Showing papers on "Rectifier published in 1998"

High efficiency power converter

Abstract: A power converter nearly losslessly delivers energy and recovers energy from capacitors associated with controlled rectifiers in a secondary winding circuit, each controlled rectifier having a parallel uncontrolled rectifier. First and second primary switches in series with first and second primary windings, respectively, are turned on for a fixed duty cycle, each for approximately one half of the switching cycle. Switched transition times are short relative to the on-state and off-state times of the controlled rectifiers. The control inputs to the controlled rectifiers are cross-coupled from opposite secondary transformer windings.

Control of a voltage-source converter connected to the grid through an LCL-filter-application to active filtering

Abstract: In this paper, a control principle for a voltage source converter connected to the grid through an LCL-filter is presented. The dynamic performance is compared with the performance obtained with an L-filter and a dead-beat vector control system. Measured frequency responses and an active filtering operation verify the control principle. By using an LCL-filter, high attenuation of harmonics caused by the PWM and high dynamic performance can be obtained simultaneously. Different methods for active filtering are compared. It is advantageous to use a Fourier-method since it allows for compensation for time delays occurring in the control system in the frequency domain. By using the LCL-filter along with compensation for time delays in the frequency domain, active filtering can be performed at moderate switching frequencies. This is a major advantage in systems, such as a rectifier with an active filtering option.

