By Topic

Industry Applications, IEEE Transactions on

Issue 5 • Date Sept.-Oct. 2004

Filter Results

Displaying Results 1 - 25 of 40
  • Table of contents

    Page(s): c1 - 1173
    Save to Project icon | Request Permissions | PDF file iconPDF (51 KB)  
    Freely Available from IEEE
  • IEEE Transactions on Industry Applications publication information

    Page(s): c2
    Save to Project icon | Request Permissions | PDF file iconPDF (47 KB)  
    Freely Available from IEEE
  • Current practices and customer value-based distribution system reliability planning

    Page(s): 1174 - 1182
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (336 KB) |  | HTML iconHTML  

    Among the major issues facing utilities in today's competitive electricity market is the pressure to hold the line on rates and provide electricity with adequate quality and reliability. Utilities are increasingly recognizing that the level of supply reliability planned and designed into a system has to evolve away from levels determined basically on a technical framework using deterministic criteria, and toward a balance between minimizing costs and achieving a sustainable level of customer complaints. Assessment of the cost of maintaining a certain level of supply reliability or making incremental changes therein must include not only the utility's cost of providing such reliability and the potential revenue losses during outages, but also the interruption costs incurred by the affected customers during utility power outages. Such a cost-benefit analysis constitutes the focal point of the value-based reliability planning. Value-based reliability planning provides a rational and consistent framework for answering the fundamental economic question of how much reliability is adequate from the customer perspective and where a utility should spend its reliability dollars to optimize efficiency and satisfy customers' electricity requirements at the lowest cost. Costs to customers associated with varying levels of service reliability are significant factors that cannot be ignored. Explicit considerations of these customer interruption costs in developing supply reliability targets and in evaluating alternate proposals for network upgrade, maintenance, and system design must, therefore, be included in system planning and design process. The paper provides a brief overview of current deterministic planning practices in utility distribution system planning, and introduces a probabilistic customer value-based approach to alternate feed requirements planning for overhead distribution networks. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Distribution load flow methods for shipboard power systems

    Page(s): 1183 - 1190
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (376 KB) |  | HTML iconHTML  

    With the recent initiatives to modernize large ship power systems, ship builders are integrating technologies with the aim of an all-electric energy system. New control strategies utilizing distribution automation and network reconfiguration provide greater flexibility, reliability, and quality of service. These automated controls require efficient and accurate load flow solutions. A critique of classical and distribution power-flow methods is conducted for shipboard distribution automation. Three classical radial-network power-flow methods are reviewed. A modification of the forward-backward sweep method is presented, which enhances the computation time and solution convergence. Comparative tests are conducted on a new benchmark test system of a ship's distribution network. The results demonstrate that the modified forward-backward sweep method succeeds in being the fastest method with good convergence on networks with low X/R ratios. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Emergency generator startup study of a hydro turbine unit for a nuclear generation facility

    Page(s): 1191 - 1199
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1080 KB) |  | HTML iconHTML  

    This paper reports the implementation of synchronous generator, induction machine, hydro turbine, and governor system, and excitation and automatic voltage regulator system models for transient stability study. These models are frequency dependent and are suitable for system transient studies involving drastic frequency changes, including generator startup and emergency load startup. A computer simulation program has been developed using these models for a transient stability study. The developed program is further validated and verified using real system testing data that includes the cases of generator startup and full-load shed in a nuclear power generation plant. Validation results show overall an excellent correlation between the computer simulation and the field-testing data. As a result, the program has been accepted by the plant for system modeling and emergency generator startup simulation studies. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Application of material characterization techniques to electrical forensic analysis

    Page(s): 1200 - 1204
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2240 KB) |  | HTML iconHTML  

    The application of forensic science techniques to electrical equipment failure investigation has not been widely documented in the engineering world. This paper is intended to share an example of using material characterization techniques to support an initial cause determination of an electrical component "failure" event. The resulting conclusion supported the initial cause determination and ruled out the possibility of design deficiencies. Thus, the qualification testing of the equipment was allowed to continue to successful completion. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Experimental study of the detachment and the reattachment of an airflow along an inclined wall controlled by a surface corona discharge-application to a plane turbulent mixing layer

    Page(s): 1205 - 1214
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (744 KB) |  | HTML iconHTML  

