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Showing papers on "Precision rectifier published in 2008"


Journal ArticleDOI
TL;DR: A new phase-shifted full-bridge converter with a voltage-doubler-type rectifier for a high-efficiency power-sustaining module of a plasma display panel that features simpler structure, lower cost, smaller mass, and lighter weight is proposed.
Abstract: A new phase-shifted full-bridge converter with a voltage-doubler-type rectifier for a high-efficiency power-sustaining module of a plasma display panel is proposed in this paper. The proposed converter employs a voltage-doubler rectifier without an output inductor. Since it does not have an output inductor, the voltage stresses of the rectifier diodes can be clamped at the output voltage level. Thus, since no dissipative resistor-capacitor snubber for rectifier diodes is needed, high-efficiency low-noise output voltage can be realized. Due to the elimination of the large output inductor, it features simpler structure, lower cost, smaller mass, and lighter weight. Furthermore, the proposed converter has wide zero-voltage-switching ranges of lagging leg switches with low current stresses of the primary power switches by using the magnetizing current. In addition, the resonance between the leakage inductor of the transformer and the rectifier capacitors can reduce the current stresses of the rectifier diodes and conduction losses. In this paper, the operational principles, analysis, design considerations, and experimental results are presented.

124 citations


Journal ArticleDOI
TL;DR: In this paper, a fully CMOS integrated active AC/DC converter for energy harvesting applications is presented, where the rectifier is realized in a standard 0.35 µm CMOS process without special process options.
Abstract: In this paper, a fully CMOS integrated active AC/DC converter for energy harvesting applications is presented. The rectifier is realized in a standard 0.35 µm CMOS process without special process options. It works as a full wave rectifier and can be separated into two stages—one passive and one active. The active part is powered from the storage capacitor and consumes about 600 nA at 2 V supply. The input voltage amplitude range is between 1.25 and 3.75 V, and the operating frequency range is from 1 Hz to as much as several 100 kHz. The series voltage drop over the rectifier is less than 20 mV. Measurements in combination with an electromagnetic harvester show a significant increase in the achievable output voltage and power compared to a common, discrete Schottky diode rectifier. The measured efficiency of the rectifier is over 95%. Measurements show a negligible temperature influence on the output voltage between −40 °C and +125 °C.

97 citations


Journal ArticleDOI
TL;DR: A low-cost diagnostic method for MOSFET faults in a zero- voltage-switching dc-dc converter is proposed that utilizes the dc-link current patterns as the signatures of faults of MOSfETs.
Abstract: The dc-dc converter is a critical component in a hybrid electric vehicle since it supplies power to an electronic control unit, as well as chassis electric components such as power windows, wipers, etc. In this paper, a low-cost diagnostic method for MOSFET faults in a zero- voltage-switching dc-dc converter is proposed. The proposed method utilizes the dc-link current patterns as the signatures of faults of MOSFETs. A presignal processing circuit consists of a peak detector and an integrator circuit. The ratio of peak-to-integral values, which is similar to the crest factor, is useful for diagnosis.

86 citations


Journal ArticleDOI
TL;DR: The new rectifier eliminates the need for additional large switches for load modulation and provides more flexibility in choosing the most appropriate load shift keying (LSK) mechanism through shorting and/or opening the transponder coil for any certain application.
Abstract: This paper describes the design and implementation of an integrated full-wave standard CMOS rectifier with built-in passive back telemetry mechanism for radio frequency identification (RFID) and implantable biomedical device applications. The new rectifier eliminates the need for additional large switches for load modulation and provides more flexibility in choosing the most appropriate load shift keying (LSK) mechanism through shorting and/or opening the transponder coil for any certain application. The results are a more robust back telemetry link, improved read range, higher back telemetry data rate, reduced rectifier dropout voltage, and saving in chip area compared to the traditional topologies. A prototype version of the new rectifier is implemented in the AMI 0.5- mum n-well 3-metal 2-poly 5 V standard CMOS process, occupying ~ 0.25 mm2 of chip area. The prototype rectifier was powered through a wireless inductive link and proved to be fully functional in its three modes of operation: rectification, open coil (OC), and short coil (SC).

