By Topic

Industry Applications, IEEE Transactions on

Issue 2 • Date Mar/Apr 1993

Filter Results

Displaying Results 1 - 25 of 30
  • Effect of waveform distortion on protective relays

    Page(s): 404 - 411
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (660 KB)  

    The influence of harmonics on protective relays is described theoretically, and the results of laboratory tests are given. Representative relays using various operating principles were tested using fundamental currents and/or voltages, single-frequency inputs that were multiples of the fundamental frequency, realistic combinations of fundamental and harmonics. From the theoretical concepts and expectations discussed and the test results, it is shown that the influence of mixed-frequency harmonics (with magnitude decreasing with order) on the steady-state behavior of the protective relays studied is insignificant. Pure single-frequency inputs, above the fundamental, caused a distinct change in relay operations View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Balancing device stresses by fundamental cancellation

    Page(s): 369 - 374
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (344 KB)  

    The technique of harmonic cancellation relies on destructive interference of specific Fourier components between two or more similar but phase-displaced waveforms. The components eliminated are traditionally harmonics of the basic operating frequency. However, there is a no inherent reason why the fundamental cannot be eliminated. The intuitively repellent concept can be advantageously employed to balance device (current fed converter) stresses in single-phase applications. A typical application is examined by simulation to illustrate that traditional methods can result in unbalanced conditions. A method is described for deriving suitable waveforms for fundamental elimination. The simulation is repeated with the selected waveforms to show that balance has been restored View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Real-time issues of transputers in high-performance motion control systems

    Page(s): 306 - 312
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (652 KB)  

    The real-time issues related to using transputers to implement high-performance AC motor drive controllers because of their direct support for parallel processing are addressed. They include event response time, scheduling strategies, I/O, and real-time kernel performance. The implementation of part of a real-time kernal consisting of a multiple event handler and an efficient scheduler, to improve the transputer's real-time performance, is described. In addition to supporting high-performance controller tasks, the real-time kernel implements features such as parameter sampling and user interaction. The kernel is intended to be a platform to support a highly programmable and configurable controller suitable for a wide range of motion control applications. Test results are presented to show the performance of the kernel View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Numerical modeling for potential relaxation of charged oil in containers

    Page(s): 295 - 299
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (448 KB)  

    A numerical model that simulates the relaxation process for surface potential at the surface of a charged oil in a grounded metal vessel is developed. In the model, constant (ohmic) conductivity of the oil is assumed, and a surface conduction mechanism for the dissipation of electric surface charge is introduced. Calculations for a cylindrical vessel of diameter Dt, height Ht, and fill fraction F show that the charge relaxation is influenced by vessel geometry and fill level, as expected, and by the absolute size of the vessel as well. In fact, it is found that the effective relaxation time of the surface potential correlates quite well to a dimensionless quantity Dtκ/λ, where κ (in Siemens per meter) is the bulk conductivity of the oil, and λ (in Siemens) is the effective surface conductivity at the oil/air interface View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • On the dielectrophoretic separation of solid particles

    Page(s): 268 - 273
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (436 KB)  

    An analysis of an idealized high-gradient dielectrophoretic separator that is simply a metal circular filament placed in a uniform electric field between two parallel plates is presented. The analysis is aimed at determining the spatial distribution of the electric field inside the volume of the separator, so that the dielectrophoretic force on a dielectric particle can be evaluated. The conditions necessary for producing dielectrophoretic forces comparable to those in electrostatic separators are determined View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design considerations for high-frequency coaxial winding power transformers

    Page(s): 375 - 381
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (636 KB)  

    The use of coaxial windings to create low-loss, low-leakage-reactance, power transformers for use in high-frequency soft-switched DC/DC and resonant converters has been demonstrated by M.H. Kheraluwalest al. (1990). Some of the important loss aspects of the design of coaxial winding transformers are examined, including the influence of the skin effect on winding resistance, the variation of core loss caused by nonuniform core flux density, and the choice of the principle dimensions and aspect ratios for maximum efficiency. Experimental measurements on a 50 kVA, 50 kHz unit are included to confirm portions of the analytical results and suggested design procedures View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Understanding and measuring iridescence (spectral banding) of anodized luminaire surfaces

