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Applied Power Electronics Conference and Exposition, 1990. APEC '90, Conference Proceedings 1990., Fifth Annual

Date 11-16 March 1990

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  • APEC '90. Fifth Annual Applied Power Electronics Conference and Exposition. Conference Proceedings. (Cat. No.90CH2853-0)

    Publication Year: 1990
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    Freely Available from IEEE
  • A resonance power supply that provides dynamic power factor correction in capacitor input off-line converters

    Publication Year: 1990 , Page(s): 563 - 570
    Cited by:  Papers (5)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (443 KB)  

    A dynamic power factor corrected resonance power supply employing a single high-speed gate-turn-off (GTO) thyristor is presented. Included is a description of the modes of operation and the design and evaluation of a 300 W, 80 kHz prototype model. Computer simulation of the prototype circuit is also discussed. An assessment of the possibility of using the converter for low-voltage applications is presented.<> View full abstract»

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  • Real-time, dynamic controller for dynamic power filters in supplies with high contamination

    Publication Year: 1990 , Page(s): 571 - 578
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    A real-time, closed-loop controller system for controlling active power compensators under rapidly varying load conditions is proposed. With the aid of a dedicated signal processor, using correlation algorithms, real-time, analog compensation reference signals for dynamic power compensators are generated. In order to facilitate a cost-effective compensation system, separate compensation of the fundamental reactive power component and the harmonic components is further proposed. An algorithm time of 312 mu s in a 50 Hz system is achieved, providing an effective controller system bandwidth of 1.6 kHz.<> View full abstract»

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  • Predicting power factor and other input parameters for switching power supplies

    Publication Year: 1990 , Page(s): 579 - 587
    Cited by:  Papers (13)
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    Modeling and analysis methods are presented which provide a complete, real-time description of the power supply circuit being analyzed, yielding values for power factor and other input parameters. The algorithm can be entered into a small computer of programmable calculator, and the effects of component value changes can easily be seen by changing the corresponding constant in the program. Because all electrical parameters are calculated as a function of time, RMS, mean, and average values are easily obtained. The analysis technique used is an important tool for design and analysis applications and can be applied to other types of circuits as well.<> View full abstract»

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  • Phase-controlled rectifier line-current harmonics and power factor as a function of firing angle and output filter inductance

    Publication Year: 1990 , Page(s): 588 - 597
    Cited by:  Papers (7)
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    Normalized design relationships are presented for line-current harmonics, line-current fundamental phase angle, displacement power factor, purity factor, overall power factor, and DC output voltage as a function of firing angle and noninfinite output filter inductances for both single- and three-phase phase-controlled rectifiers. The design relationships are useful for both the analysis of existing rectifiers and the design of new rectifiers. These accurate design relationships are essential for attacking the problems caused by high rectifier line-current harmonics and low power factor.<> View full abstract»

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  • Computer simulation of power line harmonics or conducted emission generated by 6-pulse and 12-pulse rectifiers

    Publication Year: 1990 , Page(s): 598 - 602
    Cited by:  Papers (1)
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    The simulation of the rectifier circuits in a SPICE model is described, and the distorted line current waveforms and the spectrum of harmonic currents are shown. A reduction of harmonic content from the theoretical percentage was determined when the source impedance and the leakage inductance of a transformer are considered. The 12-pulse rectifier with 16.6% source reactance could reduce the 11th harmonic to 2.5%, which is less than MIL-STD-461 requirement.<> View full abstract»

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  • Comparison of two circuit-level simulation techniques for power-processing circuits

    Publication Year: 1990 , Page(s): 605 - 611
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    Two circuit-level simulation techniques are discussed-the well-known state-space averaging technique and direct solution of the state-space equations. The direct solution technique seems well suited for trying out new ideas for quickly checking designs. All of the important nonlinearities, such as peak current limiting, overcurrent protection, and error amplifier saturation, can be included. It is better to choose the averaging technique for simulating complex switching converters or power systems. An important limitation of the averaging technique is the inability to produce switching frequency information, such as transistor current.<> View full abstract»

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  • Applying software tools to enhance engineering group productivity