    This paper analyzes experimentally the ability of an electrohydrodynamic actuator to modify the properties of a plane turbulent mixing layer in the wake region of an inclined flat plate (expansion corner). The experiments consists of applying a surface corona discharge established between two electrodes flush mounted on the surface of the test profile. Two cases are investigated. First, one considers the application of the corona to an airflow which is naturally detached at the trailing edge of the test profile and the experiments is repeated with an airflow naturally attached. In this paper, the behavior of the discharge with free air stream up to 35 m/s and measurements by particle image velocimetry for a velocity range from 6 to 16 m/s are presented. The results show that: 1) the discharge regime depends on the free air stream velocity; 2) when the airflow is naturally detached, the corona discharge allows increasing the velocity and the thickness of the mixing layer; 3) when the airflow is naturally attached, it is possible to reduce the velocity and to increase the thickness of the mixing layer; and 4) using a pulse discharge, one observes that the effect of the actuator on the mixing layer is different according to the discharge frequency. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Electronic properties of single-wall carbon nanotubes and their dependence on synthetic methods

    Page(s): 1215 - 1219
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1280 KB) |  | HTML iconHTML  

    Since their discovery in 1991, carbon nanotubes have been intensively studied, and a number of new applications have been identified. Applications range from nanoelectronics to hydrogen absorption for battery electrodes and fuel cells. Because of their high electrical conductivity and strength, high sensitivity atomic force microscopes already use carbon nanotubes for their tips, and carbon nanostructures are also used as electron beam emitters for medical and scientific equipment. Electron emission is directly correlated with the work function and the ionization potential of carbon nanotubes. Gaussian 98 software was used to perform theoretical quantum calculations on a limited set of HyperChem 5.01 simulated metallic single-wall carbon nanotubes. These initial sets of calculations show that bandgaps and work functions of these small carbon nanostructures are dependent upon the diameter of the tubes, and to a lesser degree so is the ionization potential. In addition, we demonstrate how the manufacturing methods can directly affect the diameter of the nanotubes produced, and therefore directly influence the electrical properties of the nanotubes. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Aluminum surface treatment using three different plasma-assisted dry chemical processes

    Page(s): 1220 - 1225
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB) |  | HTML iconHTML  

    Aluminum plate surfaces having hydrophilic and corrosion-resistant properties are often required for various mechanical parts or systems. The conventional process for treating aluminum surfaces employs a series of wet processes: grease or organic compounds removal followed by drying, chromate process followed by drying, and finally chemical treatment to achieve hydrophilic property. However, the use of chromium (Cr+6) in the chromate process creates an environmental problem. A simple and economic dry process was investigated to replace the conventional aluminum surface treatment, i.e., nonthermal plasma followed by the chemical process. Among several nonthermal plasma processes, two types of plasma jets (60-Hz ac plasma and RF plasma) and the pulsed-corona plasma were investigated. The adhesive characteristics between the aluminum surface and the corrosion-resistant chemical were evaluated by the accelerated corrosion test, i.e., copper-accelerated acetic acid spray (CASS) test. RF plasma with more than 30 s of exposure time followed by the epoxy-type corrosion-resistant coating showed a superior performance over the conventional chromate wet process. Pulsed corona process was nearly equal to the conventional process. Therefore, the conventional wet chemical process for aluminum treatment can be replaced by the newly developed plasma-assisted chemical process. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Contact charging between metals revisited

    Page(s): 1226 - 1230
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (360 KB) |  | HTML iconHTML  

    The theory of contact charging between metals was established in 1951 by Harper and confirmed experimentally in 1975 by Lowell who measured the net charge after separation of pure metals in contact and related it to the contact potential difference and capacitance of the surfaces using a specialized measurement technique. It is generally assumed that these contact charges can be ignored for metals used in common industrial processes because of charge backflow on separation. A series of experiments carried out on commonly used industrial materials shows that net charge does exist on spherical metal balls rolling out of a metal tube into a Faraday pail. The experiments were carried out using three different tube materials (copper, brass, aluminum), five different ball materials (copper, brass, aluminum, steel, and stainless steel), for ball diameters ranging from 0.24 to 1.27 cm. The surfaces of the materials were only rinsed with water and dried. Analysis of the results shows general agreement with the Harper theory and confirms the presence of net charge on metals separated in this simulated industrial operation, i.e., moving metal parts off a conducting conveyor. This process is analyzed from the point of view of possible discharge hazards and the reasons why this phenomenon is not more widely observed in industrial processes are discussed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Charge relaxation due to surface conduction on an insulating sheet near a grounded conducting plane

    Page(s): 1231 - 1238
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (336 KB) |  | HTML iconHTML  

