By Topic

Industry Applications, IEEE Transactions on

Issue 3 • Date May-June 1991

Filter Results

Displaying Results 1 - 25 of 28
  • Discussion, with reply, of "Field experience with high-frequency ballasts

    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (53 KB)  

    The commenter formulates two questions for the author of the above-named paper (see ibid., vol.26, no.5, pp.810-11, 1990). The commenter points out that high-frequency ballasts typically use full-wave rectifiers to supply DC-AC inverters. He asks whether the author has found the power factor to be quite low and a significant harmonic content of the line current. He also asks whether these ballasts can be used with a DC power source. The author replies that; (1) high-frequency ballasts are commercially available with power factors in the range of 85-90%-the latest versions have less than 20% of third-harmonic content, and he has experienced no problems attributable to harmonic content during the course of installing over 70000 high-frequency ballasts at the University of California at Berkeley; and (2) DC sources can be used with high-frequency ballasts-however, it will probably prove necessary to modify either the existing DC source or the commercially available ballast in order to ensure compatibility.<> View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Circuitry in three dimensions: multifunctional molded plastic packages

    Page(s): 442 - 446
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (540 KB)  

    The topics dealt with are: some of the major structural/mechanical benefits of a molded circuit board; some of the material benefits of a molded circuit board; high-heat thermoplastics; resin materials for molded circuit interconnect fabrication; MCB metallization; MCB general properties; molded circuit interconnect applications; and the future of performance plastics and 3D molded circuit interconnects. Molded circuits consolidate circuitry, wiring and hardware into a one piece construction. The resultant integral assembly provides increased reliability and reduced costs. Elements of cost savings include reduced factory labor, parts consolidations, simplified product assembly, lighter weight, compact size, and unique function View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Experimental development of efficacious task source relationships in interior lighting applications

    Page(s): 448 - 454
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (676 KB)  

    Full-scale photometric simulation studies were conducted in order to examine the luminous environment within work-stations used in typical office environments. The objective of these experimental studies is to develop explicit geometric relationships between a visual task and a lighting layout that maintains visual quality and minimizes power required. Within these studies, a broad range of ceiling-integrated general and task lighting systems were examined in terms of their ability to maintain contrast and illuminance across the work plane. Within each lighting system studied, a range of furniture systems was used in order to determine potential obstruction effects as a function of orientation and position in respect to a particular lighting layout. Experimental data expressed in terms of luminance contrast and illuminance across the task plane show the importance of developing and specifying explicit geometric relationships between a visual task and a lighting system layout. The authors report on the ongoing experimental work and provide experimental data illustrating the variations in lighting quality as a function of geometry and task configuration View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Assignment of turn-on and turn-off power and energy losses in a GTO

    Page(s): 507 - 514
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (640 KB)  

    The authors discuss the turn-on and turn-off losses in a gate turn-off (GTO) thyristor which must be properly accounted for because they can comprise upwards of 60% of the total losses. The authors attempt to discuss and clarify the definitions of power loss and energy per pulse for the turn-on and turn-off intervals. It is shown that prior work defining turn-on and turn-off power and energy losses does not adequately include all losses associated with the turn-on and turn-off events. Thus, it will be difficult to account for all those losses determining the heating effects of the GTO unless improvements are made. An example shows that the error can be substantial (8 to 15%). For this reason, improved definitions that have an underestimation of only 1 to 2% of the switching losses have been proposed. It was also found that the gate losses during the turn-off event must be accounted for and that improved measuring techniques and instrumentation are both necessary and possible View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • New fixture applications for compact twin tube fluorescent lamps

    Page(s): 455 - 458
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (316 KB)  

    New and efficient luminaires have been designed for compact, twin tube-type fluorescent lamps. One important example of these new fixture applications is the 1×1 ft luminaire with three 18 W high lumen twin tube fluorescent lamps. Performance comparisons with this luminaire type have been made using different 18 W lamps operating on preheat and rapid start-type ballasts. The preheat (switch start) measurements were made at 240 V and 50 Hz using single lamp reactor type ballasts, and the rapid start measurements were made at 120 V and 60 Hz using three-lamp electromagnetic and electronic ballasts. In addition, comparisons are made against an older technology 150 W incandescent downlight fixture with approximately the same light output level indicating the substantial improvement in system photometric performance for these new compact fluorescent light sources View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Field-oriented asynchronous pulse-width modulation for high-performance AC machine drives operating at low switching frequency