    Publication Year: 1990 , Page(s): 612 - 618
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    The purpose of this work is to identify specific tasks that can be supported with software tools, to show how certain software tools can improve the productivity of a power supply design effort, and to demonstrate how several learning-intensive programs can be applied effectively. In a situation where the design time is a major constraint, these programs can effect a superior design. On the other hand, relying too heavily on the software could be a disaster. A simple input error during the modeling process could result in considerable costly rework.<> View full abstract»

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  • Computer-aided design of a DC-to-DC switching converter

    Publication Year: 1990 , Page(s): 619 - 628
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (596 KB)  

    A computer-aided design process for switching converters is discussed. The various types of software tools for supporting this computer-aided design process are surveyed. A design example is given to illustrate the use of the various software tools in the design process. Three major areas in power electronics that require specialized computer-aided design and analysis tools are considered: time-domain switching waveform simulation: frequency-domain analysis and design; and magnetic components design. The use of these tools in a product design cycle is discussed.<> View full abstract»

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  • Multilevel simulation tools for power converters

    Publication Year: 1990 , Page(s): 629 - 633
    Cited by:  Papers (18)  |  Patents (4)
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    Various methods for simulating the large signal behavior of power converters are discussed. Multilevel simulation is the most efficient approach, combining the speed of behavioral circuit description with the accuracy of device models. Results for control optimization and converter loss reduction demonstrate this. Widespread use of the tools and the methodology discussed, however, depends on the availability of proper models for the various circuit components. The problem of accurate device modeling versus simulation speed is addressed, and an example of an efficient design analysis is shown.<> View full abstract»

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  • Quasi real time simulation of power electronic systems

    Publication Year: 1990 , Page(s): 634 - 640
    Cited by:  Papers (1)
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    A software-driven quasi-real-time simulator is presented for power electronic circuits and systems. The use of multiple digital signal processors (DSPs) allows simulations at near-real-time speeds for a wide variety of complex power electronic systems. Digital and analog interfaces with the outside world allow monitoring of the variables while the program is being executed. This interactive feature is especially helpful in complex simulations and in realizing a testbed for actual power electronic controllers. The use of parallel DSPs allows extremely high computation speed, and the use of a bus-based broadcasting technique trims communication overhead to insignificant levels.<> View full abstract»

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  • State-plane animation of power electronic systems: a tool for understanding feedback control and stability

    Publication Year: 1990 , Page(s): 641 - 648
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (350 KB)  

    State-plane animation is discussed as a powerful tool for characterizing feedback control in power electronic systems. The implementation is simple, and the relationship between different types of control schemes and different types of instability can be easily explained in geometric terms. While state-plane animation is primarily restricted to second-order systems, it provides valuable insights into the mathematics of differential geometry for systems of arbitrary dimension.<> View full abstract»

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  • Optimum topology of a self-commutated resonant inverter

    Publication Year: 1990 , Page(s): 651 - 658
    Cited by:  Papers (4)
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    A 10 kW, 50 kHz resonant inverter development effort for a radar transmitter application is presented. Well-behaved and constant loads are not assumed in order to show topology function; rather, the parameters used are a real life set with variations that pose severe design problems. The tradeoffs for circuit topology selection are outlined, and the final high-power full-bridge hybrid topology is shown. An equivalent lower-power half-bridge version of the same hybrid topology is developed. The equivalence is nonobvious. Computer circuit simulations and measured data are used to show performance.<> View full abstract»

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  • Ten kilowatt self-commutated resonant inverter using MOS controlled thyristors

    Publication Year: 1990 , Page(s): 659 - 667
    Cited by:  Papers (5)
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    A 50 kHz full-bridge series/parallel resonant inverter has been developed to provide a 10 kW high-voltage output from 270 V DC input power. The inverter uses MOS controlled thyristors as self commutated switches. Multilayer ceramic chip capacitors and gapped ferrite planar inductors serve as resonant elements to allow high power density. The design, computer simulation, and breadboard evaluation of the inverter are described.<> View full abstract»

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  • Use of GTO as a zero turn-off time thyristor in series resonant inverters

