility Interface with Power Electronic Systems SEMICONDUCTOR DEVICES Basic Semiconductor Physics Power Diodes Power MOSFETs Thyristors Emerging Devices and Circuits PRACTICAL CONVERTER DESIGN CONSIDERATIONS Snubber Circuits Gate and Base Drive Circuits Design of Magnetic Components Index

Power semiconductor device figure of merit for high-frequency applications

Abstract: A figure of merit (the Baliga high-frequency figure of merit) is derived for power semiconductor devices operating in high-frequency circuits. Using this figure of merit, it is predicted that the power losses incurred in the power device will increase as the square root of the operating frequency and approximately in proportion to the output power. By relating the device power dissipation to the intrinsic material parameters, it is shown that the power loss can be reduced by using semiconductors with larger mobility and critical electric field for breakdown. Examination of data in the literature indicates that significant performance improvement can be achieved by replacing silicon with gallium arsenide, silicon carbide, or semiconducting diamond. >

Optimum semiconductors for high-power electronics

Abstract: Elemental and compound semiconductors, including wide-bandgap semiconductors, are critically examined for high-power electronic applications in terms of several parameters. On the basis of an analysis applicable to a wide range of semiconducting materials and by using the available measured physical parameters, it is shown that wide-bandgap semiconductors such as SiC and diamond could offer significant advantages compared to either silicon or group III-V compound semiconductors for these applications. The analysis uses peak electric field strength at avalanche breakdown as a critical material parameter for evaluating the quality of a semiconducting material for high-power electronics. Theoretical calculations show improvement by orders of magnitude in the on-resistance, twentyfold improvement in the maximum frequency of operation, and potential for successful operation at temperatures beyond 600 degrees C for diamond high-power devices. New figures of merit for power-handling capability that emphasize electrical and thermal conductivities of the material are derived and are applied to various semiconducting materials. It is shown that an improvement in power-handling capabilities of semiconductor devices by three orders of magnitude is feasible by replacing silicon with silicon carbide; improvement in power-handling capability by six orders of magnitude is projected for diamond-based devices. >

Power management and automation system

Abstract: An automation and energy management system includes an automation panel box (10) which may be positioned adjacent to a circuit breaker panel box (12) The automation panel box (10) includes one or more circuit breaker control modules (18), one or more device control modules (20, 64) and a power module (16) for providing power to the control modules (20, 64) The circuit breaker control module (18) provides signals to operate motorized circuit breakers (20), so as to turn on or off the power to a device being managed and the device control module (20) provides signals to control individual appliances A facility computer (72) generally communicates with the modules over a bus (52, 54) and issues commands to cause certain automatic functions or energy management to occur The signals on the status lines can override the facility computer signals and the actuation of one of the reset buttons (42) can override either the status signals or the facility controller (28)

Insulated gate bipolar transistor power module

Abstract: A power module contains IGBT die along with integrated circuit driver chips and opto isolators or isolation transformers within the same module housing. Output terminals are provided which can be interfaced directly to control logic or microprocessors for operating the module. The IGBTs may have current-sensing electrodes to simplify current measurement and control functions.

Lockable power module and method, particularly for electronic flash units

Abstract: A lockable power module is locked in position within a battery compartment of an electronic flash unit by manually displacing a pair of locking members on the module outwardly therefrom to tightly grip the compartment walls.

Apparatus for optical power transmission and optically powered system

Abstract: An apparatus for optical power transmission capable of reducing a number of photo cells and improving a power transmission efficiency, and an optically powered system using the apparatus capable of maximizing lifetime of light sources. The apparatus includes an alternating current transformer for transforming the electric power to a desired level for a load. The system further includes a device for detecting magnitude of the electric power, and a device for controlling an amount of light emission by the light source in accordance with the detected magnitude of the electric power such that the magnitude of the electric power to be given to the load is maintained to be substantially constant.

High performance, high current miniaturized low voltage power supply

Abstract: A high performance, high current, miniaturized low voltage power supply is disclosed which employs a thick copper-ceramic film primary board, a direct bonded copper secondary, flexible printed circuit power inductors, the power supply has high power leadless chip carriers, hybrid rectifier packages and various electrical circuits including application specific integrated circuits for control, a turn on protection and current sharing

System for supplying power

Abstract: A power supply is disclosed for both arc welding and plasma cutting. The power supply includes an A.C. power source, a transformer having a primary winding receiving power from the A.C. power source and secondary winding. Power in the secondary winding is rectified by rectifier to provide a first output suitable for arc welding and a second output suitable for plasma cutting. A switch connected to the rectifier selects between the two outputs. Conventional power supplies employ an inductance for stabilizing the current in the plasma cutting power supply. According to another aspect of the invention, the power supply includes a circuit path in parallel to the inductance for passing additional current to the torch so that the open circuit voltage applied to the inductance required for sustaining the arc is reduced.