    Page(s): 256 - 261
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (472 KB)  

    Iridescence is a problem of increasing concern since the introduction of narrowband lamps and anodized luminaire surfaces. It appears as induced coloration of luminaire surfaces, much like rainbow patterns associated with thin oil or soap films on water. The causes of the effect are discussed, and an interim color measurement method based on standard CIE (1986) and ASTM (1987) practices for the measurement of color in terms of the human visual system is proposed. An analysis of the nature of the effect is provided so that the problem at hand can be better managed and understood View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Applying power electronics to residential HVAC-the issues

    Page(s): 300 - 305
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (548 KB)  

    Several of the market and application issues bearing on the economics of residential variable speed air conditioners and heat pumps are outlined. Technical details of capacity modulated systems are avoided, along with design issues involving power semiconductors, motor torque and speed control strategies, and integration in silicon for these applications. The author intends to provoke the development of creative improvements in the economics and application of variable speed electronics technology. He identifies the more important issues to aid the development of marketing strategies that will exploit the potential of air conditioning products containing power electronics, enabling them to penetrate the heating, ventilation, and air conditioning (HVAC) market and compete successfully against conventional systems View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Quasi-dual modulation of three-phase PWM converters

    Page(s): 313 - 319
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (508 KB)  

    The possibility of transferring the modulation method developed for a pulse width modulated (PWM) power converter with a DC voltage link (VLC) to a PWM converter with a DC current link (CLC) based on the inverse current and voltage behavior of these two systems is evaluated. The duality between VLC and CLC, which has been intuitively clear, is treated here in a scientific approach. It is shown that the nonplanar property of three-phase bridge circuits leads to a quasi-dual relation of the switching states of the VLC and CLC systems. The code conversion of the binary switching functions of a VLC into control signals of the power electronic devices of a CLC is given. The remaining degree of freedom of the correspondence is set by the requirement of minimum switching frequency of the converter View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Shaft voltages and rotating machinery

    Page(s): 419 - 426
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1024 KB)  

    In order to determine whether a machine is experiencing shaft voltage and current problems, recognition of the four types of damage is imperative. The four distinct types of shaft current damage, frosting, spark tracks, pitting, and welding are described. The four shaft voltage sources and their means of generation are discussed in detail. Methods for correction and/or elimination of these sources are reviewed, so that users can better understand how these voltages and currents are generated. Tests for the detection of shaft voltage sources and their potential circuits are outlined. The most promising, by far, in terms of identifying the potential voltage source, is the direct measurement of shaft voltage and currents. It appears that even though certain assumptions are necessary in this method of testing and analysis, when these measurements are combined with an adequate background of electrical theory, they are extremely useful in determining the health of the train with regards to circulating currents View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Control of high-performance interior permanent magnet synchronous drives

    Page(s): 328 - 337
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (752 KB)  

    Control strategies for an interior permanent magnet (IPM) machine suitable for field weakening are considered. Different control approaches that identify a robust and fast torque control scheme are investigated. A flux-oriented frame based on a flux observer is chosen. An allowable operating area in the state plane is selected, and the related boundaries are implemented in the control scheme. Simulated behavior is given, together with the experimental behavior obtained with a prototype drive View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Testing of large motors to API 542 and 546 standards

    Page(s): 427 - 435
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1028 KB)  

    The API 541 and 546 standards address the design, testing, and performance of AC induction motors larger than 250 HP and AC synchronous motors larger than 500 HP. A summary of requirements for testing large AC motors to these specifications as well as an overview of the testing facilities and methods necessary to address these requirements are provided. Testing of special-purpose motors requiring more stringent tests is specifically addressed. The additional test requirements specified by the API standards, especially with regard to balance and vibration, are examined. In order to satisfactorily test large machines to the present and forecast needs of the petroleum industry, a test facility with a capacity of approximately 50 MVA is assumed View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Resonant snubbers with auxiliary switches

    Page(s): 355 - 362
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (596 KB)  