86 citations


Journal ArticleDOI
TL;DR: In this article, a bridgeless dual-boost rectifier with reduced diode reverse-recovery problems is proposed for power-factor correction (PFC), where the body diodes of the power switches are utilised as output diiodes.
Abstract: A bridgeless dual-boost rectifier with reduced diode reverse-recovery problems is proposed for power-factor correction (PFC). In the proposed rectifier, conduction losses are lowered by essentially eliminating the full-bridge diode rectifier. The body diodes of the power switches are utilised as output diodes. A coupled inductor is designed to reduce the reverse-recovery problems of the body diodes. Zero-current switching is realised when the body diodes are turned off. In addition, for the use of this topology in a practical design, a control strategy is suggested by employing the linear peak current mode (LPCM) control. The LPCM control is implemented on leading-edge modulation, providing an efficient control scheme to obtain a high power-factor. The proposed rectifier is investigated theoretically and its design considerations are provided in detail. Finally, the experimental results based on a 500 W prototype are discussed to evaluate the performance of the proposed rectifier for a PFC circuit.

77 citations


Patent
Isaac Cohen1
31 Jul 2008
TL;DR: In this article, the use of a current emulator provides an inexpensive solution for controlling synchronous rectifier transitions without resorting to more expensive current sensing solutions that are commercially impracticable.
Abstract: A synchronous rectifier is switched in accordance with a primary switch transition and a reference signal representing current in a current storage device to which the synchronous rectifier is coupled. A current emulator provides a signal representing current in the current storage device as a volt-second product so that current stored in the current storage device while the primary switch is on is discharged by the synchronous rectifier. The use of a current emulator provides an inexpensive solution for controlling synchronous rectifier transitions without resorting to more expensive current sensing solutions that are commercially impracticable. Blanking intervals are provided for avoiding false transitions of the synchronous rectifier when the primary switch turns on and after the synchronous rectifier turns off. The disclosed system and method can be applied to flyback converters for a synchronous rectifier on the secondary side of a transformer, or the inductor of buck converters.

74 citations


Journal ArticleDOI
TL;DR: In this paper, a time domain method is presented to analyze the three phase rectifier with capacitor output filter, and an analytical Jacobian of the mismatch equations is obtained to ensure a quadratic convergence rate for the iteration process.
Abstract: This paper presents a time domain method to analyze the three phase rectifier with capacitor output filter. As demonstrated in the paper, the proposed method analytically evaluates harmonics, and obtains exact switching functions by iteratively solving for the switching instants. An analytical Jacobian of the mismatch equations is obtained to ensure a quadratic convergence rate for the iteration process. It is also demonstrated that a unified approach exists to analyze converters operating in the continuous conduction mode and discontinuous conduction mode. One potential application of the proposed model is to incorporate it into a harmonic power flow program to yield improved accuracy.

74 citations


Journal ArticleDOI
TL;DR: In this article, an integrated organic double half-wave rectifier for use in organic radio frequency identification (RFID) tags was demonstrated, which comprises two organic Schottky diodes, each followed by a capacitor, integrated on the same foil.
Abstract: We demonstrate an integrated organic double half-wave rectifier for use in organic radio frequency identification (RFID) tags This rectifier comprises two organic Schottky diodes, each followed by a capacitor, integrated on the same foil This rectifier delivers approximately twice the dc voltage of single half-wave rectifiers Its offset voltage is merely 2 V It is able to generate voltages of 10–14 V, which are necessary for driving current organic RFID multibit code generators, from an ac-input voltage of only 8–10 V amplitude, which are generated at rf magnetic fields of 09–13 A/m Such fields are below the minimum required rf magnetic field strength set by standards

73 citations


Journal ArticleDOI
TL;DR: The proposed buck-boost-type unity power factor rectifier can perform input power factor correction (PFC) over a wider voltage conversion range and is well suited for universal offline PFC applications for a low power range (<150 W).
Abstract: A buck-boost-type unity power factor rectifier is proposed in this paper. The main advantage of the proposed rectifier over the conventional buck-boost type is that it can perform input power factor correction (PFC) over a wider voltage conversion range. With a single switch, a fast well-regulated output voltage is achieved with a zero-current switch at turn-on. Moreover, the switch voltage stress is independent of converter load variation. The proposed converter is well suited for universal offline PFC applications for a low power range (<150 W ). The feasibility of the converter is confirmed with results obtained from a computer simulation and from an experimental prototype.

69 citations


Journal ArticleDOI
TL;DR: In this paper, a voltage-mode full-wave rectifier with high-input impedance using a dual-X second-generation current conveyor and three enhancement-type n-channel metal-oxide semiconductor field effect transistors (MOSFETs) is introduced.
Abstract: In this study, a novel voltage-mode full-wave rectifier with high-input impedance using a dual-X second-generation current conveyor and three enhancement-type n-channel metal-oxide semiconductor field-effect transistors (MOSFETs) is introduced. The proposed circuit does not employ any passive elements, and is simulated using SPICE program with level 49, 0.25 µm TSMC CMOS technology parameters to confirm the theory and exhibit the performance of the circuit.

