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Showing papers on "Boost converter published in 1988"


Journal ArticleDOI
02 Oct 1988
TL;DR: In this paper, three DC/DC converter topologies suitable for high power-density high power applications are presented, which operate in a soft-switched manner, making possible a reduction in device switching losses and an increase in switching frequency.
Abstract: Three DC/DC converter topologies suitable for high-power-density high-power applications are presented. All three circuits operate in a soft-switched manner, making possible a reduction in device switching losses and an increase in switching frequency. The three-phase dual-bridge converter proposed is shown to have the most favorable characteristics. This converter consists of two three-phase inverter stages operating in a high-frequency six-step mode. In contrast to existing single-phase AC-link DC/DC converters, lower turn-off peak currents in the power devices and lower RMS current ratings for both the input and output filter capacitors are obtained. This is in addition to smaller filter element values due to the higher-frequency content of the input and output waveforms. Furthermore, the use of a three-phase symmetrical transformer instead of single-phase transformers and a better utilization of the available apparent power of the transformer (as a consequence of the controlled output inverter) significantly increase the power density attainable. >

2,056 citations


Journal ArticleDOI
01 Apr 1988
TL;DR: In this paper, the half-bridge series-resonant, parallel-reonant and combination series-parallel resonant converters are compared for low-output-voltage power supply applications.
Abstract: The half-bridge series-resonant, parallel-resonant, and combination series-parallel resonant converters are compared for use in low-output-voltage power supply applications. It is shown that the combination series-parallel converter, which takes on the desirable characteristics of the pure series and the pure parallel converter, avoids the main disadvantages of each of them. Analyses and breadboard results show that the combination converter can run over a large input voltage range and a large load range (no load to full load) while maintaining excellent efficiency. A useful analysis technique based on classical AC complex analysis is introduced. >

1,795 citations


Journal ArticleDOI
TL;DR: In this paper, a multistage capacitor divider Cuk converter was proposed for a 50 V to 5 V converter with high voltage step-down ratio without a transformer and a very small duty ratio.
Abstract: A novel switching DC-to-DC converter is introduced in which large voltage step-down ratios can be achieved without a very small duty ratio and without a transformer. The circuit is an extension of the Cuk converter to incorporate a multistage capacitor divider. A particularly suitable application would be a 50 V to 5 V converter in which DC isolation is not required. The absence of a transformer and a larger duty ratio permits operation at a high switching frequency and makes the circuit amenable to partial integration and hybrid construction techniques. An experimental 50 W three-stage voltage divider Cuk converter converts 50 V to 5 V at 500 kHz, with an efficiency higher than that for a basic Cuk converter operated at the same conditions. A corresponding voltage-multiplier Cuk converter is described, as well as dual buck-boost-derived step-down and step-up converters. >

298 citations


Journal ArticleDOI
TL;DR: In this article, five basic operating modes of the parallel resonant converter are analyzed and closed-form solutions for the two most important modes are found for the closed form solutions are given graphically so that the designer can use them without lengthy calculation or computer iteration.
Abstract: Five basic operating modes of the parallel resonant converter are analyzed. Three of the modes occur when the output filter inductor is removed and the remaining two occur when the filter inductor is large. Closed-form solutions are found for the two most important modes. Analysis results are given graphically so that the designer can use them without lengthy calculation or computer iteration. Switching frequency, peak tank capacitor voltage, and peak tank inductor current are plotted in the output plane. These plots, with a load line superimposed, show how operating point, frequency, and peak stress vary as load conditions change. Use of the output plane plots to minimize component costs is explained. Comparison of the best designs found for the large and zero filter inductance cases shows that removing the filter inductor can reduce both parts count and tank circuit size while peak transistor current remains unchanged. >