    Publication Year: 1990 , Page(s): 668 - 671
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    A study on the use of gate turn-off (GTO) thyristors as zero-turn-off-time thyristors in series-resonant inverters is presented. A comparative study on the power switches and their commutation mechanisms in series resonant inverters has been made to demonstrate the advantages of this operation mode of GTO below the resonance frequency Zero-turn-off-time operation of GTO thyristors is detailed, and the design of a highly reliable triggering circuit for a self-protected GTO inverter leg is presented. The performances of two series-resonant, inverters using, respectively, asymmetric thyristors and zero-turn-off-time GTOs are studied and compared.<> View full abstract»

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  • High power factor control system in multilevel converters for AC heavy traction drives

    Publication Year: 1990 , Page(s): 672 - 680
    Cited by:  Papers (4)  |  Patents (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (481 KB)  

    A quasi-zero reactive power demand which is mandatory in single-phase AC (25 kV/50 Hz) traction systems is considered. Multilevel converter structures and high-performance control techniques have been developed to fulfil this goal in AC heavy traction drives. The tasks of the three level rectifier are described in detail. The current control logic is particularly suitable for applications to multilevel bridges. Advantages deriving from the use of a medium-voltage converter with three different DC potentials are discussed. Digital simulation performed using the general-purpose electromagnetic transients program made it possible to verify the effectiveness of the regulating techniques on the whole system. By controlling converters suitably, the reactive power flowing was reduced to quasi-zero values having a constant voltage on the DC-link and minimizing the harmonic content of the line current in every load condition. Another regulation technique was studied to balance the voltage on condensers which, acting exclusively on the rectifier and not using dissipating techniques or raising the device switching frequency, manage to keep the unbalance DV within a prefixed band.<> View full abstract»

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  • An advanced programmed PWM modulator for inverters which simultaneously eliminates harmonics and rejects DC link voltage ripple

    Publication Year: 1990 , Page(s): 681 - 685
    Cited by:  Papers (4)
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    A technique for generating programmed pulse width modulated (PWM) waveforms which simultaneously eliminates harmonics and rejects DC-link ripple is proposed. The technique guarantees high-quality inverter output voltage by rejecting the lower-order harmonics generated by the DC-link voltage ripple. In order to achieve this objective, the modulating function in the programmed PWM technique is suitably altered by a feedforward approach. The modulator is useful in situations where voltage ripple in the DC-link is unavoidable, such as when feeding nonlinear loads or when the front-end rectifier supplying the DC-link is fed from a weak AC system which is frequently unbalanced. A design procedure and the digital implementation of the modulator are discussed in detail.<> View full abstract»

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  • Design of a 900 kHz induction heating unit for fast thermal treatment of a small steel wire

    Publication Year: 1990 , Page(s): 686 - 689
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    The analysis and design of an induction heating system for the ultrafast heating of a small-diameter steel wire at 900 kHz are presented. The design of the inductor is carried out using the field computation method, which provides the local distribution of the eddy currents and the heating power in the different parts of the magnetic circuit. The feasibility of a 1 MHz resonant power source is considered, and a self-controlled series resonant inverter using bipolar transistors is proposed. This inverter can supply 60 W at unity power factor with an operating frequency from 800 kHz to 1 MHz. The performance of the heating system is illustrated by experimental results.<> View full abstract»

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  • A new synchronous-switch post regulator for multi-output forward converters

    Publication Year: 1990 , Page(s): 693 - 696
    Cited by:  Papers (25)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (229 KB)  

    A synchronous-switch post regulator (SSPR) circuit based on a novel charge-pump gate drive is described. It resolves the technical barriers due to the difficulty of designing an effective gate drive and synchronized trailing-edge pulse width modulation (PWM) in a straightforward manner. It has been demonstrated that in the medium current range, the power loss of this SSPR is much less than when the linear regulator approach is used. With additional advantages of easy on/off control, better overcurrent protection, and the potential of being integrated into a monolithic IC, this SSPR compares favorably with the magnetic amplifier post regulators.<> View full abstract»