66 citations


Journal ArticleDOI
TL;DR: An active rectifier with high power conversion efficiency (PCE) implemented in a 0.5- mum 5 V standard CMOS technology with two modes of built-in back telemetry; short- and open-circuit.
Abstract: In this paper, we present an active rectifier with high power conversion efficiency (PCE) implemented in a 0.5- mum 5 V standard CMOS technology with two modes of built-in back telemetry; short- and open-circuit. As a rectifier, it ensures a PCE > 80%, taking advantage of active synchronous rectification technique in the frequency range of 0.125-1 MHz. The built-in complementary back telemetry feature can be utilized in implantable microelectronic devices (IMD), wireless sensors, and radio frequency identification (RFID) applications to reduce the silicon area, increase the data rate, and improve the reading range and robustness in load shift keying (LSK).

Patent
07 Mar 2008
TL;DR: A three-pin integrated synchronous rectifier as discussed by the authors uses a control pin to receive a control signal used as a power bias voltage and a synchronous pulse to make the synchronous system operate normally.
Abstract: A three-pin integrated synchronous rectifier is the synchronous rectifier chip where the quantity of connection pins is the smallest possible quantity. The three-pin integrated synchronous rectifier uses a control pin to receive a control signal used as a power bias voltage and a synchronous pulse to make the synchronous rectifier chip operate normally. The control signal is obtained from the output pin of an auxiliary winding via a diode. The other pins are respectively the drain pin and the source pin of an internal power transistor and are connected with the output winding and the voltage output terminal for transmitting the power of the transformer to supply current for the loading.

Proceedings ArticleDOI
12 Dec 2008
TL;DR: In this paper, a high efficiency differential CMOS rectifier circuit for UHF RFID was developed, which has a cross-coupled bridge configuration and is driven by a differential RF input.
Abstract: A high efficiency differential CMOS rectifier circuit for UHF RFIDs was developed. The rectifier has a cross-coupled bridge configuration and is driven by a differential RF input. Differential-drive topology enables simultaneous low ON-resistance and small reverse leakage of diode-connected MOS transistors, resulting in large power conversion efficiency(PCE), especially under small RF input power conditions. The differential-drive rectifier was fabricated with 0.18-mum CMOS technology, and the measured performance was compared with those of other types of rectifiers. Dependence of the PCE on an input RF signal frequency and output loading conditions was also evaluated. 66% of PCE was achieved under conditions of 953 MHz, -12 dBm RF input and 10 KOmega DC output load. This is twice as large as that of the state-of-the-art rectifier circuit. The peak PCE increases with a decrease in operation frequency and with an increase in output load resistance.

Journal ArticleDOI
TL;DR: In this paper, a novel energy recovery clamp circuit is proposed to overcome the voltage overshoot and oscillation problem caused by interaction between junction capacitance of the rectifier diode and leakage inductance of the transformer.
Abstract: A full-bridge DC-DC converter employing a diode rectifier in the output experiences a severe voltage overshoot and oscillation problem across the diode rectifier caused by interaction between junction capacitance of the rectifier diode and leakage inductance of the transformer. The pronounced reverse-recovery current of high-power diodes significantly contributes to these issues by increasing power lossand voltage overshoot. Conventional energy recovery clamping circuits suffer from high voltage overshoot if the converter input voltage is wide. In this paper, a novel energy recovery clamp circuit is proposed to overcome this problem. The proposed circuit requires neither active switches nor lossy components. Therefore, the proposed circuit is very promising in high-voltage and high-power applications. Performance of the proposed circuit is verified both theoretically and experimentally with a 70-kW DC-DC converter.

Patent
16 May 2008
TL;DR: In this article, an adjustable compensation offset voltage is applied to a comparator to vary the turn-off timing of a synchronous rectifier, which improves the accuracy of the rectifier turnoff in relation to a zero inductor current.
Abstract: An adjustable compensation offset voltage is applied to a comparator to vary turn-off timing of a synchronous rectifier. A comparator output indicates when current through an inductor coupled to the synchronous rectifier should be approaching zero. If the synchronous rectifier is turned off before the current through the inductor reaches zero, the compensation offset voltage (402) is adjusted to delay the synchronous rectifier turn-off for the next switching cycle. If the synchronous rectifier is turned off after the current through the inductor reaches zero, the compensation offset voltage is adjusted to advance the synchronous rectifier turn-off for the next switching cycle. An up/down counter (412), in conjunction with a digital to analog converter, may be used to provide the adjustment to the compensation offset voltage. The adjustable compensation offset voltage improves the accuracy of synchronous rectifier turn-off in relation to a zero inductor current, thereby improving power converter efficiency.