185 citations


Journal ArticleDOI
Loren H. Walker1
02 Oct 1988
TL;DR: In this article, a bidirectional 18-pulse voltage-source converter utilizing gate-turnoff thyristors (GTOs) was described, which was placed in service in early 1988 to connect an energy storage battery to a utility grid.
Abstract: A bidirectional 18-pulse voltage-source converter utilizing gate-turnoff thyristors (GTOs) is described. The converter, which is rated 10 MVA, was placed in service in early 1988 to connect an energy storage battery to a utility grid. The converter is rated and controlled to operate in all four quadrants (discharge, charge, leading VAr, or lagging VAr) at the full 10 MVA rating. It is capable of independent rapid control of real and reactive power with a transient response of 16 ms to changes in commanded value of real or reactive power. Thus it is usable as a reactive power controller (static VAr control), voltage control, frequency control, power system stabilizer, or real power peaking station. For use as a reactive power controller only, no battery would be needed. The design, construction, control, and application of the converter are described, and performance data taken at factory power test and at the installation are given. >

165 citations


Patent
28 Apr 1988
TL;DR: In this paper, a full bridge integrable dc-to-dc converter is described which includes four FET switching devices wherein the parasitic capacitors of the switching devices exchange energy with the leakage and magnetizing inductances of the converter transformer.
Abstract: A full bridge integrable dc-to-dc converter is described which includes four FET switching devices wherein the parasitic capacitors of the switching devices exchange energy with the leakage and magnetizing inductances of the converter transformer. Since energy is exchanged between the passive components of the circuit, the switching is accomplished in a substantially lossless manner. Energy not transmitted to the load is returned to the source rather than being dissipated in the active devices of the converter. Further, single frequency operation is accomplished over a broad range of output conditions by phase shifting the converter legs relative to one another.

135 citations


Patent
18 May 1988
TL;DR: In this article, the output alternating current of the input filter is rectified and electronically switched by buck and boost switching circuits at a frequency much higher than the frequency of the alternating line current input.
Abstract: An AC to DC power converter comprises an input filter for filtering the alternating current input and an output filter for filtering and smoothing the direct current power output to a load. The output alternating current of the input filter is rectified and electronically switched by buck and boost switching circuits at a frequency much higher than the frequency of the alternating line current input. The rectified line current is sensed and provided to a control circuit which controls the operation of the buck and boost switching such that the power line current will follow a predetermined reference voltage waveform.

116 citations


Patent
13 Oct 1988
TL;DR: In this paper, a current mode converter with continuously variable optimized slope compensation and improved power factor is presented, where a ramp signal is generated with a slope that is determined by the loading of the converter.
Abstract: A current mode converter with continuously variable optimized slope compensation and improved power factor is disclosed. In the slope compensation circuit, the output voltage of the converter is sensed and a ramp signal is generated with a slope that is determined by the loading of the converter. The ramp signal is combined with a conventional sensed current signal of the converter to generate a composite sensed current signal which is coupled to the comparator of the converter. The other input to the comparator is a conventional error amplifier and the comparator's output is used to control switching of the converter. In an alternate embodiment, the continuously variable slope compensation circuit is operative using an un-filtered full-wave rectified input voltage waveform. An output is produced for the comparator which is the multiplied product of this input voltage and the output of the converter's error amplifier thereby amplitude-modulating the error signal and providing a composite error voltage that will always be proportional to the unsmoothed input voltage waveform.

111 citations


Journal ArticleDOI
TL;DR: In this article, a power converter suitable for one-step conversion of the single-phase high-frequency link voltage to the three-phase low-frequency voltages typically required for interfacing with system sources and loads was proposed.
Abstract: A single-phase high-frequency link appears to be an attractive alternative to the DC link commonly used in power conversion systems. The authors propose a power converter suitable for one-step conversion of the single-phase high-frequency link voltage to the three-phase low-frequency voltages typically required for interfacing with system sources and loads. The converter utilizes zero voltage switching principles to minimize switching losses and uses an easy-to-implement technique of pulse density modulation for the control of the amplitude, frequency, and waveshape of the synthesized low-frequency signals. Adaptation of the proposed topology for power conversion to single-phase AC and DC voltage or current outputs is shown to be straightforward. The feasibility of the proposed power circuit and the control technique have been experimentally verified. >