Integration of ceramic capacitor

Abstract: A power module consisting of electronic components disposed within a hollowed-out, hermetically-sealed, multi-layered ceramic capacitor formed of spaced side walls of stacked alternating layers of conductors and dielectrics, the side walls being covered by top and bottom covers.

Solar dynamic power module design

Abstract: A design for a solar dynamic (SD) power module that meets all of the performance requirements for operating on orbit as a power source on the Space Station Freedom is presented. Assembly of the module in orbit will incorporate methods and procedures to be developed for other Freedom elements; no special equipment will be needed. The technology base for SD module development and production is shown to exist at both the system and component levels. The reasons are clearly indicated for adding SD power to Freedom; they include tremendous life-cycle cost savings, in conjunction with the advantage of having a hybrid or alternate power source in case some anomaly with PV occurs. >

Advanced solar Brayton space power systems

Abstract: The closed-Brayton-cycle space power system has been selected to supply electric power for the NASA space station and military space applications. These systems are based on well-proven superalloy metal technology that limits the turbine inlet temperature to the range of 1033 to 1144 K (1400 to 1600 degrees F). Significant performance improvements can be attained by increasing the turbine inlet temperature to the range of 1367 to 1644 K (2000 to 2500 degrees F). Development in ceramic and composite materials for gas turbines show promise for increasing the temperature of the closed Brayton cycle system to this range. These technologies and the improvements in solar-powered closed Brayton cycle power system performance that can be gained are discussed. >

Secondary electric power source produced by current flow through a primary a.c. power circuit

Abstract: Voltage drop developed across a transformer primary winding coupled in series with a primary a.c. power circuit including an a.c. power source and an a.c. load is utilized to provide a secondary source of a.c. power having secondary voltage level stability which is substantially independent from otherwise influential changes in primary power circuit levels. Secondary power stabilization is mainly established by constant voltage limiting of the primary winding excitation by the forward voltage drop developed across an arrangement of semiconductor junctions coupled in parallel with the primary winding. The transformer may be used to change the source level of the secondary a.c. power which is produced, and to obtain electrical isolation between the primary power circuit and any ancillary circuits coupled with the secondary a.c. power source.

Design of a high-performance floating power BJT driver with proportional base drive

Abstract: The computer-aided design of a high-performance driving circuit for a floating power BJT with proportional base drive is presented. The driver circuit power consumption is minimized and the power converter efficiency is maximized by optimizing driving and switching conditions of the power semiconductor switch. Simulation and experimental results are given. The driver circuit is ideally suited to be made in an integrated or hybrid form. >

A 500 Hz power system-applications

Abstract: Applications and needs of high-frequency power supplies in industrial zones, chemical and steel plants, and commercial areas are investigated. The applications of the higher frequency and the selection of the frequency are discussed in detail. The conclusion drawn is that the suitable frequency seems to range from 400 Hz to 1 kHz. Energy and space saving applications of the higher frequency to fluorescent lighting, amorphous metal core transformers, DC power supplies, and naturally commutated cycloconverters are experimentally demonstrated. In addition, it is shown that the conventional thyristor AC voltage controller can be used for a soft starter of very high-speed induction motors. >

Thermoemission reactor-converters for nuclear power units in outer space

Abstract: Thermoemission nuclear power units with built-in generators in the nuclear reactor core can be regarded as a promising source of electric power for supplying the needs of space equipment for various purposes with a wide range of electric power demands over a long service life and with acceptable mass-limit characteristics.

Space Station Freedom solar array design development

Abstract: The Space Station Freedom solar array program is required to provide a 75 kW power module that uses eight solar array (SA) wings over a four-year period in low Earth orbit (LEO). Each wing will be capable of providing 23.4 kW at the 4 yr design point. The design of flexible-substrate SAs that must survive exposure to the space environment, including atomic oxygen, for an operating life of fifteen years is discussed. The tradeoff study and development areas being investigated include solar cell module size, solar cell weld pads, panel stiffener frames, materials inherently resistant to atomic oxygen, and weight reduction design alternatives. >

Surface contact power connector

Abstract: A connector for a power module to selectively engage metallic pads positioned on the backplate printed circuit board is disclosed. The connector includes a first set of contacts and a second set of contacts positioned such that the first set of contacts makes engagement with the metallic pads before the second set of contacts make such engagement. The contacts are capable of carrying relatively high current.