Journal ArticleDOI
TL;DR: In this article, a three-phase rectifier with a new connection is presented, where the use of the Scott transformer makes a split DC-bus voltage possible and the rectifier operates with unity power factor.
Abstract: In this work, the three-phase rectifier with a new connection is presented. The use of the Scott transformer makes a split DC-bus voltage possible and the rectifier operates with unity power factor. Using only two active switches, the rectifier is able to generate symmetrical currents in the line and a balanced split DC-bus output voltage, which is necessary in several applications. Pulse width modulation and instantaneous average current control are used. There are two voltage controls that regulate the output voltage and the split DC-bus voltage. Complete simulation results under closed loop operation are given, as well as results of an experimental setup.

Journal ArticleDOI
TL;DR: The proposed current-limit algorithm of the inverter can be implemented without additional hardware, and it increases the reliability of the UPS.
Abstract: A high-performance three- to single-phase online uninterruptible power supply (UPS) is proposed. The proposed UPS is composed of a rectifier, a battery charger/discharger, and an inverter. The rectifier has the capability of power-factor correction and regulates a DC-link voltage. When the rectifier becomes unavailable or when the current required by the load exceeds the output rating of the rectifier, the charger/discharger supplies the power demanded by the load to a DC-link capacitor. The inverter provides a regulated sinusoidal output voltage and limits an output current under an impulsive load. New control algorithms of the rectifier, the charger/discharger, and the inverter are proposed. The proposed algorithms of the rectifier and the charger/discharger improve dynamic performance at step load change. To improve the transient response of the output voltage at outage of an input source, a mode change method of the charger/discharger is also proposed. Additionally, the proposed current-limit algorithm of the inverter can be implemented without additional hardware, and it increases the reliability of the UPS.

Journal ArticleDOI
TL;DR: Using a novel approach to model the rectifier current waveform, simple analytical equations are derived and the output DC voltage and the efficiency of the rectifiers are derived analytically.
Abstract: In this paper, a simple model for the UHF low power rectifier circuit is proposed. Using a novel approach to model the rectifier current waveform, simple analytical equations are derived. The output DC voltage and the efficiency of the rectifier are derived analytically. Simulation results of the rectifier using actual models are very close to those predicted by the proposed model. The derived formulas for the output DC voltage and the efficiency are simple and physically meaningful and can be used to optimize the performance of the rectifier.

Journal ArticleDOI
TL;DR: In this paper, a 12-pulse diode rectifier with a single-phase square wave auxiliary voltage supply is proposed to reduce the harmonics in the input currents of the rectifier.
Abstract: Diode rectifiers have been widely used for an ac-to-dc converter. A big problem is that they include large harmonic components in the input currents. A 12-pulse configuration is useful for reducing them, but it still includes the (12 mplusmnl)th (m: integer) harmonics in the input currents. In order to further reduce the input current harmonics a single-phase square wave auxiliary voltage supply is inserted in the middle dc bus. It reduces harmonics especially the 11th and 13th and the harmonic characteristic becomes almost equivalent to a 24-pulse rectifier. Theoretical analysis of the combined 12-pulse diode rectifier with the auxiliary supply is presented, and a control method of the auxiliary supply is proposed. The reduction in the input current harmonics is verified by simulation and experimental results. The auxiliary supply is also applied to a 12-pulse thyristor rectifier.

Journal ArticleDOI
TL;DR: In this article, an improved current-doubler rectifier with coupled inductors is proposed, which can extend duty ratio to reduce the peak current through the isolation transformer winding and lower output current ripple as well as voltage stress of the rectifier diodes.
Abstract: In this paper, an improved current-doubler rectifier with coupled inductors is proposed. The proposed rectifier can extend duty ratio to reduce the peak current through the isolation transformer winding and lower output current ripple as well as voltage stress of the rectifier diodes. In this study, a 500-W prototype with a full-bridge phase-shift converter, the proposed rectifier, with input voltage of 400 V and output voltage of 12 V was built. Theoretical analysis and experimental results have verified that the proposed rectifier is attractive for high step-down voltage and high-power applications.