Introduction to modern power electronics

Abstract: Preface. 1 Principles and Methods of Electric PowerConversion. 1.1 What Is Power Electronics? 1.2 Generic Power Converter. 1.3 Waveform Components and Figures of Merit. 1.4 Phase Control. 1.5 Pulse Width Modulation. 1.6 Calculation of Current Waveforms. 1.6.1 Analytical Solution. 1.6.2 Numerical Solution. 1.6.3 Practical Examples: Single-Phase Diode Rectifiers. 1.7 Summary. Example. Problems. Computer Assignments. Literature. 2 Semiconductor Power Switches. 2.1 General Properties of Semiconductor Power Switches. 2.2 Power Diodes. 2.3 Semicontrolled Switches. 2.3.1 SCRs. 2.3.2 Triacs. 2.4 Fully Controlled Switches. 2.4.1 GTOs. 2.4.2 IGCTs. 2.4.3 Power BJTs. 2.4.4 Power MOSFETs. 2.4.5 IGBTs. 2.5 Comparison of Semiconductor Power Switches. 2.6 Power Modules. 2.7 Summary. Literature. 3 Supplementary Components and Systems. 3.1 What Are Supplementary Components and Systems? 3.2 Drivers. 3.2.1 Drivers for SCRs, Triacs, and BCTs. 3.2.2 Drivers for GTOs and IGCTs. 3.2.3 Drivers for BJTs. 3.2.4 Drivers for Power MOSFETs and IGBTs. 3.3 Overcurrent Protection Schemes. 3.4 Snubbers. 3.4.1 Snubbers for Power Diodes, SCRs, and Triacs. 3.4.2 Snubbers for GTOs and IGCTs. 3.4.3 Snubbers for Transistors. 3.4.4 Energy Recovery from Snubbers. 3.5 Filters. 3.6 Cooling. 3.7 Control. 3.8 Summary. Literature. 4 AC-to-DC Converters. 4.1 Diode Rectifiers. 4.1.1 Three-Pulse Diode Rectifier. 4.1.2 Six-Pulse Diode Rectifier. 4.2 Phase-Controlled Rectifiers. 4.2.1 Phase-Controlled Six-Pulse Rectifier. 4.2.2 Dual Converters. 4.3 PWM Rectifiers. 4.3.1 Impact of Input Filter. 4.3.2 Principles of Pulse Width Modulation. 4.3.3 Current-Type PWM Rectifier. 4.3.4 Voltage-Type PWM Rectifier. 4.4 Device Selection for Rectifiers. 4.5 Common Applications of Rectifiers. 4.6 Summary. Examples. Problems. Computer Assignments. Literature. 5 AC-to-AC Converters. 5.1 AC Voltage Controllers. 5.1.1 Phase-Controlled Single-Phase AC Voltage Controller. 5.1.2 Phase-Controlled Three-Phase AC Voltage Controllers. 5.1.3 PWM AC Voltage Controllers. 5.2 Cycloconverters. 5.3 Matrix Converters. 5.4 Device Selection for AC-to-AC Converters. 5.5 Common Applications of AC-to-AC Converters. 5.6 Summary. Examples. Problems. Computer Assignments. Literature. 6 DC-to-DC Converters. 6.1 Static DC Switches. 6.2 Step-Down Choppers. 6.2.1 First-Quadrant Chopper. 6.2.2 Second-Quadrant Chopper. 6.2.3 First-and-Second-Quadrant Chopper. 6.2.4 First-and-Fourth-Quadrant Chopper. 6.2.5 Four-Quadrant Chopper. 6.3 Step-Up Chopper. 6.4 Current Control in Choppers. 6.5 Device Selection for Choppers. 6.6 Common Applications of Choppers. 6.7 Summary. Example. Problems. Computer Assignments. Literature. 7 DC-to-AC Converters. 7.1 Voltage-Source Inverters. 7.1.1 Single-Phase Voltage-Source Inverter. 7.1.2 Three-Phase Voltage-Source Inverter. 7.1.3 Voltage Control Techniques for Voltage-SourceInverters. 7.1.4 Current Control Techniques for Voltage-SourceInverters. 7.2 Current-Source Inverters. 7.2.1 Three-Phase Square-Wave Current-Source Inverter. 7.2.2 Three-Phase PWM Current-Source Inverter. 7.3 Multilevel Inverters. 7.4 Soft-Switching Inverters. 7.5 Device Selection for Inverters. 7.6 Common Applications of Inverters. 7.7 Summary. Examples. Problems. Computer Assignments. Literature. 8 Switching Power Supplies. 8.1 Basic Types of Switching Power Supplies. 8.2 Nonisolated Switched-Mode DC-to-DC Converters. 8.2.1 Buck Converter. 8.2.2 Boost Converter. 8.2.3 Buck Boost Converter. 8.2.4 uk Converter. 8.2.5 SEPIC and Zeta Converters. 8.2.6 Comparison of Nonisolated Switched-Mode DC-to-DCConverters. 8.3 Isolated Switched-Mode DC-to-DC Converters. 8.3.1 Single-Switch Isolated DC-to-DC Converters. 8.3.2 Multiple-Switch Isolated DC-to-DC Converters. 8.3.3 Comparison of Isolated Switched-Mode DC-to-DCConverters. 8.4 Resonant DC-to-DC Converters. 8.4.1 Quasi-Resonant Converters. 8.4.2 Load-Resonant Converters. 8.4.3 Comparison of Resonant DC-to-DC Converters. 8.5 Summary. Examples. Problems. Computer Assignments. Literature. 9 Power Electronics and Clean Energy. 9.1 Why Is Power Electronics Indispensable in Clean EnergySystems? 9.2 Solar and Wind Renewable Energy Systems. 9.2.1 Solar Energy Systems. 9.2.2 Wind Energy Systems. 9.3 Fuel Cell Energy Systems. 9.4 Electric and Hybrid Cars. 9.5 Power Electronics and Energy Conservation. 9.6 Summary. Literature. Appendix A PSpice Simulations. Appendix B Fourier Series. Appendix C Three-Phase Systems. Index.

A four level rectifier inverter system for drive applications

Abstract: In a motor drive, the converters must be able to handle bidirectional real power flow. So far, DC voltage balancing has not been satisfactorily discussed for the case when real power is drawn from the inverter. This article addresses the control issues involved in a four-level inverter based AC drive application. The DC capacitor voltages are balanced for both motoring and regenerating modes of the inverter-motor system. In addition, DC voltages can be balanced even during motor startup with the associated large overcurrents.

Uncontrolled generator operation of interior PM synchronous machines following high-speed inverter shutdown

Abstract: Interior permanent magnet (IPM) synchronous machine drives are vulnerable to a special fault mode when gating is suddenly removed from the inverter switches during high-speed operation. The resulting IPM machine operation as a generator in combination with an uncontrolled rectifier must be properly understood and accounted for in the machine design to avoid damage to either the machine or inverter. An approximate closed-form solution is derived in this paper which relates the resulting machine phase current (and torque) to the IPM machine parameters, the DC-link voltage and the rotor speed. The resulting operating characteristics are particularly interesting for IPM machines that have been designed with inductance saliency ratios greater than 2 (i.e., high-saliency machines). The validity of the approximate solution is confirmed using dynamic simulation results, and the implications of these results for the machine designer seeking to minimize or eliminate the impact of this undesired operating mode are thoroughly discussed.

