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Industrial Electronics, IEEE Transactions on

Issue 2 • Date Apr 1991

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Displaying Results 1 - 10 of 10
  • Design of a novel AC regulator

    Page(s): 89 - 94
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (428 KB)  

    A design in which an AC-to-AC electronic transformer is connected in series with the AC mains to provide a regulated AC output voltage is described. The approach reduces the required voltage and power ratings of the circuit components in the electronic transformer and indirectly increases the conversion efficiency. Since the transformer is designed to accept AC mains directly as the input, no rectifier or mains frequency filtering circuit is required. This, together with the high switching frequency, allows the design of small-size and high-efficiency AC regulators for practical use. An experimental 50 W regulator has been designed to give a typical efficiency of 96% View full abstract»

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  • Cooperative scheduling and its application to steelmaking processes

    Page(s): 150 - 155
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (580 KB)  

    A cooperative approach to scheduling problems is proposed, and its application to creating daily schedules for steelmaking processes is described. In cooperative scheduling, procedures, rules, and the user cooperate to make a feasible schedule efficiently. The procedures, collectively called a scheduling engine, work as a local constraint satisfier to solve general primitive constraints. Rules that represent domain-dependent knowledge then solve the domain-specific constraints by means of a pattern-matching function. The user evaluates the schedule and modifies it by means of a user-friendly interface with direct-manipulation functions. The user interaction is therefore included in the system architecture as a global constraint satisfier. The iteration of this cycle improves the schedule until it becomes feasible. Experimental results obtained with Scheplan, the scheduling environment that applies this approach to scheduling steelmaking processes, show that the daily scheduling time is much less than in manual scheduling and the quality of the schedule is much improved View full abstract»

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  • Circuit board inspection using a range camera

    Page(s): 142 - 149
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (612 KB)  

    A high-speed, high-accuracy three-dimensional (3-D) range camera that possesses sufficient speed and accuracy to inspect circuit boards in real time is presented. The architecture of the system is briefly described, and the algorithms used to make quantitative presolder measurements, including the orientations and lengths of leads and the locations and shapes of holes, are examined in detail. Since the unit runs in real time and performs sophisticated image analysis functions, considerable emphasis in the algorithm development was placed on the ability to partition tasks between general-purpose computers and array processors View full abstract»

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  • Design of a high-frequency planar power transformer in multilayer technology

    Page(s): 135 - 141
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (540 KB)  

    A high-frequency power transformer using multilayer printed circuit board (ML-PCB) technology is presented for applications in switched-mode power supplies operating at frequencies up to several megahertz. The mechanical configuration of laboratory prototypes is discussed, as well as the electrical, parasitic, and thermal behavior. The focus is on the leakage inductance, since the analysis of other aspects is relatively simple. Test results show that the transformer has high efficiency, low leakage inductance, good thermal behavior, and good line insulation properties. The topology enables the designer to make a trade-off between leakage inductance and interwinding capacitance. Due to the well-defined geometry, parasitic interwinding capacitance and leakage inductance are reproducible and can be computed relatively easily View full abstract»

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  • Comparison of two techniques for closed-loop drive of VR step motors without direct rotor position sensing

    Page(s): 95 - 101
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    Closed-loop control of variable-reluctance (VR) step motors without using direct rotor-position sensing is investigated. Two nondirect rotor-position sensing techniques, namely the waveform detection (WD) and the pulse-width-modulation (PWM) techniques, were implemented and applied to a four-phase (15° step-angle) VR step motor. Test results show that a DC shunt motor and a DC series motor type of performance can be achieved from the step motor with PWM drive and WD drive, respectively. The stability problem encountered with the existing PWM controller due to motional EMF effects at higher operating speeds is investigated, and modifications are suggested to include speed as an additional control signal to make the system more stable. With the inclusion of the speed signal, the operating speed of the test motor is from 1000 to 1750 r/min. The performances for the two techniques are compared, and experimental results are presented View full abstract»