    Page(s): 574 - 581
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (628 KB)  

    A novel pulse-width modulation (PWM) technique is based on the prediction of the trajectory patterns that the stator current vector describes in a field-oriented coordinate system. The method of field-oriented PWM control minimizes the switching frequency at given torque ripple. The harmonics of the field producing current are left to develop freely, permitting operation at values of switching frequency that are lower than those of the optimal schemes known so far. The optimal switching times are computed off line and are called from a memory during operation. Signal processing is performed in a simple hardware structure View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electro-mechanical analysis of the audible noise of an inverter-fed squirrel-cage induction motor

    Page(s): 539 - 544
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (580 KB)  

    The audible noise emitted by a three-phase squirrel cage induction motor fed by a frequency inverter is determined by the electromagnetic and mechanical behavior of the components of the drive. A computerized analysis method is described that uses theoretical and experimental data for predicting the audible noise spectrum components. Starting from the inverter voltage and the motor data, the electromagnetic forces are predicted and analyzed. The mechanical natural frequencies are considered, either in a theoretical (finite element calculation) or in an experimental (modal analysis) methodology, to predict the vibrational behavior of the machine. The scheme contains the following steps: analysis of the frequency spectrum of the inverter used; synthesis of the magnetic force spectrum accounting for the motor data: calculation or measurement of the resonant data of the stator assembly; and comparison of the force spectrum and the resonant data. These various steps are discussed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Operational results of OK series roller mill

    Page(s): 416 - 424
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (592 KB)  

    Operational results of a series roller mill, the OK36-4, which was installed at the Ofunato plant of ONODA Cement Co. Ltd. in 1988, are discussed. The maximum capacity and the specific power consumption are 137 t/h and 27.2 kWh/t, respectively, for ordinary cement grinding and 103.3 t/h and 32.8 kWh/t, respectively, for high early strength cement grinding. The quality of both ordinary and high early strength cement was the same as that from conventional tube mills. The mill has been operated stably without any problems due to vibration and wear up to the present. The scale-up policy for the OK mill was confirmed to be adequate to predict a capacity of the OK36-4 mill from that of the OK12-2 mill, which is the smallest among the series View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Fully digital, vector-controlled PWM VSI-fed AC drives with an inverter dead-time compensation strategy

    Page(s): 552 - 559
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (640 KB)  

    A dead-time compensation method in vector-controlled pulse width modulator (PWM) voltage source inverters (VSIs) is proposed. The method is based on a feedforward approach that produces compensating signals obtained from the Id-Iq current and inverter output angular frequency references in the rotating reference (d-q) frame. It provides excellent inverter output voltage distortion correction for both fundamental and harmonic components. The correction is not affected by the magnitude of the inverter output voltage or current distortions. Since this dead-time compensation method allows current loop calculations in the d- q frame at a slower sampling rate, with a conventional microprocessor than calculations in the stationary reference frame, a fully digital. vector-controlled speed regulator with just a component current control loop is realized for PWM VSIs. Simulations and test results obtained for the compensation method are also described View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis and design of a series-parallel resonant converter with capacitive output filter

    Page(s): 523 - 530
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (540 KB)  

    The objectives are to propose a LCC-type parallel resonant power converter with a capacitive output filter, to present its different operating modes and analyze the converter for these modes, to obtain design curves based on the analysis to present a simple design procedure for the proposed converter, and, finally to provide experimental results. A high-frequency link series-parallel resonant power converter with capacitive output filter is proposed and analyzed using the state-space approach. Analysis shows that the converter enters into three different modes. The normalized load current and other component stresses are plotted against the converter gain. Detailed experimental results are presented to verify the theory View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Phase-resolved thermal modeling of a fluorescent lamp electrode as a function of current waveshape and frequency

    Page(s): 459 - 470
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (848 KB)  

    A modeling technique for calculations of approximate phase resolved temperature profiles of a fluorescent lamp electrode is presented. Analytical expressions for instantaneous electrode temperature are derived by solving a set of simplified differential equations describing time domain electrode temperature dynamics. The electrode surface temperature fluctuations are a function of current waveshape and its operating frequency. The model shows that moderate temperature fluctuations may indicate the safe operating conditions as far as lamp life expectancy is concerned View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • ESD characteristics of a generalized two body system including a ground plane