Disk drive utilizing Bemf of spindle motor to increase VCM voltage during seeks

Abstract: A disk drive is connectable to a power supply having a fixed DC voltage The disk drive includes a voice coil motor (VCM) and a spindle motor having a plurality of windings and a rotor rotatable at a variable spin-rate A spindle motor driver is coupled to the fixed DC voltage and at least one of the windings for controlling the spin-rate of the rotor The rotor has permanent magnets that induce an AC voltage across the windings while the rotor is rotating A rectifier circuit rectifies the AC voltage across at least one of the windings to produce a rectified DC voltage A first switch provides the rectified DC voltage to a first node A second switch provides the fixed DC voltage to the first node The first node has a first node DC voltage that is determined by the rectified DC voltage provided by the first switch and the fixed DC voltage provided by the second switch The first node DC voltage is greater than the fixed DC voltage during a track seeking operation in the disk drive A VCM driver includes switching elements that selectively provide the first node DC voltage to the VCM The increased VCM voltage allows faster access times and more efficient VCM operation

Analysis and design for RCD clamped snubber used in output rectifier of phase-shift full-bridge ZVS converters

Abstract: Detailed analysis and parameter design for a resistor-capacitor-diode (RCD) clamped snubber used in the output rectifier of phase-shift full-bridge zero-voltage-switching (PS-FB-ZVS) power converters are presented. Design equations and some properties of the clamped circuit are also highlighted.

Turbogenerator/motor controller

Abstract: A turbogenerator/motor controller with a microprocessor based inverter having multiple modes of operation. To start the turbine, the inverter connects to and supplies fixed current, variable voltage, variable frequency, AC power to the permanent magnet turbogenerator/motor, driving the permanent magnet turbogenerator/motor as a motor to accelerate the gas turbine. During this acceleration, spark and fuel are introduced in the correct sequence, and self-sustaining gas turbine operating conditions are reached. The inverter is then disconnected from the permanent magnet generator/motor, reconfigured to a controlled 60 hertz mode, and then either supplies regulated 60 hertz three phase voltage to a stand alone load or phase locks to the utility, or to other like controllers, to operate as a supplement to the utility. In this mode of operation, the power for the inverter is derived from the permanent magnet generator/motor via high frequency rectifier bridges. The microprocessor monitors turbine conditions and controls fuel flow to the gas turbine combustor.

Conduction power loss in MOSFET synchronous rectifier with parallel-connected Schottky barrier diode

Abstract: The conduction power loss in an MOSFET synchronous rectifier with a parallel-connected Schottky barrier diode (SBD) was investigated. It was found that the parasitic inductance between the MOSFET and SBD has a large effect on the conduction power loss. This parasitic inductance creates a current that is shared by the two devices for a certain period and increases the conduction power loss. If conventional devices are used for under 1 MHz switching, the advantage of the low on-resistance MOSFET will almost be lost. To reduce the conduction loss for 10 MHz switching, the parasitic inductance must be a subnanohenley.

Schottky diode with dielectric trench

Abstract: An improved diode or rectifier structure and method of fabrication is disclosed involving the incorporation in a Schottky rectifier, or the like, of a dielectric filled isolation trench structure formed in the epitaxial layer adjacent the field oxide layers provided at the edge of the active area of the rectifier, for acting to enhance the field plate for termination of the electric field generated by the device during operation. The trench is formed in a closed configuration about the drift region and by more effectively terminating the electric field at the edge of the drift region the field is better concentrated within the drift region and acts to better interrupt reverse current flow and particularly restricts leakage current at the edges.