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  • Characteristics of electric power transmission on high-frequency inverter having distributed constant line at load side

    Page(s): 115 - 120
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (420 KB)  

    An induction heating system aimed at improving the characteristics of high-frequency power supplied from the high-frequency, inverter to the parallel resonant load circuit is proposed, and its transmission efficiency is studied. In this system, high-frequency power can be supplied by lowering the effect of the inductance component accompanied by wiring between the inverter circuit and the resonant load circuit. Impedance matching between the inverter and the resonant circuit and high-efficiency power transmission from the inverter to the load circuit are possible. If a flexible coaxial cable is used as the distributed constant line, it is easy to cope with the case in which comparative distance exists between the inverter part and the heating part or the case in which the heating part is moved View full abstract»

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  • A discrete time variable structure controller for a brushless DC motor drive

    Page(s): 102 - 107
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (448 KB)  

    The design and the microprocessor-based implementation of a variable-structure-strategy (VSS) controller for a brushless DC motor drive are described. The controller is a conventional variable-structure design in the continuous-time domain. However, the microprocessor implementation using a constant sample period implies that full sliding mode is not achieved. The properties of the quasi-sliding that results are explored. It is shown that the sliding line expands into a sliding region, which can be described as a sector. The size of this sector is related to the sampling period and the switching gains. A modified design procedure is proposed for discrete-time VSS design. The design was verified on an experimental set-up, which generated variations in system parameters as well as external load disturbances View full abstract»

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  • Analysis and design of an unusual unity-power-factor rectifier

    Page(s): 126 - 134
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    A unity-power-factor rectifier that has a parallel-resonant tank tuned to the second harmonic of the line frequency is analyzed for two filter configurations. A unidirectional-power-flow version of the current-sourced rectifier can operate stably open loop or can be current limited down to zero output voltage. The large inductor normally required is an outstanding disadvantage which can be partially overcome using a resonant filter. The design-oriented analysis includes variable-frequency operation and key component ratings. A design procedure is suggested, and complete experimental verification is obtained using a 120 V, 500 W. 60 Hz rectifier switching at 50 kHz View full abstract»

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  • A three-phase half-controlled rectifier with pulse width modulation

    Page(s): 121 - 125
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (432 KB)  

    A three-phase pulse-width-modulated (PWM) half-controlled rectifier using a novel PWM control strategy whereby the low-order harmonic content in both the input current and the output voltage is reduced is presented. The circuit operates with a unity displacement factor at its input and uses minimum power components. The PWM strategy developed can be implemented on a three-phase half-controlled rectifier bridge with only three controlled switches to obtain PWM controlled rectification. Although the circuit operation is explained with force-commutated SCR switches, the basic controlled PWM operation is valid for any type of switch control. The circuit has wide applications ranging from rectifiers to battery chargers to motor drives. Even if an input current filter is desired, its size will be small due to the PWM pattern used View full abstract»

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  • The analysis and compensation of dead-time effects in PWM inverters

    Page(s): 108 - 114
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (880 KB)  

    The quantitative prediction of the dead-time effect in pulse width modulated (PWM) inverters is addressed. Through analysis and simulation it is shown that the effect results in a decrease of the fundamental component and an increase in the low-order harmonics in the output voltage of the inverter. To compensate the effect, two simple methods, which are adequate for sinusoidal PWM and memory-based PWM, respectively, are presented. Experimental results show the validity of the analysis and the usefulness of the compensation methods View full abstract»

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Aims & Scope

IEEE Transactions on Industrial Electronics encompasses the applications of electronics, controls and communications, instrumentation and computational intelligence for the enhancement of industrial and manufacturing systems and processes.

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Meet Our Editors

Editor-in-Chief
Carlo Cecati
DISIM - Univ. degli Studi dell'Aquila
67100 Aquila, Italy
c.cecati@ieee.org
Phone: +39 0862 434 450
Fax: +39 0862 1960 411