    Page(s): 471 - 479
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (692 KB)  

    Capacitance coefficients were measured for a system with two conductors of variable size, positioned at different elevations with respect to a horizontal ground plane. For a constant charge on the source, body potentials and energies were calculated, and a comparison was made of the relative probability of a discharge and the severity of the discharge for the various source/sink geometries. Both a fixed-size source model and a fixed-size sink model were analyzed for cases where the sink was floating or grounded. For the case where both bodies are floating, both the relative probability of discharge and the severity of the discharge decrease if the size of the source is increased relative to the size of a fixed sink or the size of the sink is decreased relative to the size of a fixed source. For a system in which the sink is grounded, both the relative probability of a discharge and the severity of a discharge decrease if the size of the source is increased relative to the size of the fixed sink and increase if the size of the sink is decreased relative to the size of a fixed source. Positioning the bodies close to a horizontal ground plane decreases both the probability of a discharge and the severity of the discharge. Potential and energy sensitivity factors were calculated and used to show how the observed results can be interpreted using the changes in the capacitance coefficients of the system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Steady-state analysis and design optimization of an inductor-transformer resonant DC-DC converter

    Page(s): 515 - 522
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (568 KB)  

    The authors present a closed-form steady-state analysis of an inductor transformer resonant DC-DC power converter. This efficient method of analysis, which directly predicts the steady-state characteristics of the circuit, is used to develop an optimal design methodology. Normalized optimum design tables and curves are derived. The optimization procedure is summarized and is illustrated by a design example. State plane analysis is used to show the important role of the circuit leakage inductances on the steady-state performance of the system. Experimental results obtained from a prototype converter are used to verify the analytical results View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Contribution to the discussion of `1987 ampacity tables-demystifying the myths'

    Page(s): 440 - 441
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (140 KB)  

    The author discusses J. Nasilowski's remarks (see ibid., vol.26, no.4, p.605, 1990) on a paper by D.W. Zipse (see ibid., vol.25, no.5, pp.910-17, 1989). Nasilowski claimed that in M=(hS/R)1/2, where M is the current coefficient of heating, h is the heat transfer coefficient, including both convection and radiation, S is the surface area of the conductor, and R is the resistance, M is constant for a specific material for a range of currents and for temperature rises up to about 60 K. The author argues that M is approximately constant only for a specific conductor and for restricted ranges of temperature rise and ambient temperature. In his reply, Nasilowski stresses the utility of the assumption that M =constant for calculations of steady state temperature rise of the conductors in a quiet air View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A new simultaneous gating GTO dual converter-fed DC motor drive without circulating current

    Page(s): 560 - 566
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (960 KB)  

    A new dual power converter, comprised of two three-phase AC-DC pulse width modulated (PWM) gate turn-off thyristor (GTO) converters, is proposed. The gating pulse pattern of the converters is chosen such that no circulating current flows between the converters when they are operated simultaneously. In addition, a good input power factor is obtained with less ripple in the output current. A symmetrical type of gating is worked out in which all the GTOs in the converter are switched an equal number of times during each cycle of the source voltage. The motor current is free to reverse naturally at any moment, and hence, the possibility of discontinuous conduction of the motor current does not arise. A four quadrant, closed loop, speed controlled DC motor drive fed from the proposed dual converter is designed, constructed, and tested. The experimental results obtained are shown to be in good agreement with theory View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Performance of a 10-Hp switched reluctance motor and comparison with induction motors

    Page(s): 531 - 538
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (584 KB)  

    A comparison of computed and measured performances of a 10 hp Oulton switched reluctance motor (SRM) and a comparison with the performance of induction motors are presented. The instantaneous current and torque waveforms are computed for the SRM using the results of finite element method (FEM) analysis. The SRM calculated and experimental locked rotor torque, instantaneous current, efficiency, and losses when pulsed voltage excitation is applied to the motor windings were compared. In all cases, there is quite good agreement between the theoretical and experimental results. In addition, the measured total losses, efficiency, and temperature rise for a 10 hp SRM and different induction motors of the same rating are presented. The SRM has a higher efficiency and a lower temperature rise than the induction motors tested View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Life extension for electrical power distribution systems using vacuum technology