106 citations


Proceedings ArticleDOI
01 Feb 1988
TL;DR: An experimental DC-to-DC converter prototype based on a zero-voltage switching, resonant circuit topology is described in this article, which is suitable for mounting directly on a circuit card.
Abstract: An experimental DC-to-DC converter prototype based on a zero-voltage switching, resonant circuit topology is described. The converter is suitable for mounting directly on a circuit card. The unit provides a regulated 5 V output at power levels up to 50 W with an input between 40 and 60 V. The switching frequency is between 20 and 24 MHz, depending on the input voltage and load. Differential input and output ripple and EMI are extremely low and somewhat difficult to measure. The converter prototype has been designed to demonstrate compatibility with a fully automated assembly process based on surface-mount technology. Solutions are presented to a number of problems, including MOSFET gate-drive and rectifier diode capacitance, that have seriously limited the performance of high-frequency converters operating with useful input and output voltages. >

85 citations


Journal ArticleDOI
TL;DR: In this article, an analysis of the phase-controlled DC-AC converter is presented, where a pair of switches in each side of the primary and the secondary of the isolation transformer are controlled by the phase difference between the two switches.
Abstract: An analysis of the phase-controlled DC-AC converter is presented. This converter has a pair of switches in each side of the primary and the secondary of the isolation transformer. The voltage conversion ratio is controlled by the phase difference between the two pairs of switches. The averaged equivalent circuit for low frequency operation is derived. The switching surge during commutation is much reduced by dividing the reactor into two parts. As a result, the transformer is miniaturized by increasing the switching frequency and the reactive energy can be easily recovered to the DC source. This DC-AC converter is especially suitable for small uninterruptible power supply systems. >

Patent
19 Apr 1988
TL;DR: In this paper, a high frequency DC to DC converter with at least two phase differentiated pulsed voltage sources, utilizes two-phase differentiated unidirectional power flow resonant circuits to permit multiple quasi resonant operation of the converter.
Abstract: A high frequency DC to DC converter (FIG. 1) having at least two phase differentiated pulsed voltage sources, utilizes two phase differentiated unidirectional power flow resonant circuits to permit multiple quasi resonant operation of the converter.

Proceedings ArticleDOI
Arai1, Baba
01 Jan 1988

PatentDOI
02 Mar 1988
TL;DR: In this article, a digital-to-analog converter (DAC) is proposed for converting a digital signal (DS) into an analog signal (UOUT) having a maximum voltage range which corresponds to a second supply voltage (UH).
Abstract: A digital to analog converter (DAC) for converting a digital signal (DS) having a maximum voltage range which corresponds to a first supply voltage (UL) into an analog signal (UOUT) having a maximum voltage range which corresponds to a second supply voltage (UH). The first supply voltage (UL) is offered between a first supply terminal (VSS) and a second supply terminal (VDDL). The second supply voltage (UH) is offered between the first supply terminal (VSS) and a third supply terminal (VDDH). The digital to analog converter (DAC) comprises conversion resistors (RCNV0 - RCNVn) and coupling means (CPL) for coupling a number of said conversion resistors (RCNV2 - RCNVn) in between the first supply terminal (VSS) and an output terminal (OUT), and for coupling the remainder of said conversion resistors (RCNV0 - RCNV1) in between the third supply terminal (VDDH) and the output terminal (OUT). The value of said number depends on the data content of the digital signal (DS). Digital to analog converters are generally implemented in ICs. For modern ICs there is a trend toward ever decreasing supply voltages. Often circuits implemented in new IC processes have to be able to interface with ICs processed in less modern processes which are generally operated on higher supply voltages. In the modern process, therefore, circuits designed in modern ICs have to cope with voltages which are above the maximum specification for their transistors or other components. The DA-converter (DAC) mentioned above fulfils this requirement by the fact that material, such as polycrystalline silicon, is used for the conversion resistors (RCNV2 - RCNVn), which material can cope with relatively high voltages, and furthermore by the fact that only the coupling means (CPL) have to be designed to cope with relatively high voltages.