    Electrostatic charges are responsible for a variety of problems in industrial processes and customer equipment that use webs or sheets. Problems include particle contamination from attracting dust, sheets that stick to each other, and electrical discharges resulting in logic resets or damage to electrical components. These problems can be mitigated by increasing the surface conductivity of the insulating sheets by coating the surface with a conductive layer or by increasing the relative humidity. To mitigate problems, electrostatic charge must dissipate quickly compared with the mechanical transport time of the process. Reported here are the results of a model calculation of the charge relaxation time showing explicitly that the charge relaxation time depends on both surface conductivity and geometry. The charge relaxation time is found to increase as the distance to a nearby, grounded conducting plane decreases. Charge relaxation is slowed because the tangential electric field needed to drive surface current becomes smaller as the distance to the grounded plane decreases. Inferred from this analysis is the dependence of charging on the electric Reynolds number (ratio of the electrical charge relaxation time to the mechanical transport time). Web charging can be divided into three regimes: dissipation (Re<0.1), transition (0.1e<10), and charging (10e). Only in the transition regime does charging depend strongly on surface conductivity and speed. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Numerical modeling of inhaled charged aerosol deposition in human airways

    Page(s): 1239 - 1248
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (960 KB) |  | HTML iconHTML  

    A new numerical modeling of inhaled charge aerosol has been developed based on a modified Weibel's model. Both the velocity profiles (slug and parabolic flows) and the particle distributions (uniform and parabolic distributions) have been considered. Inhaled particles are modeled as a dilute dispersed phase flow in which the particle motion is controlled by fluid force and external forces acting on particles. This numerical study extends the previous numerical studies by considering both space- and image-charge forces. Because of the complex computation of interacting forces due to space-charge effect, the particle-mesh (PM) method is selected to calculate these forces. In the PM technique, the charges of all particles are assigned to the space-charge field mesh, for calculating charge density. The Poisson's equation of the electrostatic potential is then solved, and the electrostatic force acting on individual particle is interpolated. It is assumed that there is no effect of humidity on charged particles. The results show that many significant factors also affect the deposition, such as the volume of particle cloud, the velocity profile and the particle distribution. This study allows a better understanding of electrostatic mechanism of aerosol transport and deposition in human airways. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • TCE decomposition by the nonthermal plasma process concerning ozone effect

    Page(s): 1249 - 1256
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (584 KB) |  | HTML iconHTML  

    Dilute trichloroethylene (TCE) and other volatile organic compounds (VOC) in air were decomposed by using the nonthermal plasma process combined with catalysts. To enhance the energy efficiency of the TCE decomposition, some catalysts were tested including their location. It was found that the newly proposed indirect process (VOC cannot be exposed in the plasma region) can also decompose TCE and other VOCs which is due to the ozone dissociation effect. The manganese oxide dissociates ozone to generate oxygen radicals which decompose TCE and other VOCs. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Micro-stepping control of a two-phase linear stepping motor with three-phase VSI inverter for high-speed applications

    Page(s): 1257 - 1264
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (504 KB) |  | HTML iconHTML  

    This paper presents a synchronous frame current control scheme for micro-stepping a two-phase linear stepping motor drive using a three-phase voltage-source inverter. Because of the wide operating frequency, the frequency-dependent voltages are decoupled from the controller to reduce the current-following errors and preserve the dynamic characteristics as the frequency varies. A motor cogging force compensation scheme performed in the synchronous frame is proposed to reduce the positioning error and velocity ripple caused by the cogging force. A space-vector pulse width modulation scheme is used for motor voltage modulation. This scheme is based on the harmonic injection principle originally derived for three-phase motor drives. Good static and dynamic performance is obtained in the experimental verifications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Matched pair of CoolMOS transistor with SiC-Schottky diode - advantages in application

    Page(s): 1265 - 1272
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (792 KB)  

    The new CoolMOS C3 generation combines extremely high on-state conductivity with ultrafast switching speed at full pulse current capability. In the first generation of CoolMOS the saturation current was intentionally reduced at the cell level for the benefit of short-circuit ruggedness. This technique results in a reduced current capability of the device at low gate voltages, which has been overcome today by the C3 family. In some applications the outstanding switching performance of the CoolMOS cannot be utilized due to the dynamic behavior of the diode. For this reason a whole family of SiC diodes has been developed to attain the ideal matched pair of switch and ultrafast diodes. The goal of ultralow-loss applications in switched mode power supplies, power factor correction circuits, and motor control units will be achieved perfectly. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Rated overload Characteristics of IGBTs for low-voltage and high-voltage devices

    Page(s): 1273 - 1280
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (816 KB) |  | HTML iconHTML  