    Page(s): 406 - 415
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1452 KB)  

    Three alternatives for upgrading old equipment are discussed. Retrofitting with vacuum arc interrupter technology is the most cost effective and offers many advantages over older air-magnetic interrupters. These include simpler design, fewer parts and less maintenance, readily available parts, high reliability, extended insulation life and safety. The authors address modernization options available to industry specifically in the area of electrical switchgear. Emphasis is given to switchgear life extension using vacuum technology, its benefits, reliability, and economic justification. Several examples and applications are presented View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Variable-speed control of brushless half-speed synchronous motor by voltage source inverter

    Page(s): 545 - 551
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (528 KB)  

    The variable-speed control of a voltage source inverter-fed cylindrical rotor type of brushless half-speed synchronous motor with feedback of the rotor position is described. On the basis of an approximate analysis of the steady state, an expression for torque is derived, and two methods of speed control are discussed. The step response of speed in the drive system is almost the same as that in a speed control method based on a slip frequency control in an induction motor drive, and a relatively high torque is obtained even in a low speed region. The motor has the capability of line start and change over from an induction motor (Gorges phenomenon) to a self-controlled half-speed synchronous motor by using a simple position sensor View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A new nonlevitated mode of traveling wave toner transport

    Page(s): 480 - 487
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (744 KB)  

    A new mode of transporting charged particles with traveling electrostatic waves is described; it is distinguishable from the curtain mode of S. Masuda (1971,OP1972) and the hopping mode of J.R. Melcher et al. (1989). Structures specifically designed to produce running waves of sufficient strength to move typical xerographic toner synchronously and in sliding contact along a surface without altering their charge are described. Experimental results that strongly indicate that the desired synchronous motion is achieved are presented, but the toner appears to move as tiny clouds rather than in sliding contact with the transport structure. The transport thus appears akin to the synchronous hopping mode of Melcher. However, evidence is presented that indicates the cloud-like character is due to surface scattering rather than lift by the wave, as in the case of hopping. Measurements of mass transport rate that characterize the present mode of transport are presented along with representative development characteristics that illustrate the potential of traveling wave transport as a sensitive scavengeless development process View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A current source PWM inverter with instantaneous current control capability

    Page(s): 582 - 588
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (524 KB)  

    A new approach for the control of a current source pulse width modulated (PWM) inverter is proposed to achieve instantaneous current control capability. The proposed scheme provides instantaneous current response in the AC motor by altering the modulation index of the current source PWM patterns. In order to achieve this task, optimum programmed PWM patterns with selective elimination of lower order harmonics in the motor line currents are used. Output filter capacitors are provided to bypass the current harmonics in the inverter output and allow for the instantaneous changes in the line currents. This method of control provides sinusoidal output voltages and sinusoidal currents in the AC motor. The proposed scheme guarantees fast response characteristics combined with high-performance steady-state behavior. A design procedure for the current source PWM and selection of programmed PWM current patterns for a variable-speed situation is illustrated. Selected results are verified experimentally View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An overview of the formation of SOx and NOx in various pyroprocessing systems

    Page(s): 431 - 439
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (756 KB)  

    The regulations on SO2 and NOx emission from cement plants in the US are briefly described and compared with European regulations. The authors try to identify the SO2 and NOx emission levels of various kiln systems and explain the reasons for the variations ascertained. Various recent methods of reducing SO 2 and NOx emission from cement kiln systems are outlined. Due to the less intensive contact between gas and material in conventional wet and long dry kilns and their high specific heat consumption, on an average basis, specific SO2 emission from these types of kilns is 4-8 times higher than that from efficient suspension preheater and precalciner kiln systems. Even preheater and precalciner kilns may have high SO2 emission levels based on future standards if the raw materials contain considerable amounts of sulfides that will oxidize to SO2 that is already in the upper preheater stages. Moreover, SO2 may be let out into the atmosphere from large kiln gas bypass systems (in precalciner kiln systems). In such systems, it may be necessary to add burnt lime or calcium hydroxide to the upper preheater stages or the conditioning tower to reduce SO2 emission. The difference in NOx emission levels between various kiln systems is less pronounced. Use of kiln control systems, the new generation of LOWNOX kiln burners, and staged combustion in the secondary firing region may reduce the average NOx emission from SP and precalciner kilns by up to 50% View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Production of thin, uniform toner layers through use of a contact blade with mono-component development systems