    A resonant snubber is described for voltage-source inverters, current-source inverters, and self-commutated frequency changers. The main self-turnoff devices have shunt capacitors directly across them. A temporary parallel path through a small ordinary thyristor and inductance takes over high-stress turn-on duty from the main device in a manner that leaves no energy trapped after switching View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • An integrated grounding practice for digital systems

    Page(s): 459 - 467
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (836 KB)  

    The problems encountered in the design of grounding systems for digital systems to meet both the requirements of the National Electrical Code (NEC) and the equipment manufacturer's site planning manuals and installation instructions are discussed. The authors point out the NEC requirements and the inconsistencies between the NEC and the manufacturer's requirements. An integrated grounding practice which can be followed by the equipment manufacturers, engineering and construction companies, and process and manufacturing companies is described View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effect of moisture on the dielectrophoretic spectra of glass spheres

    Page(s): 281 - 285
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (440 KB)  

    Variable-frequency measurements (from 10 to 105 Hz) on individual glass particles (~50 μm diameter) were performed, using an automated computer-controlled dielectrophoretic levitator. The particles were suspended in silicone oil after either of two treatments: long-term exposure to a water-saturated atmosphere, or drying in a low temperature oven (~250°C). The moisture treatment caused in increase of several orders of magnitude in the Maxwell-Wagner polarization relaxation frequency. Heat drying was observed to decrease any Maxwell-Wagner relaxation below the 10 Hz limit of the levitator. Uncertainties about the interrelationship of surface adsorption of water by the glass particles and the dissolved water content of the silicone oil exist, but it seems that the relaxation frequency shifts are due to changes in water concentration at the glass/water interface. The measurement capability demonstrated has implications with respect to the controversy surrounding the influence of moisture content on the performance of electrorheological fluids View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • DSP-based speed adaptive flux observer of induction motor

    Page(s): 344 - 348
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (348 KB)  

    A method for estimating the rotor flux and speed of an induction motor based on adaptive control theory is presented. The method is applied to a direct field-oriented induction motor control without speed sensors. The influence of the parameter variation on the speed estimation can be removed by the proposed parameter adaptive scheme. The validity of the adaptive flux observer is verified experimentally View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Health effects of extremely low-frequency (50 and 60 Hz) electric and magnetic fields

    Page(s): 447 - 458
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1180 KB)  

    The author provides assistance to the scientific and technical community in putting the subject into perspective while the furor in the media over health effects of low-frequency fields abates. The voltages and currents generated within the human body are detailed. The values of directly applied voltages and currents that occur when a person comes into contact with energized conductors, which are hazardous to humans, are compared with the nonhazardous induced voltages and currents. An overview of the animal, cell, and human research and the epidemiological studies is presented. The positions taken by the various concerned groups are indicated. The existing standards and values that have been developed by consensus groups are presented. Continuation of research is advocated View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Dynamic equalization during charging of serial energy storage elements

    Page(s): 363 - 368
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (488 KB)  

    A technique is described that equalizes the amount of charge in a serial string of energy-storage cells during charging by using DC-to-DC converters to divert portions of the charging current past selected cells (or groups of cells). When no converters are operating, the charging current through the string is equal to that of the charging source. As the string charges, one cell eventually reaches a threshold voltage VA. At threshold, a shunt converter is activated to divert current around the cell, thus maintaining it at VA. The diverted current extracts energy, which is returned to the charging bus and appears as an additional charging current to the source. This positive feedback increases the current available for charging the string and allows the least charged cells, or cells of larger capacity, to be charged at higher rates than available directly from the source. During discharging, the converters across the remaining cells supply energy to the bus, while the converter across the open cell maintains a constant terminal voltage. The maximum current gain of the system is equal to the number of converters used in the system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Single-ended soft-switching electronic ballast with unity power factor

    Page(s): 382 - 388
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (472 KB)  

    A soft-switching single-ended AC/AC converter that is suitable for a high-frequency electronic lamp ballast is described. In spite of its simplicity, the converter offers excellent performance with regard to load and supply, ensuring high-frequency supply to the lamp, sinusoidal and in-phase supply current, easy control of lamp power, and high efficiency due to soft switching at both turn-on and turn-off. Steady-state operation, control characteristics, and design criteria are discussed, and experimental results for input and output circuit performance, component stress, and efficiency are reported View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Effect of voltage waveform on partial discharge in ferroelectric pellet layer for gas cleaning