Patent
06 Jun 2008
TL;DR: In this article, a proximity detector employs a first peak detector circuit and a second peak detector, both responsive to a magnetic field signal, each of which has a predetermined excursion limit in an outward direction away from a center voltage of the magnetic signal.
Abstract: A proximity detector employs a first peak detector circuit and a second peak detector circuit, both responsive to a magnetic field signal. The second peak detector circuit includes a positive peak detector circuit and a negative peak detector circuit, each of which have a predetermined excursion limit in an outward direction away from a center voltage of the magnetic field signal so as to be less affected by a large signature region in the magnetic field signal. The proximity detector also includes an output control circuit. The output control circuit is configured to provide an output signal, which, during a determined time period, changes state in response to the first peak detector circuit, and which, after the determined time period, changes state in response to the second peak detector circuit.

Journal ArticleDOI
TL;DR: Low input current distortion, fast voltage-loop response, and improved dynamic response against line and load disturbances are demonstrated experimentally on a 300-W digitally controlled boost rectifier operating at a switching frequency of 100 kHz.
Abstract: A single-phase boost rectifier system with conventional low-bandwidth voltage loop exhibits poor dynamic response. A simple method is presented to improve the dynamic response of the rectifier without affecting its steady-state performance. A fast voltage controller is used to improve the dynamic response of the rectifier. The increased low-frequency ripple at the output of the voltage controller is filtered out using a new filter. Design methodology for the voltage loop is presented. The filter is simple enough for analog and digital implementations. Low input current distortion, fast voltage-loop response, and improved dynamic response against line and load disturbances are demonstrated experimentally on a 300-W digitally controlled boost rectifier operating at a switching frequency of 100 kHz.

Patent
22 Apr 2008
TL;DR: In this article, the authors proposed a post regulation mechanism for synchronous rectifiers in DC-to-DC converters, where the rectifier may function as a modulator for post regulation over a limited range of output voltages suitable for load regulation.
Abstract: Methods and apparatus for regulating a synchronous rectifier DC-to-DC converter by adjusting one or more existing synchronous rectifiers in the converter are provided. By regulating an existing synchronous rectifier, the rectifier may function as a modulator for post regulation over a limited range of output voltages suitable for load regulation, without introducing an additional conversion stage for post regulation, which typically decreases efficiency and power density. Independent post regulation of an existing synchronous rectifier may improve the load regulation, reduce output voltage ripple, and improve the transient response of the converter. By operating independently from the main control loop, post regulation may most likely avoid the limitations of the main control loop, such as limited gain bandwidth and a relatively slow transient response. Such post regulation may be added to isolated or non-isolated switched-mode power supplies, such as forward or buck converters.

Journal ArticleDOI
TL;DR: In this paper, a novel high efficiency asymmetrical half-bridge converter using a self-driven synchronous rectifier is presented, which improves the system efficiency using the characteristics of the asymmetric half-branch converter and the self-drive rectifier.
Abstract: A novel high efficiency asymmetrical half-bridge converter using a self-driven synchronous rectifier is presented. The proposed converter improves the system efficiency using the characteristics of the asymmetrical half-bridge converter and the self-driven synchronous rectifier. The synchronous rectifier applied to the proposed converter is the new topological synchronous rectifier, which is a slightly modified type of the conventional synchronous rectifier used in the conventional asymmetrical half-bridge converter. The type of the new topological synchronous rectifier slightly changes the transformer structure and the synchronous switch connection in the asymmetrical half-bridge converter with a conventional self-driven synchronous rectifier. The operational principle of the proposed converter is explained in detail. Since the proposed converter utilises the transformer leakage inductor as its resonant inductor, its structure is simplified. A design example for a 90 W (12 V/7.5 A) prototype is discussed in detail. Experimental results are shown for the designed prototype converter under universal AC input voltage (180-265 V). It is shown that the efficiency of the proposed converter can be significantly improved.

Proceedings ArticleDOI
01 Feb 2008
TL;DR: An asynchronous full-wave rectifier for use with a multiple-electrode disk-shaped piezoelectric generator by using quarter-circle shaped electrodes, similar to an ultrasonic motor, to efficiently rectify the multiple output voltage phases generated from a disk- shaped transducer.
Abstract: This paper describes an asynchronous full-wave rectifier for use with a multiple-electrode disk-shaped piezoelectric generator. By using quarter-circle shaped electrodes, similar to an ultrasonic motor, multiple output voltage phases are obtained from a single resonating piezoelectric disk. Two-electrode transducer outputs are often rectified using a full-wave diode bridge rectifier, which requires a significant voltage drop between input and output, decreasing the rectifier's voltage efficiency. Previous asynchronous rectifiers use MOS switches to avoid the diode drop, however they lack the ability to efficiently rectify the multiple output phases generated from a disk-shaped transducer. Other CMOS rectifiers need two input waveforms that are equal and opposite, which a piezoelectric transducer may not generate for many input vibrations.