    Page(s): 495 - 500
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (560 KB)  

    The authors focus on the effects of contaminants on the uniformity of the toner layers resulting from the direct observation of the toner flow and metering phenomena. The authors have improved earlier observation methods to observe directly and analyze the toner transportation and toner behavior in the layer thickness control area. Using the improved method, they have experimented with the various kinds of toner transportations and layer thickness control systems. They concentrated on disruption of toner layers by contaminant infiltration and found that static toner and friction force against the toner on the developing sleeve are most important in preventing a contaminant from entering the metering area. Based on these results, they found a highly stable layer-forming method, called the contact blade method. which minimizes the effects of infiltration by contaminants View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cement plant preheater fan build-up control

    Page(s): 425 - 430
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (680 KB)  

    Material buildup on preheater fans is a significant problem worldwide. The authors describe two approaches to study this problem: (a) a survey of experiences from several cement plants around the world; and (b) a laboratory study to research the problem under controlled conditions. Both approaches have revealed significant insights to this problem from which recommendations are made to minimize the problem. The buildup problem is definitely temperature and impact velocity related. This supports the theories involving lower melting point alkalines forming a sticky compound that then catches other solid particulates and forms the buildup. It would appear that sulfur is ruled out as a cause of this buildup (there is no sulfur in the fuel in the lab test, but buildup still occurs). Formation of FeCl3 as a result of chlorine reacting with the steel in the rotor can also be ruled out as the buildup still occurred, even with stainless steel and other protective (noniron) coatings on the rotor View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Energy management for rational electricity use-reducing cost and consumption at SECIL's Outao cement plant/Portugal

    Page(s): 398 - 405
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (588 KB)  

    Compania Geral de Cal e Cimento SARL (SECIL) is in the process of implementing a comprehensive and modern energy management project for rational use of electricity. A step in energy management implementation is the reduction of electric energy consumption (kWh/t). The preparation and first results of this new effort is the major topic. Emphasis is placed on extensive electronic energy metering and process data recording. These data are processed and refined to energy information that, in effect, uncovers hidden savings potentials. Energy information and related saving measures are introduced into daily organizational operating procedures and are backed up by a permanent energy management team. More than a 6% per annum electric energy cost reduction has already been achieved. Additionally, a 3 to 6% reduction of specific electric energy is a projected savings objective View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Circuit utilization characteristics of MOS-controlled thyristors

    Page(s): 589 - 597
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1032 KB)  

    The purpose of this paper is to provide an insight into the present state of MOS-controlled thyristor (MCT) development as reflected in measured device terminal characteristics. User-oriented information regarding MCT circuit utilization is presented by focusing on the measured characteristics of a particular batch of MCTs (80 A, 500 V) fabricated in 1988. Measurements confirm the appealingly low forward voltage drop of the MCTs (1.1 V at 200 A/cm2, 1500°C). To increase current handling capabilities, eight matched devices have been paralleled to switch 600 A at 275 V (peak), representing a modest 6% device current derating. Measured MCT turn on is faster than turn off, which is dominated by internal charge recombination characteristics. Safe operating area and di/dt limits of the tested MCTs are discussed. Comparison with insulated-gate bipolar transistors (IGBTs) indicates that MCTs offer clear advantages for minimizing on-state conduction losses (approximately 3:1 at 150°C), whereas switching times of new MCTs are as low as those of comparable IGBTs View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

The scope of the IEEE TRANSACTIONS ON INDUSTRY APPLICATIONS includes all scope items of the IEEE Industry Applications Society, that is, the advancement of the theory and practice of electrical and electronic engineering in the development, design, manufacture, and application of electrical systems, apparatus, devices, and controls to the processes and equipment of industry and commerce; the promotion of safe, reliable, and economic installations; industry leadership in energy conservation and environmental, health, and safety issues; the creation of voluntary engineering standards and recommended practices; and the professional development of its membership.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Carlton E. Speck