Proceedings ArticleDOI
11 Apr 1988
TL;DR: A description is given of a resonant DC-DC converter that uses both the leakage inductances and stray winding capacitances of a high-voltage transformer as LC resonant components and the input capacitance of high- voltage cables as a smoothing DC capacitor.
Abstract: A description is given of a resonant DC-DC converter that uses both the leakage inductances and stray winding capacitances of a high-voltage transformer as LC resonant components and the input capacitance of high-voltage cables as a smoothing DC capacitor. The converter incorporates a pulsewidth-modulated (PWM) control based on a high-frequency inverter at constant frequency to adjust output over a wide range of loads, Its application to an X-ray generator power supply system is reported. A computer-aided state-variable analysis of the circuit is presented. Experimental results using a prototype transformer are given, covering output voltage control characteristics, maximum output power, and converter output waveforms in the X-ray generator. >

Proceedings ArticleDOI
G.B. Joung1, Chun T. Rim1, Gyu-Hyeong Cho1
02 Oct 1988
TL;DR: In this article, a buck/boost converter with an equivalent inductor is proposed for the operation of SRCs with boost and buck-boost characteristics, which can be designed to be controlled with advanced closed-loop feedback.
Abstract: Quantum series resonant converters (SRCs), a subset of SRCs operating on optimal conditions, are modeled. It is shown that this type of SRC can be modeled as a buck/boost converter with an equivalent inductor. Operation of SRCs with boost and buck-boost characteristics is proposed. Modeling of these converters is verified through analysis and simulation results. Using these models, the quantum SRCs can be designed to be controlled with advanced closed-loop feedback, with advantages such as low device switching stress, reliable high-frequency operation, and low EMI (electromagnetic interference). >

DissertationDOI
01 Jan 1988
TL;DR: In this article, a low-frequency dynamic model of a single-phase ac-dc power conversion system is presented, where the conversion ratio of a quasi-resonant dc-dc converter is derived in terms of the well-known PWM topology.
Abstract: Part I: Quasi-resonant converters are a family of single-switch resonant dc-dc converters featuring zero-current or zero-voltage switching. Recognition of the topological structure uniting these resonant converters--and the rectangular-wave (PWM) converters on which they are based--leads to general models of their dc and low-frequency ac behavior. An expression is derived that yields the dc conversion ratio of a quasi-resonant converter in terms of the well-known conversion ratio of the underlying PWM topology. A small-signal, low-frequency dynamic model is developed whose parameters also incorporate the PWM conversion ratio. The dc and ac models reveal that any quasi-resonant converter with a full-wave resonant switch has dc and low-frequency behavior identical to that of its PWM parent, with switching-frequency control replacing duty-ratio control. Converters with half-wave resonant switches behave more like PWM converters in discontinuous conduction mode or with current programming, exhibiting lossless damping in the small-signal model and output resistance at dc. Although quasi-resonant converters come in an astounding variety of topologies, the dc (and to a large extent ac) behavior of these converters depends only on the underlying PWM topology and the class of resonant switch, and is unchanged by movement of the resonant reactances to various alternative positions. Part 2: The distorted input-current waveforms of nonlinear electronic loads cause interference and lead to poor utilization of the utility power line, a situation that is rapidly becoming intolerable with the increased application of electronic loads. Input-current shaping, also known as power-factor improvement, addresses the problem of improving current waveforms drawn from the power line. This study is restricted to single-phase ac-dc power conversion systems. Current-shaping circuits are shown to fall into just a few categories with common features and limitations. In addition to the more common buck- and boost-based current-shaping converters, a class of circuits with "automatic" current shaping is presented and analyzed. A set of rules is derived for determining whether a particular dc-dc converter topology is suitable for use as a current-shaping ac-dc converter, and the rules are used to judge the suitability of several resonant converter topologies for this application. A new, low-cost converter is suggested that combines input-current shaping, isolation, and fast output-voltage regulation. Input-current shaping requires that a converter store significant energy, leading to unfortunate size and weight restrictions. Additional implications of stored energy are examined, along with several methods of reducing the energy storage. It is shown that the ability of a current-shaping converter to regulate its output voltage is severely restricted as a result of the energy requirement. The methods and implications of introducing isolation to a shaping ac-dc converter are also studied.