Use of traction inverter for supplying power for non-traction applications

Abstract: A method and apparatus for cranking of an internal combustion engine in an AC electric traction motor propelled vehicle using inverters normally coupled to supply power to each of a plurality of AC motors The inverters have DC input terminals connected between a relatively positive DC bus and a relatively negative DC bus and the DC buses are connected to DC output terminals of a rectifier The rectifier has AC input terminals connected to stator terminals of a synchronous generator The generator includes a field winding and a rotor connected in driving relationship to a crank shaft of the engine The vehicle further includes switching apparatus for selectively connecting a battery to the positive and negative DC buses and for disconnecting at least one of the inverters from the AC motor and connecting the at least one of the inverters to supply power to the generator such that the at least one of the inverters is operable to energize the generator whereby the generator operates in a motoring mode to rotate the engine crank shaft to start the engine Another of the inverters is separately connectable to a pre-lube pump motor for effecting lubrication of the engine prior to starting the engine After lubricating and starting of the engine, the switch reconnects the inverters to supply AC electric power to respective traction motors of the vehicle

Novel zero-voltage and zero-current-switching (ZVZCS) full bridge PWM converter using a simple auxiliary circuit

Abstract: A novel zero voltage and zero current switching (ZVZCS) full bridge (FB) PWM power converter is presented to simplify the circuits of the previously presented ZVSCS power converters. A simple auxiliary circuit which consists of one small capacitor and two small diodes is added in the secondary to provide ZVZCS conditions to primary switches as well as to clamp secondary rectifier voltage. The additional clamp circuit for the secondary rectifier is not necessary. The auxiliary circuit includes neither lossy components nor additional active switches which makes the proposed power converter efficient and cost effective. The principle of operation, features and design considerations are illustrated and verified on a 2.5 kW, 100 kHz IGBT-based experimental circuit.

DC power supply apparatus

Abstract: DC power supply apparatus includes an input-side rectifier for converting an AC signal from an AC power supply into a DC signal. A DC-to-high-frequency converter converts the DC signal into a high frequency signal in response to a control signal from a control unit. An output-side rectifier converts the high frequency signal into a DC signal and applies it to a load. An input current detector detects an input current flowing through the input-side rectifier and generates a signal representative of the input current. A load current detector detects a load current flowing through the load and generates a signal representative of the load current. The control unit receives the input-current and load-current representative signals, a reference input current signal and a reference load current signal, and provides the DC-to-high-frequency converter with the control signal such that the input-current representative signal can be equal to the reference input current signal and the load-current representative signal can be equal to the reference load current signal.

Electric arc welder and plasma cutter

Abstract: A single phase power supply module for electric arc welders and plasma arc cutters comprising: a single phase input stage; positive and negative output terminals; a full wave rectifier connected to the input stage for rectifying the single phase voltage at the input stage; a buck converter type power factor correcting circuit for controlling current flow from the input stage to the rectifier, which buck converter has an output capacitor regulated to an intermediate voltage in the range of 100-150 volts; and, a high speed DC to DC converter having an internal transformer coupling applying voltage across the output terminals and means for regulating the applied voltage to an output voltage in the range of 0-113 volts. The module is universal and several can be connected in parallel, in series or to switch networks to construct several welders or cutters.

Modeling and analysis of static and dynamic characteristics for buck-type three-phase PWM rectifier by circuit DQ transformation

Abstract: The static and dynamic characteristics of buck-type three-phase pulse width modulation (PWM) rectifier are fully analyzed based on the DC and AC circuit models developed by the circuit DQ transformation. Various static power converter characteristics such as gain, real and reactive power, power factor and unity power factor conditions are completely analyzed. Transition characteristics are also analyzed by both exact small-signal models with full set of equations and simplified output models in explicit form. The usefulness of the models is verified through computer simulations and experiments with good agreement shown.

Optimal current programming in three-phase high-power-factor rectifier based on two boost converters

Abstract: Current programming in a three-phase high-power-factor rectifier based on two boost converters is discussed in this paper. It is shown that the converter currents can be expressed in terms of two mutually related auxiliary functions. The auxiliary functions are related to the input current spectrum. Optimal auxiliary functions that eliminate harmonics of the input currents are derived. A method to generate reference signals for the optimal current programming is proposed. Experimental results confirming the proposed concepts are presented.