Microwave oven with adaptable power module

Abstract: A microwave oven includes an oven cavity, into which HF power is fed from a microwave source, e.g. a magnetron energized by a power supply device. The power supply device with its components and the microwave source are cooled with the aid of a fan. The power supply device, the microwave source (12) and the fan (11) are combined into a so-called power module, which includes a substantially closed envelope (10) having an air inlet (15) and an air outlet (16), an input for the AC supply voltage and an output for HF power (30). The microwave source is mounted as a projecting part of the envelope at the air inlet or the air outlet of the power module. This makes it possible to adapt the power module to a great number of microwave oven constructions. The power module may be mounted at the top or bottom of the oven cavity or at the side of same. Feeding microwave energy into the oven cavity is possible both at the top and bottom thereof.

Engineering Design for Electrical Engineers

Abstract: I. PRINCIPLES. 1. Engineering Design. 2. Project Implementation. 3. Design Guidelines and Implementation. 4. Project Communication. II. PRACTICE. 5. Digital Module. 6. Analog Module. 7. Electromagnetics Module. 8. Feedback Control Module. 9. Communications Module. 10. Power Module.

High density surface mounting power supply

Abstract: The various stages in the design of a high-density surface-mounted power supply are described, including the development of the passive power components, power chip carrier package, and interconnection substrate. Emphasis is on the design and minimization of the power ceramic capacitor, quadrupole capacitor, and transformer components. The construction of a 16-60 V/5 V 20 A DC-DC converter using this technology has demonstrated that performance improvement and additional miniaturization requires the optimization of the pulse-width modulator of the power converter. >

Solar dynamic power for space station freedom

Abstract: The Space Station Freedom Program is presently planned to consist of two phases. At the completion of Phase 1, Freedom's manned base will consist of a transverse boom with attached manned modules and 75 kW of available electric power supplied by photovoltaic (PV) power sources. In Phase 2, electric power available to the manned base will be increased to 125 kW by the addition of two solar dynamic (SD) power modules, one at each end of the transverse boom. Power for manned base growth beyond Phase 2 will be supplied by additional SD modules. Studies show that SD power for the growth eras will result in life cycle cost savings of $3 to $4 billion when compared to PV-supplied power. In the SD power modules for Space Station Freedom, an offset parabolic concentrator collects and focuses solar energy into a heat receiver. To allow full power operation over the entire orbit, the receiver includes integral thermal energy storage by means of the heat of fusion of a salt mixture. Thermal energy is removed from the receiver and converted to electrical energy by a power conversion unit (PCU) which includes a closed brayton cycle (CBC) heat engine and an alternator. The receiver/PCU/radiator combination will be completely assembled and charged with gas and cooling fluid on Earth before launch to orbit. The concentrator subassemblies will be pre-aligned and stowed in the orbiter bay before launch. On orbit, the receiver/PCU/radiator assembly will be installed as a unit. The pre-aligned concentrator panels will then be latched together and the total concentrator attached to the receiver/PCU/radiator by the astronauts. After final electric connections are made and checkout is complete, the SD power module will be ready for operation.

A flexible control strategy to interface solar system with privileged load and utility line

Abstract: An intermediate photovoltaic power system (160 kVA, 380 V three-phase) that could be used as a stand-alone energy power supply and as an AC back up system has been designed. For this purpose it was necessary to use self-commuted inverters; a suitable power control logic was also required in order to compensate for reactive power and optimize power flow from the photovoltaic array to the AC power line. Good agreement between theoretical studies and simulation results confirms the validity of the proposed power control logic. >

Development of a DC-to-DC power converter

Abstract: A 2 in.*1 in.*0.18 in. planar transformer (consisting of two main transformers and four auxiliary transformers made of a low-profile magnetic structure and multilayer PWB windings) was fabricated and used in an interleaved flyback power converter. Power-train efficiencies greater than 80% were obtained at various input voltages, loads and temperatures using a 1 MHz, constant-frequency, pulse-width-modulated, zero-voltage resonant-transition switching technique. The highest efficiency observed was 85%. The results indicate that the planar transformer functions satisfactorily in an interleaved flyback power converter. However, power loss calculations result in 2 W unidentified losses when compared with the actual circuit performance. When discrete capacitors were replaced by a capacitor array substrate and the discrete MOSFET switches were replaced by MOSFET dies mounted on the capacitor substrate, the power conversion efficiency degraded 8%. This was attributed primarily to the extra lead resistance introduced by mounting the dies on the substrate. This loss could be reduced by improving the capacitor substrate metallization design. >