Journal ArticleDOI
TL;DR: In this paper, the authors verify the validity of applying state-space averaging and linearization to the control law of current-injected switching regulators for designs with wideband first-order open-loop responses without right-hand plane (RHP) zeros.
Abstract: The authors verify the validity of applying state-space averaging and linearization to the control law of current-injected switching regulators for designs with wideband first-order open-loop responses without right-hand plane (RHP) zeros. Quantitative closed-loop performance comparisons are made of current-injected versus voltage control for the boost and buck switching regulator topologies. In buck-topology regulators, current-injected control implemented using pole cancellation, does not yield categorically better closed-loop performance than what is obtained by using lead compensated voltage control. For the boost regulator, the advantages of current-injected control are greater since lead-compensation cannot usually be used due to the duty-factor-dependent complex pole and RHP zero. >

Patent
29 Sep 1988
TL;DR: In this paper, the load current of the power converter is detected and averaged, and it is added to the voltage control signal of the voltage controller system which controls the converter output voltage to be constant, so that the converter control is less affected by the ripple of the load currents.
Abstract: A control circuit for an a.c. to d.c. power converter, in which the load current of the power converter is detected and averaged, and it is added to the voltage control signal of the voltage control system which controls the converter output voltage to be constant, so that the converter control is less affected by the ripple of the load current.

Patent
11 Feb 1988
TL;DR: In this article, a control circuit for a 3-phase converter with an output filter provided with a current minor loop which controls an instantaneous value of output current on the basis of a feedback signal obtained by converting the output current of the converter to d axis and q axis components by a synchronous revolutional coordinate system and a voltage major loop that controls the instantaneous value for the output voltage.
Abstract: A control circuit for a 3-phase converter which is provided to control the 3-phase converter having an output filter provided with a current minor loop which controls an instantaneous value of the output current on the basis of a feedback signal obtained by converting the output current of the converter to d axis and q axis components by a synchronous revolutional coordinate system and a voltage major loop which controls the instantaneous value of the output voltage on the basis of a feedback signal obtained by converting the output voltage of the output filter to the d axis and q axis components; and realizes protection from overcurrent due to short-circuit of output.

Patent
15 Dec 1988
TL;DR: An electric arrangement for igniting and supplying a gas discharge lamp is described in this paper, where the lamp is connected to an alternating voltage source and comprises a rectifier bridge (7) connected to a DC/DC converter provided with a Rectifier element (11), a coil (10), and a high-frequency switched semiconductor switching element (12) coupled to a drive circuit.
Abstract: An electric arrangement for igniting and supplying a gas discharge lamp (1). The arrangement is connected to an alternating voltage source and comprises a rectifier bridge (7) connected to a DC/DC converter provided with a rectifier element (11), a coil (10) and a high-frequency switched semiconductor switching element (12) coupled to a drive circuit. The DC/DC converter is connected to the input terminals (16, 17) of a high-frequency DC/AC converter incorporating the lamp and provided with semiconductor switching elements (21,24). A capacitor (15) is arranged between the input terminals of the DC/AC converter and a sensor (22) for measuring the converter current is arranged between one of the input terminals (17) and a semiconductor switching element (21) of the DC/AC converter. The lamp is connected in series with a frequency-dependent impedance 20. A drive circuit (13) of the semiconductor switching element in the DC/DC converter is coupled to a control circuit (14) and is also coupled to the capacitor (15). The voltage across the capacitor (15) is set to a desired value by adjusting the frequency and the period of conductance of the semiconductor switching element (12). The sensor (22) is coupled to a second control circuit (27) which is connected to the drive circuits (21a, 24a) of the semiconductor switching elements (21, 24) of the DC/AC converter whereby the frequency and/or period of conductance of the switching elements of the DC/AC converter, and hence the power consumption of the lamp, can be regulated.