New single-switch three-phase high-power-factor rectifiers using multiresonant zero-current switching

Abstract: A new family of single-switch three-phase high-power-factor rectifiers, which have continuous input and output currents, is introduced. By using a multiresonant scheme, the transistor operates with zero-current switching (ZCS), and the diodes operate with zero-voltage switching (ZVS). These multiresonant rectifiers with a single transistor are capable of drawing a higher quality input-current waveform at nearly unity power factor and lower stresses than quasi-resonant rectifiers. Buck-type converters are used for the power stage, and, hence, the output voltage is lower than the input voltage. Moreover, these rectifiers have a wide load range and low stresses on semiconductor devices. From the analysis, normalized characteristics of the rectifier are derived. The design and breadboard implementation of the rectifier delivering 147 V/sub dc/ at 6 kW from a 3/spl phi/ 240-V/sub rms(LL)/ input is described. The total harmonic distortion (THD) of the line current is less than 5%, and the system efficiency is about 94% at the full load.

Two-stage, three phase boost converter with reduced total harmonic distortion

Abstract: For use with a three-phase split boost converter having a primary stage with a primary rectifier and first and second primary boost switches coupled between an input and first and second outputs of the three-phase split boost converter, an auxiliary stage interposed between the input and the first and second outputs, a method of reducing input current total harmonic distortion (THD) and a converter incorporating the auxiliary stage or the method. In one embodiment, the auxiliary stage includes: (1) first, second and third auxiliary boost inductors coupled to corresponding phases of the input and (2) an auxiliary boost network interposed between the first, second and third auxiliary boost inductors and the first and second outputs and including (2a) an auxiliary three phase full-wave rectifier, (2b) first and second auxiliary boost diodes, and (2c) first and second auxiliary boost switches, coupled between the auxiliary three phase full-wave rectifier and the first and second auxiliary boost diodes, that cooperate to conduct currents through the first, second and third auxiliary boost inductors to reduce input current total harmonic distortion (THD) at the input of the three-phase split boost converter.

Soft strat bridge rectifier circuit

Abstract: A soft start bridge rectifier circuit is described for controlling the operation of the bridge rectifier in order to ramp up the DC output upon connection with the AC input in order to limit in-rush current Additionally, short-circuit/overload protection, temporary line loss protection and undervoltage checking circuitry is provided

Power supply circuit

Abstract: not available for EP0927452Abstract of corresponding document: US5740026A power conditioning circuit for use in a power supply includes a power input and a power output The circuit also includes a series connected RFI-EMI filter, rectifier, and SCR between the power input and the power output The SCR has a control input for switching the SCR on and off, thereby interrupting current flow between the power input and the power output An energy storage circuit is connected across the power output Furthermore, the circuit includes a control circuit coupled to the control input of the SCR for switching the SCR on and off to maintain a regulated voltage at said power output in response to an AC input A conditioned DC output is produced in response to a DC input

Transistorized rectifier for a multiple output converter

Abstract: A secondary subcircuit of a converter circuit is disclosed where a method and circuit for operating a transistor to prevent reverse conduction of the current in the secondary subcircuit is disclosed. The diode in the secondary subcircuits of the prior art is replaced by a transistor and the circuitry for controlling the transistor is made part of the control circuit (ASIC). The secondary converter subcircuit includes a secondary coil for generating a voltage that passes through a first transistor M1, a capacitor, and a second transistor M2, where the output terminal of the subcircuit is across said capacitor. A presently preferred embodiment of a control circuit detects the voltage level at a sync node and the output voltage level at the output terminal and controls transistors M1 and M2 accordingly in generating the desired voltage level at the output terminal.

A technique for reducing rectifier reverse-recovery-related losses in high-power boost converters

Abstract: A circuit technique that reduces the boost power converter losses caused by the reverse-recovery current of the rectifier is described. The losses are reduced by inserting an inductor in the series path of the boost switch and a rectifier to control the di/dt rate of the rectifier during its turn off. The energy from the inductor after the boost switch turn off is returned to the input or delivered to the output via an active snubber.

Post regulator with energy recovery snubber and power supply employing the same

Abstract: For use with a post regulator for a power converter, the post regulator having a rectifier circuit and an output circuit, an energy recovery snubber, a method of operating the same and a power converter employing the snubber or the method. In one embodiment, the snubber includes: (1) a clamping diode and a clamping capacitor, series-coupled between the rectifier circuit and the output circuit, that cooperate to recover reverse recovery energy developed in the power converter to an output thereof and (2) a charge balancing circuit, coupled to the clamping capacitor, that maintains a charge balance of the clamping capacitor.