    By a vertical shrink of the nonpunchthrough insulated gate bipolar transistor (NPT IGBT) to a structure with a thin n-base and a low-doped field stop layer a new IGBT can be realized with drastically reduced overall losses. In particular, the combination of the field stop concept with the trench transistor cell results in an almost ideal carrier concentration for a device with minimum on-state voltage and lowest switching losses. This concept has been developed for IGBTs and diodes from 600 V up to 6.5 kV. While the tradeoff behavior (on-state voltage VCEsat or VF to tail charge) and the overall ruggedness (short circuit, positive temperature coefficient in VCEsat, temperature independence in tail charge, etc.) is independent of voltage and current ratings the switching characteristics of the lower voltage parts (blocking voltage VBr<2 kV) is different in handling to the high-voltage transistors (VBr>2kV). With the HE-EMCON diode and the new field stop NPT IGBT up to 1700 V there is almost no limitation in the switching behavior, however, there are some considerations-a certain value in the external gate resistor has to be taken. High-voltage parts usually have lower current density compared to low-voltage transistors so that the "dynamic" electrical field strength is more critical in high-voltage diodes and IGBTs. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Compensation of cable voltage drops and automatic identification of cable parameters in 400 Hz ground power units

    Page(s): 1281 - 1286
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (384 KB) |  | HTML iconHTML  

    In this paper a new cable voltage drop compensation scheme for ground power units (GPU) is presented. The scheme is able to predict and compensate the voltage drop in an output cable by measuring the current quantities at the source. The prediction is based on an advanced cable model that includes self and mutual impedance parameters. The model predicts the voltage drop at both symmetrical and unbalanced loads. In order to determine the cable model parameters an automatic identification concept is derived. The concept is tested in full scale on a 90-kVA 400-Hz GPU with two different cables. It is concluded that the performance is significantly improved both with symmetrical and unsymmetrical cables and with balanced and unbalanced loads. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A high-efficiency magnetic component with superior caloric performance for low-profile high-density power conversion

    Page(s): 1287 - 1293
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (712 KB) |  | HTML iconHTML  

    This paper describes a magnetic component structure that features both low profile and the ability to achieve very high power and energy densities. A key characteristic which enables reaching both of these objectives is the incorporation of a foil winding with a high packing density and a unique shape factor, which enhances thermal and electromagnetic performances simultaneously. Although implementation of foil windings is common practice in magnetic component design, vertically wound foils to achieve low profile is not. Three prototype inductors are compared to a conventional litz-wound E-core inductor. Power dissipation and temperatures are measured in several different experimental procedures. At 140 kHz a power density of 1.8 kVA/in3 was achieved for a measured efficiency of 99.5% and a steady-state hot spot temperature rise above the ambient of only 55°C. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • International standards for the induction motor efficiency evaluation: a critical analysis of the stray-load loss determination

    Page(s): 1294 - 1301
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (656 KB) |  | HTML iconHTML  

    Motor efficiency has to be measured or calculated in accordance with international standards. The most important standards are the IEEE 112-B, IEC 34-2, and JEC 3 . In this paper, a comparison of the measurement procedures defined by these international standards is reported, together with some comments on the prescribed methodologies. The comparison is based on experimental results obtained by tests on four general-purpose three-phase induction motors. The stray-load loss measurement represents a critical key for the correct evaluation of the motor efficiency. For this reason, a critical analysis of this type of losses has been performed. In particular, in order to understand which are the most critical quantities that influence their evaluation, the stray-load loss sensitivity to the measurement errors is analyzed. In the final part of the paper the temperature influence, on the conventional iron losses, is experimentally analyzed. The performed tests show that the temperature difference between the no-load test and the motor real operative conditions is not negligible. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • A detailed model of induction machines with saturation extendable for fault analysis

    Page(s): 1302 - 1309
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (872 KB) |  | HTML iconHTML  

    A review of the literature suggests that modeling of induction machines with saturation has received considerable attention. Most of these models are very application specific. None of them, however, seems to be completely adequate for the purpose of fault diagnosis. This is because for a noninvasive detection technique such as Motor Current Signature Analysis (MCSA), one has to detect different frequency components in the line current of the machine. Incorporation of saturation in the induction machine model will help in identifying and analyzing harmonics in the line current spectra that may arise due to the interaction of saturation with a specific fault. The present paper attempts to create such a model. The model uses modulation of air-gap permeance in order to emulate saturation. Modified winding function approach (MWFA) has been used to model the induction machine with saturation. To demonstrate the effectiveness of the model, certain high-frequency harmonics that can be predicted theoretically are shown to be present in the line current of the simulated machine. Experimental results also confirm the presence of these harmonics. The author plans to extend this model in the future for fault analysis. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analytical approach to cogging torque calculation of PM brushless motors