    Page(s): 262 - 267
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (556 KB)  

    The effect of voltage waveform and frequency on a partial discharge in a ferroelectric pellet layer is experimentally studied. A description of the experimental apparatus is given. The capacitance of the pellet layer, the effect of frequency of the voltage on the partial discharge, and the effect of the dielectric constant (∈s) value of the pellet on the partial discharge are discussed. A partial discharge with square wave voltage, the power of the partial discharge, the removal of ammonia, and removal of NOx are described View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Microprocessor-based arc voltage control for gas tungsten arc welding using gain scheduling

    Page(s): 250 - 255
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (516 KB)  

    Limitations of the traditional automatic voltage controller (AVC) for gas tungsten arc welding are explained, and the characteristics of the welding arc that cause these limitations are presented. The design of an adaptive AVC using a microprocessor-based controller is described. The enhanced AVC uses gain scheduling to maintain optimum gain in the feedforward loop of the system and offers a constant arc length control mode that is extremely useful under conditions where the welding current is varied over a wide range. Both of these features are implemented with the use of look-up tables that define the correct parameters for the current operating point. The construction of these look-up tables must be offline in the design phase. A prototype system has been constructed and tested. It has proved to provide a full control of the arc length during weld pass termination, and experiments have shown that tail-out cracking in alloys prone to these kinds of defects, like Inconel 718, can be reduced by controlling the heat input during this process View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • The semiconductor junction igniter: a novel RF and ESD insensitive electro-explosive device

    Page(s): 412 - 418
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (576 KB)  

    The description and characterization of a monolithic, solid-state electroexplosive device are presented. The structure is inherently immune to radio frequency (RF) radiation and also offers protection from electrostatic discharge (ESD). Interconnection to the device can be accomplished by a variety of techniques, such as soldering, epoxy, etc. Standard microelectronic techniques were utilized for fabrication. The devices can be manufactured very economically and in large quantities View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Voltage sags in industrial systems

    Page(s): 397 - 403
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (560 KB)  

    The cause of voltage sags in industrial plants, their impacts on equipment operation, and possible solutions are described. The definition proposed focuses on system faults as the major cause of voltage sags. The sensitivity of different types of industrial equipment, including adjustable speed drive controls, programmable logic controllers, and motor contactors is analyzed. Available methods of power conditioning for this sensitive equipment 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 low-cost converter for switched reluctance motor drives

    Page(s): 320 - 327
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (552 KB)  

    The analysis and design of a low cost, one-switch-per-phase power converter topology suitable for low performance switched reluctance motor (SRM) applications are described. The converter has the advantage of using a minimum possible number of semiconductor devices in the power circuit without the attendant need for a bifilar winding, so that its drive requirements are minimal and the windings are simple. This is achieved by eliminating the additional semiconductor switch(es) normally required for regeneration. Energy stored in the phase windings during conduction time is partially dissipated in a resistor, whereas the rest is converted to mechanical power. A complete steady-state analysis of the drive including the input filter parameters is given. Closed-form expressions for determining the current and voltage stresses on the semiconductor devices are derived, and they are cast in normalized form for use in selecting the ratings of the power devices. Experimental verification of the key results is provided for a 6/4-pole SRM drive system View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Servo drive system and control characteristics of salient pole permanent magnet synchronous motor

    Page(s): 338 - 343
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (476 KB)  

    Permanent magnet (PM) synchronous motors fed by PWM inverters are considered. PM motors sometimes have a saliency, in which the q-axis inductance is larger than the d-axis inductance. A high-performance servomotor drive system for a salient-pole PM motor is described. An armature current vector is actively controlled according to load conditions in order to use a reluctance torque effectively, and, as a result, a large torque can be produced. The control algorithm for the armature current vector is described, taking the demagnetization of the PM and the magnetic saturation into account. Characteristics such as torque, power factor, efficiency, power capability, transient responses, etc. are examined in detail by computer simulations and experimentally 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