IEEE Transactions on Industry Applications

Several attempts have already been made to simulate particle trajectories in roll-type electrostatic separators. However, the predictive value of the results is limited by an excessive number of simplifying assumptions regarding the electric field distribution, as well as particle charging and discharging mechanisms. The present work is aimed at improving the existing models by taking into account... View full abstract»

Plate-type electrostatic separators are commonly used for the selective sorting of conductive from nonconductive constituents of a granular mixture. This paper addresses the more delicate issue of granular materials that are characterized by finite nonzero resistivities. The study was conducted with three materials having similar granule size range and specific weight but slightly different electr... View full abstract»

Electrostatic discharge (ESD) damage to giant magnetoresistive (GMR) heads is investigated using a charged device model tester. The sensor of a GMR head is easily affected by ESD during handling in production. Simulation of the picking procedure reveals that elevating such a small-capacitance device above the work surface increases the potential by up to ten times and the discharge current by up t... View full abstract»

Various models have evolved to test the sensitivity of electronic devices to electrostatic discharge (ESD), which include the human body model, machine model, and field-induced charged device model. The objective of this paper is to review both the static and dynamic aspects of these models and to analyze the charge and potential control of ESD events. Charge and geometry sensitivity factors are d... View full abstract»

An atmospheric low-temperature plasma flow generated by a microwave discharge utilizing a coaxial cable for microwave transmission was utilized for the inactivation of a bacteria. The employed device consists of a cavity, a quartz discharge tube, a coaxial cable, a microwave power source, and a gas supply system. Using this argon plasma source, we attempted to clarify the effects of exposure tempe... View full abstract»

This paper presents a new rigorous approach to the calculation of current ratings in pipe-type cables with slow circulation of the fluid. Detailed mathematical analysis is presented for the calculation of the hot-spot fluid temperature as a function of the cable geometry and the fluid inlet temperature. The emphasis is placed on real-time applications, in which the pipe-surface temperature is meas... View full abstract»

Capacitors are widely used for power-factor correction (PFC) in power systems. When a PFC capacitor is installed with a certain load in a microgrid, it may be in parallel with the filter capacitor of the inverter interfacing the utility grid and the local distributed-generation unit and, thus, change the effective filter capacitance. Another complication is the possibility of occurrence of resonan... View full abstract»

This paper discusses a new method to detect rotor eccentricity faults in induction motors using a so-called surge test that is applied to the stator windings. Rotor eccentricity faults cause an asymmetrical air gap in induction motors, which makes the surge waveform shape depend on rotor position. The change of surge waveform per revolution can be used to indicate any abnormal air gap problem clea... View full abstract»

This paper describes an automatic computer-controlled acoustic resonance detection workbench for high-intensity-discharge (HID) lamps. The detection method is based on optical measurements of the discharge arc path. With the aid of a dual lens projection system, relative light intensity measurements at different points of the arc are guided by fiber optic to a photodiode array. These measur... View full abstract»

Current-pulse-fed high-pressure-sodium lamps generate audible noise even if lamp power frequency does not excite longitudinal acoustic resonance modes inside the arc tube. This noise is caused by magnetostriction in conductive parts of the arc tube-supporting frame and in the wires passing through the seal of the outer glass envelope. Conductor dimensional changes effectively couple mechanical ene... View full abstract»

This paper presents a computationally efficient technique in determining the influence of the finite axial length of the permanent magnets on the rotor eddy-current loss in modular brushless ac machines. The technique is employed to quantify the effectiveness of axially segmenting the permanent magnets of four-phase, eight-slot, ten-pole and five-phase, ten-slot, 12-pole brushless machines, which ... View full abstract»

This paper deals with the endwinding cooling problems of totally enclosed fan-cooled (TEFC) induction motors. In order to obtain information about the phenomena involved in the motor end space, three "ad hoc" prototypes have been built. The complete test-bench setup, together with the followed test procedures, is reported in detail. The measurement results have shown that all the motor-part overte... View full abstract»

Permanent-magnet machines using concentrated windings are gaining popularity at the expense of distributed windings in various applications, mainly due to cost savings. The result is often an increased amount of parasitic effects like ripple torque, alternating magnetic fields in the rotor, unbalanced radial forces, and magnetic noise. This paper describes the reasons for the parasitic effects, in... View full abstract»

A three-phase induction motor model that depicts the motor behavior over a wide range of frequencies from 10 Hz to 10 MHz is presented in this paper. The model is universal in the sense that common-mode, differential-mode, and bearing circuit models are combined into one three-phase equivalent circuit model. The proposed model is basically an extension of the low-frequency IEEE Standard 112 circui... View full abstract»

The demand for high-efficiency electric motor drives at low cost is increasing, particularly, in high-volume applications, such as household appliances. Single- and two-phase machines are viable under such constraints. Between them, two-phase switched reluctance motor drives are preferred from the viewpoint of performance. This paper presents a novel two-phase switched reluctance machine (TPSRM) t... View full abstract»

This paper proposes an online compensation strategy for the unwanted disturbance voltage resulting from the zero- current clamping effect for high-frequency-signal-injection-based sensorless control schemes. We derive an analytical model that reveals intrinsic characteristics of the zero clamping effect for high- frequency signal injection. The model in this form is subsequently incorporated into ... View full abstract»

In this paper, the rotor position of a synchronous reluctance motor is estimated exploiting the natural saliency of the machine through an addition of a small high-frequency sinusoidal voltage to the stator voltage reference. Due to rotor saliency, a stator voltage component is generated orthogonal to the added signal, whose amplitude depends on the phase displacement between the d-axis and the di... View full abstract»

Inverter-induced high-frequency bearing currents are a parasitic effect that can occur in variable-speed drive systems. While the physical cause-and-effect chains are understood, little has been known on appropriate quantitative assessment of the phenomena. This paper discusses reliable techniques for the measurement of different parameters of importance for the bearing damage assessment, includin... View full abstract»

A mathematical model that Is developed for a generalized drive system, including common-mode passive and active elements, is used to explore the issues of paralleling soft-switched resonant dc-link drive systems. Differences between the modulation pattern for each drive system cause common voltage disturbances, which lead to significant circulating currents between the drive systems. Control metho... View full abstract»

This paper presents the careful integration of a newly proposed Z-source topological concept to the basic neutral-point-clamped (NPC) inverter topology for designing a three-level inverter with both voltage-buck and voltage-boost capabilities. The designed Z-source NPC inverter uses two unique X-shaped inductance-capacitance (LC) impedance networks that are connected between two isolated dc input ... View full abstract»

An area of interest for dynamic voltage restorer (DVR) research is the damping of transient oscillations initiated at the start and at the recovery instant from a voltage sag. Nonlinear loads, with harmonic currents close to the DVR filter resonance frequency, can also excite the resonance oscillations. To compensate voltage sags and dampen high-frequency oscillations simultaneously, an investigat... View full abstract»

High power conversion efficiency is an important requirement of the front-end power-factor-corrected (PFC) boost rectifier that is used in shaping the ac input current in a typical modern switch-mode power supply. A reasonably accurate estimate of the power losses in individual components is essential in order to improve the efficiency of the PFC rectifier. In this paper, difficulties in the measu... View full abstract»

This paper presents the analysis, design, and implementation of a parallel-inverter system with failure isolation and hot-swap features. The system is controlled with a system control unit to achieve output voltage regulation, inverter synchronization, and the aforementioned features. By incorporating a current- weighting-distribution control, the system allows inverters with identical or differen... View full abstract»