Single-stage single-switch input-current-shaping technique with fast-output-voltage regulation

Abstract: A new single-stage single-switch input-current-shaping (S/sup 4/ICS) technique, which combines the boost-like input-current shaper with a continuous-conduction-mode (CCM) DC/DC output stage, is described. In this technique, the boost inductor can operate in both the discontinuous conduction mode (DCM) and CCM. Due to the ability to keep a relatively low voltage (<450 V/sub DC/) on the energy-storage capacitor, this technique is suitable for the universal line-voltage applications. The voltage on the energy-storage capacitor is kept within the desirable range by the addition of two transformer windings. The principle of operation of the S/sup 4/ICS circuit with a forward DC/DC converter is presented. Experimental results obtained on a 100 W (5 V/20 A) prototype circuit are also given.

A comparative study of single-switch, three-phase, high-power-factor rectifiers

Abstract: Three three-phase, single-switch, high-power-factor rectifier implementations were evaluated on a comparative basis. Specifically, the discontinuous-conduction-mode boost rectifier with a 5/sup th/-harmonic-trap filter, the discontinuous-conduction-mode boost rectifier with a harmonic-injection circuit, and the multi-resonant, zero-current-switching buck rectifier were compared with respect to their efficiencies, compliance with the IEC555-2 specifications, volumes, weights, and costs. The comparisons were done for the three-phase, line-to-line input voltage of 380 V/sub rms//spl plusmn/20% and for 0-6 kW output-power range.

A comparative study of single-switch three-phase high-power-factor rectifiers

Abstract: Three three-phase single-switch high-power-factor rectifier implementations were evaluated on a comparative basis. Specifically, the discontinuous-conduction-mode (DCM) boost rectifier with a 5th-harmonic-trap filter, the DCM boost rectifier with a harmonic-injection circuit, and the multiresonant, zero-current-switching buck rectifier were compared with respect to their efficiencies, compliance with the IEC555-2 specifications, volumes, weights and costs. The comparisons were done for the three-phase line-to-line input voltage of 380 V/sub rms//spl plusmn/20% and for 0-6 kW output power range.

Neutral-point inverter

Abstract: A commercial power supply is connected to a rectifier (DB) through a low-pass filter (LPF). A smoothing capacitor (Cs), a series circuit of voltage dividing capacitors (C1, C2) and a series circuit of switching elements (Q1, Q2) are connected in parallel to the output of the rectifier (DB). Diodes (D1, D2) are connected in inverse-parallel to the respective switching elements (Q1, Q2), and a driving circuit (DR) is connected to the switching elements (Q1, Q2). A load circuit (R) consisting of a parallel circuit of an inductor (Lo), a fluorescent lamp (LT) and a resonance capacitor (C4) is connected between the node between the voltage dividing capacitors (C1, C2) and the node between the switching elements (Q1, Q2). By turning on/off the switching elements (Q1, Q2), the inductor (Lo) is operated as a step-up inverter to generate a stable high frequency high voltage across the inductor (Lo). Thus, a neutral-point inverter which generates a high frequency higher voltage with little 'waving' is provided.

Non-contact ic card

Abstract: PROBLEM TO BE SOLVED: To enable stable operation based on power supply due to electromagnetic induction by switching the operation of an IC card and the charging of a secondary battery with excess power, and the operation of an IC module with the secondary battery corresponding to the voltage of supplied power. SOLUTION: When an IC module 105 is turned into active state, a voltage is induced between the terminals of an antenna coil 102, rectified by a rectifier circuit 204b and made into power of a prescribed voltage. By periodically executing a voltage monitoring program 213a through a CPU 210, the voltage of power rectified by the rectifier circuit 204b is compared with an IC card driving enable voltage value. When the rectified voltage value is higher than the IC card driving enable voltage, power is supplied from the antenna coil 102 through a regulator 204c to an IC card controller and when the voltage value is further higher than a specified voltage, charging processing is simultaneously performed. When the voltage value is lower than the IC card driving enable voltage, a supply power switching circuit 204e is controlled and processing is switched to power supply from a secondary battery 104 through a charging/discharging control circuit 203.