    Page(s): 1310 - 1316
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (864 KB) |  | HTML iconHTML  

    This paper discusses the approach to analytical calculation of the cogging torque in permanent-magnet (PM) brushless motors. Magnetic field energy in the air gap has been used to obtain the cogging torque equations. Two equations have been derived: with the PM circumferential width taken into account, and a simplified equation, i.e., without the effect of the finite width of the PM. The effect of eccentricity has also been included. Calculation results have been compared with laboratory test results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Identification of linear synchronous reluctance motor parameters

    Page(s): 1317 - 1324
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1416 KB) |  | HTML iconHTML  

    This paper deals with experimental methods for the identification of linear synchronous reluctance motor (LSRM) parameters. A magnetically nonlinear two-axis dynamic LSRM model is derived. This model accounts for the effects of slotting, saturation, cross-saturation, and the end effects. The parameters of the obtained model are not constant. They are given by the characteristics of the flux linkages, thrust, and friction force depending on the mover position and the direct (d) and quadrature (q) axis currents. These characteristics are determined experimentally by a controlled voltage-source inverter employing closed-loop current control in the d-q reference frame. The proposed model, experimental methods, and determined characteristics are confirmed through a comparison between the measured and calculated results. Two tests are performed: a test at the locked mover, and kinematic control at low speed. The effects of cross saturation under dynamic operating conditions and the effects of slotting can be clearly seen in the measured and calculated results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Core losses in motor laminations exposed to high-frequency or nonsinusoidal excitation

    Page(s): 1325 - 1332
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (608 KB) |  | HTML iconHTML  

    This paper first reviews three internationally standardized core loss measurement methods: the Epstein frame, toroids, and single sheet testers. A comparison of the Epstein frame and toroid test results is presented for annealed and unannealed steel. Two methods are used to predict core losses under nonsinusoidal supplies. The first method uses the Fourier series and an improved loss separation algorithm to predict no-load core losses under brushless DC motor flux waveform excitation with a flux density known spectrum. The second method uses the form factor concept and an improved loss separation algorithm to predict core loss. The combination of the improved loss separation algorithm and the form factor concept was found to yield results close to the measured losses under high-frequency supplies, such as pulsewidth-modulated waveforms. An Epstein frame with commercial 0.0140-in (0.356 mm) electrical steel was used for direct core loss measurements; the methods and test bench used are detailed in the paper, along with test results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Modeling of axial flux permanent-magnet machines

    Page(s): 1333 - 1340
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1000 KB) |  | HTML iconHTML  

    In modeling axial field machines, three-dimensional (3-D) finite-element method (FEM) models are required in accurate computations. However, 3-D FEM analysis is generally too time consuming in industrial use. In order to evaluate the performance of the axial flux machine rapidly, an analytical design program that uses quasi-3-D computation is developed. In this paper the main features of the developed program are illustrated. Results given by the program are verified with two-dimensional and 3-D finite element computations and measurements. According to the results, it is possible to evaluate the performance of the surface-mounted axial flux PM machine with reasonable accuracy via an analytical model using quasi-3-D computation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Parameter measurements to study surge propagation in induction machines

    Page(s): 1341 - 1348
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (3008 KB) |  | HTML iconHTML  

    Winding failures in induction machines have been a major concern in the past several years, and more so recently with the addition of variable-speed drives (VSDs). Both the introduction of the vacuum breaker, and the use of pulsewidth-modulation (PWM) drives, utilizing fast switching insulated gate bipolar transistors, have resulted in an increase in winding failures in induction machines. Two mechanisms that cause winding failures are steep-fronted surges, like those caused during the opening and closing of vacuum breakers, and transient overvoltages caused by impedance mismatch between the cable and load during VSD operation. There has been a fair amount of work done to date on the propagation of vacuum-breaker-induced steep-fronted surges in the windings of the induction machine. More recently, work has been progressing on overvoltages at the machine terminals as a result of VSDs operating with long cables connecting the drive and machine. However, the propagation of these surges down the coils and the interference of these PWM surges with each other in the coils as well as the coupling between turns and coils have not been thoroughly investigated. Such an investigation would allow more benign PWM strategies to be developed, which do not build up in the machine to unacceptably high levels. The relevant parameters to be used are unknown and difficult to calculate and measure. To this end, this paper presents a measurement technique to determine the machine parameters for surge studies in machines. Detailed parameter measurements are made of each turn section (slot versus overhang), which are then used to determine the surge impedance of each section. Also included are the mutual capacitive and inductive couplings. Reflection and refraction coefficients are calculated which may then be used for further analysis of surges in machines. 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