Space Power Free-Piston Stirling Engine Scaling Study

Abstract: The design feasibility study is documented of a single cylinder, free piston Stirling engine/linear alternator (FPSE/LA) power module generating 150 kW-electric (kW sub e), and the determination of the module's maximum feasible power level. The power module configuration was specified to be a single cylinder (single piston, single displacer) FPSE/LA, with tuning capacitors if required. The design requirements were as follows: (1) Maximum electrical power output; (2) Power module thermal efficiency equal to or greater than 20 percent at a specific mass of 5 to 8 kg/kW(sub e); (3) Heater wall temperature/cooler wall temperature = 1050 K/525 K; (4) Sodium heat-pipe heat transport system, pumped loop NaK (sodium-potassium eutectic mixture) rejection system; (5) Maximum power module vibration amplitude = 0.0038 cm; and (6) Design life = 7 years (60,000 hr). The results show that a single cylinder FPSE/LA is capable of meeting program goals and has attractive scaling attributes over the power range from 25 to 150 kW(sub e). Scaling beyond the 150 kW(sub e) power level, the power module efficiency falls and the power module specific mass reaches 10 kg/kW(sub e) at a power output of 500 kW(sub e). A discussion of scaling rules for the engine, alternator, and heat transport systems is presented, along with a detailed description of the conceptual design of a 150 kW(sub e) power module that meets the requirements. Included is a discussion of the design of a dynamic balance system. A parametric study of power module performance conducted over the power output range of 25 to 150 kW(sub e) for temperature ratios of 1.7, 2.0, 2.5, and 3.0 is presented and discussed. The results show that as the temperature ratio decreases, the efficiency falls and specific mass increases. At a temperature ratio of 1.7, the 150 kW(sub e) power module cannot satisfy both efficiency and specific mass goals. As the power level increases from 25 to 150 kW(sub e) at a fixed temperature ratio, power module efficiency is seen to increase slightly, but at the expense of increased specific mass. An empirical equation relating power module thermal efficiency as a function of power module specific mass, power output, and temperature ratio is developed. Alternative configurations to the single cylinder, direct coupled linear alternator approach are also evaluated, but are shown to have technical drawbacks that lessen their attractiveness. The dynamic balance assembly mass (moving mass and structure) represents 20 to 30 percent of the total single cylinder power module mass. Joining two modules in a balanced opposed configuration eliminates the need for the balancer, and a hot end junction can be made without significant addition of structural mass. Recommendations are made for evaluation of advanced heat pipe concepts, tests of radial flow heat exchangers, and evaluation of high temperature alternator materials.

A feasibility study of using thermoelectric converters for the LMFBR derivative ERATO-20 kWe space power system

Abstract: The results of a feasibility study of using thermoelectric (TE) converters, instead of the He-Xe turbo-alternator, in the ERATO/UO/sub 2//Na/SS space nuclear power system are presented. The results demonstrate that using either PbTe or SiGe TE converters would not only reduce the overall system mass and enhance the overall system reliability, but would also make full use of the terrestrial LMFBR technology in France. The TE-ERATO power system, when coupled to an oversized, 140 m/sup 2/ radiator, in addition to offering better integration with the Ariane 5 launcher, possesses a specific power in excess of 10 We/kg. >

A new series of smart controllers [for power convertors]

Abstract: A series of three intelligent power integrated modules for 0.4 to 1.5 kW AC-DC-AC inverted power conversion has been developed. Each of these is fabricated in one common and compact housing to produce a three-phase converter, a three-phase inverter using insulated-gate bipolar transistors, opto-couplers for input-to-output signal interfaces, and monolithic drive/protection logic. The internal architectures, functional and overall performance results, and the advantages of these smart controlling 'black boxes' are presented. >

Power control circuit for electronic equipment

Abstract: A power control circuit for electronic equipment including a power MOSFET the source-drain path of which is connected in series with the electronic equipment power supply, means for sensing the load voltage rise in the power supplied to the electronic equipment and feedback means responsive to the sensed voltage rise to control the gate voltage applied to the MOSFET over a predetermined period of time.

Electric controls for a high-performance EHA using an interior permanent magnet motor drive

Abstract: A controller for a high-performance electrohydrostatic actuator (EHA) has been developed using an interior permanent magnet (IPM) synchronous motor to produce the servo motion. The buried-magnet design of the IPM motor yields a combination of desired characteristics including high efficiency, robust rotor construction, and wide operating speed range. Power converter size has been minimized by using insulated-gate bipolar transistor (IGBT) power switches combined with high-voltage integrated circuit (HVIC) gate drivers in phase-leg power modules. Experimental results for the demonstrator motor-controller hardware rated at 12 hp (continuous) are presented which confirm the attractive performance characteristics of the IPM motor drive. >