Patent
26 May 1988
TL;DR: A power supply system for a dynamic memory includes a main power supply, a backup power supply and a power down detection circuit which are all connected in parallel across the input of a DC/DC converter as discussed by the authors.
Abstract: A power supply system for a dynamic memory includes a main power supply, a backup power supply and a power down detection circuit which are all connected in parallel across the input of a DC/DC converter In turn the DC/DC converter supplies regulated power to the dynamic memory On interruption of the main power supply, the backup supply provides input power to the DC/DC converter only as long as the power sensed by the power down detection circuit is adequate for the DC/DC converter to maintain a bit pattern stored in the dynamic memory On sensing inadequate input power to the DC/DC converter the backup supply is automatically disconnected

Patent
12 Oct 1988
TL;DR: In this article, a four-quadrant buck converter is described with a common leg of an inductor in series with an output capacitor, one power supply for providing a positive voltage output signal and negative voltage output signals to two solid-state switches joined at a common node, an output transformer whose primary is connected across the output capacitor and a pulse width modulated control circuit for operating the switches to produce a predetermined voltage across said output capacitance and for regulating the current out of the transformer.
Abstract: A four-quadrant buck converter is described having a common leg of an inductor in series with an output capacitor, one power supply for providing a positive voltage output signal and negative voltage output signal to two solid-state switches joined at a common node, an output transformer whose primary is connected across the output capacitor and a pulse width modulated control circuit for operating the switches to produce a predetermined voltage across said output capacitor and for regulating the current out of the transformer. The control circuitry operates in response to a voltage signal from the output of the power supply, a voltage representative of the voltage at the output of the converter, a high frequency ramp voltage, an internal oscillator, and a voltage representative of the RMS current flowing on the secondary side of the output transformer. The converter incorporates overcurrent protection, an under-voltage lockout, overshoot protection, a slow start-up, inexpensive RMS conversion and other useful functions and capabilities.

Proceedings ArticleDOI
11 Apr 1988
TL;DR: In this article, the DC behavior of a clamped-mode, series-resonant converter is characterized systematically, given a circuit operating condition, the converter's model of operation is determined and various circuit parameters are calculated, such as average inductor current (load current), RMS inductor currents, peak capacitor voltage, RMS switch currents, average diode currents, switch turn on currents, and switch turn off currents.
Abstract: The DC behavior of a clamped-mode, series-resonant converter is characterized systematically. Given a circuit operating condition, the converter's model of operation is determined and various circuit parameters are calculated, such as average inductor current (load current), RMS inductor current, peak capacitor voltage, RMS switch currents, average diode currents, switch turn-on currents, and switch turn-off currents. Regions of operations are defined, and various circuit characteristics are defined to facilitate the converter design. >

Patent
27 Oct 1988
TL;DR: In this paper, a power factor correction circuit for an off-line supply of the switch mode type is described, where the inductor causes the amplitude of the unidirectional current to increase and decrease at a rate which is less than it would be if the inductors were not so connected.
Abstract: A power factor correction circuit for an off line supply of the switch mode type. In its simplest form the circuit is made up of a capacitor and an inductor. The capacitor is to be connected to the input rectifier of the supply. The capacitor is in aiding relationship for each half cycle of the line voltage. When so connected, a unidirectional current flows from the rectifier to charge the bank capacitors of the supply. The inductor is to be connected to at least the rectifier. The inductor causes the amplitude of the unidirectional current to increase and decrease at a rate which is less than it would be if the inductor was not so connected. Embodiments having at least two capacitors which are controlled to be switched in and out of the correction circuit as well as one or more inductors which may or may not be controlled are also disclosed.