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  • Determination of cross regulation in multioutput resonant converters

    Publication Year: 1990 , Page(s): 697 - 705
    Cited by:  Papers (5)
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    The determination of the cross-regulation characteristics in multioutput resonant converters is examined. The steady-state cross-regulation characteristics are derived using the state-plane techniques, illustrated by the example of a two-output clamped series resonant converter with clamped capacitor voltage. This technique can be applied to any multioutput resonant converter, thus it can serve as an important design tool and a criterion for selecting the optimal topology. The intuition gained from the analysis can be used to reduce the cross regulation in the multioutput power supplies. The theoretical results are verified by simulations and experimental measurements.<> View full abstract»

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  • Using the ohmic resistance reverse conduction capability of MOSFETs in quasi-resonant converters

    Publication Year: 1990 , Page(s): 706 - 711
    Cited by:  Papers (3)
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    A technique is proposed to eliminate the external diodes used to block the MOSFET's parasitic antiparallel diode in full-wave-mode zero-current switching quasi-resonant converters (ZCS-QRCs). The method, which consists of using the ohmic resistance reverse conduction capability of MOSFETs for conducting the negative portion of the resonant inductor current, thus preventing it from flowing into the body diode, has been successfully employed in 300 W, 20 V buck and forward quasi-resonant converters. It has been verified that the method improves efficiency and reduces the cost, size, and weight of ZCS-QRCs. The feasibility of associating MOSFETs in parallel in ZCS-QRCs in order to increase power rating is also demonstrated.<> View full abstract»

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  • Topologies for three element resonant converters

    Publication Year: 1990 , Page(s): 712 - 722
    Cited by:  Papers (38)  |  Patents (4)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (734 KB)  

    A procedure for an orderly examination of multielement resonant topologies has been demonstrated. With this procedure a large number of new three-element topologies have been exposed. Many of the new topologies have interesting and potentially useful properties. Because of the improved filter roll-off characteristic is is often possible to operate three-element topologies with a Q different from that of two-element circuits. This can actually allow a reduction in component currents. A large variety of three-element circuits has been built, and, in practice, efficiency has not proven to be a serious issue.<> View full abstract»

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  • Experimental investigation of the LLC-type parallel resonant converter

    Publication Year: 1990 , Page(s): 723 - 732
    Cited by:  Papers (3)
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    Based on the theoretical analysis of R. Liu et al. (see Proc. High Freq. Power Conv. Conf., p.486-96 (1989)), a complete set of design curves for the LLC-type parallel resonant converter is derived. Using these curves, a design procedure for the converter operating in the continuous conduction mode and with natural commutation is formulated. As an example, a 150 W, 150 kHz, multioutput LLC-type parallel resonant converter power supply was designed and tested. Various test waveforms for the output load variation from 10% load to full load and the input voltage variation from 90 VAC to 130 VAC line voltages are presented. The experimental results and the theoretical values are in good agreement.<> View full abstract»

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  • Two port characterization of DC to DC resonant converters

    Publication Year: 1990 , Page(s): 737 - 745
    Cited by:  Papers (9)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (386 KB)  

    An analytical method based on two-port network theory is developed for DC-to-DC resonant converters. Based on steady-state frequency-domain analysis, a simple two-port model described by g-parameters is presented for these converters. The results obtained are useful for simulation and design of the converters. Simulation results are presented to support the method developed.<> View full abstract»

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  • Simulation of power electronic circuits containing nonlinear inductances using a sampled-data model

    Publication Year: 1990 , Page(s): 746 - 749
    Cited by:  Papers (3)
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    Power electronic circuits which contain nonlinear inductances are described by a set of nonlinear state equations. A sampled-data model is presented for the circuit from which a set of linear state equations can be formulated. In the sampled-data model, the nonlinear inductor is modeled by an ideal sampler, a variable gain, and a clamp. The state variables for the circuit are updated during simulation using a three-step procedure. One step involves the solution of the linear state equations using a technique such as the state transition matrix approach. Two additional steps are employed to account for the effects of the ideal sampler, clamp, and variable gain.<> View full abstract»

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