Patent
10 May 1988
TL;DR: In this article, a power converter having a thyristor converter connected to an AC power source to rectify its AC output, a DC intermediate circuit including a smoothing capacitor and receiving a rectified output from the rectifier and a voltage type inverter for converting a DC voltage applied from the dc intermediate circuit into an AC output voltage of a variable voltage and a variable frequency.
Abstract: A power converter having a thyristor converter connected to an AC power source to rectify its AC output, a DC intermediate circuit including a smoothing capacitor and receiving a rectified output from the thyristor rectifier and a voltage type inverter for converting a DC voltage applied from the DC intermediate circuit into an AC output voltage of a variable voltage and a variable frequency. The DC intermediate circuit has two series circuits, each having a diode and a transistor switch, connected in parallel with each other and to the both terminals of the thyristor converter. The junctions, each between the diode and the resistor, are connected to the both terminals of the smoothing capacitor. The two series circuits function to switch the connection polarities of the thyristor converter and the smoothing capacitor and to regulate the voltage across the capacitor with a limited current by a voltage step-up or step-down operation by the transistor switch.

Proceedings ArticleDOI
H. Seidel1
11 Apr 1988
TL;DR: An approach for achieving high power factor in a zero-current/zero-voltage-switching tuned converter is presented in this article, where a tuned 90 degrees C phase shift section at the switching frequency fundamental of the Class D converter is used to render the power line into a current source.
Abstract: An approach for achieving high power factor in a zero-current/zero-voltage-switching tuned converter is presented. A tuned 90 degrees C phase shift section at the switching frequency fundamental of the Class D converter is used to render the power line into a current source. As a result, rectification occurs over the full AC cycle, drawing a constant line current over each half cycle. A 93%-power-factor, 1700 W, 300 kHz converter is discussed to demonstrate practicability. >

Journal ArticleDOI
TL;DR: In this paper, a clamped-mode parallel-resonant converter with a wide output voltage regulation range was proposed and analyzed using graphical state-plane techniques, and five circuit operating modes were identified and their mode boundaries defined.
Abstract: A novel clamped-mode parallel-resonant converter which operates at a constant frequency and provides a wide output voltage regulation range is proposed and analyzed. Employing graphical state-plane techniques, five circuit operating modes are identified and their mode boundaries defined. Regions for natural and forced commutation of power devices are specified. The DC control-to-output characteristics are derived to facilitate converter design. The predicted operating modes are experimentally verified using a 105 kHz prototype circuit. >

Proceedings ArticleDOI
Javier Sebastian, J. Uceda, M. Rico1, M.A. Perez, F. Aldana 
11 Apr 1988
TL;DR: In this article, a two-output DC-to-DC converter is studied using only a power transistor, and both outputs have been regulated by controlling duty cycle and switching frequency.
Abstract: A novel two-output DC-to-DC converter is studied. Using only a power transistor, both outputs have been regulated by controlling duty cycle and switching frequency. The number of power components is very low, as the use of demagnetizing components of the isolation transformer is avoided. A static and dynamic study of the converter has been carried out, and the results are verified for a prototype. >

Journal ArticleDOI
TL;DR: In this article, the performance of a three-phase converter is evaluated under both balance and unbalanced supply situations, and it is observed that the level of imbalance in the supply voltage increases the harmonic content of the input current and decreases the power factor of the converter.
Abstract: A three-phase converter is fully analyzed, and the performance of the converter is evaluated under both balance and unbalanced supply situations. It is observed that the level of imbalance in the supply voltage increases the harmonic content of the input current and decreases the power factor of the converter. This situation worsens toward the lower output region of the converter. The nature of the analysis has been kept very general so that future related work can be incorporated. >