Patent
Shoji Ootaka1, Toshiyuki Umeda1
05 Aug 2008
TL;DR: In this paper, a rectifier circuit with a first MOS transistor, a second MOS transistors, and a second switching circuit for supplying a bias voltage to the first transistor in response to a control signal is described.
Abstract: A rectifier circuit includes a first MOS transistor; a first capacitor connected between a gate and a source of the first MOS transistor; a first switching circuit for supplying a bias voltage to the first capacitor in response to a control signal; a second MOS transistor whose drain is connected to the source of the first MOS transistor; a second capacitor connected between a gate and a source of the second MOS transistor; and a second switching circuit for supplying the bias voltage to the second capacitor in response to the control signal. The rectifier circuit also includes a third MOS transistor for imitating the first MOS transistor; a third capacitor for imitating the first capacitor; a dummy switching circuit for supplying the bias voltage to the third capacitor in response to the control signal; and a generating circuit for generating the control signal based on a potential of the third capacitor.

Journal ArticleDOI
TL;DR: In this paper, an IGBT-based auxiliary converter (AXC) system is proposed to compensate the harmonic current of the rectifier when the load consumes power, which can achieve unity power factor operation and regeneration.
Abstract: In variable-speed drives systems, diode rectifiers and thyristor rectifiers are often used as the front-end circuit for AC-DC conversion. The advantages of the conventional rectifier are its simplicity and high reliability. The drawbacks include the harmonic current distortion and the lack of regeneration capability. In recent years, industries adopt the transistor-based active front-end (AFE) technologies to accomplish high power factor operation and re-generation capability. However, the cost of AFE is much higher than the conventional diode/thyristor front-end. Besides, the AFE is often less reliable than the diode/thyristor front-end under utility transients. In this paper, an IGBT-based auxiliary converter (AXC) system is proposed. The AXC operates as a shunt active filter to compensate the harmonic current of the rectifier when the load consumes power. When the dc load re-generates, the AXC system can channel the re-generation energy back into the utility system. The combination of the diode rectifier and the AXC can accomplish unity power factor operation and regeneration, but it also causes circulating current between the AXC and the rectifier, which leads to higher operational losses and higher noise level. The mechanism of the circulating current is analyzed in this paper, and solutions are also presented. Computer simulation and field test results are presented to validate the performance of the proposed AXC system.

Patent
01 Aug 2008
TL;DR: In this article, a rectifier connected with an AC source through a reactor, a plurality of capacitors connected in series between output terminals of the rectifier, first switching means connected between one input terminal of the Rectifier and a connection point of the plurality of the capacitors in inverse-parallel, and a plurality diodes connected with the plurality in inverse parallel are provided.
Abstract: A rectifier connected with an AC source through a reactor, a plurality of capacitors connected in series between output terminals of the rectifier, first switching means connected between one input terminal of the rectifier and a connection point of a plurality of capacitors, second switching means connected between the other input terminal of the rectifier and the connection point of a plurality of capacitors, and a plurality of diodes connected with the plurality of capacitors in inverse-parallel are provided.

Proceedings ArticleDOI
15 Jun 2008
TL;DR: In this paper, the authors proposed a DC-link AC-drive for HVAC applications, where all traditional passive rectifier components are replaced with a "small" DClink film capacitor.
Abstract: 3-phase AC-drives for HVAC applications (heating, ventilation & air-conditioning) typically employ a passive diode rectifier and an electrolytic DC-link capacitor to filter the rectified line voltage. The DC capacitor may be accompanied by AC or DC-chokes for harmonic line- current reduction. Recently, commercial HVAC drives, where all traditional passive rectifier components are replaced with a "small" DC-link film capacitor, have emerged. These are referred to as slim DC-link AC-drives. This AC-drive is compared to traditional types below.

Journal ArticleDOI
TL;DR: In this paper, a three-phase, multilevel rectifier using active voltage injection with one MOSFET device is presented, where the injector consists of a bidirectional switch that modifies the behavior of a 12-pulse rectifier resulting in either 24pulse or multi-level pulsewidth modulated (PWM) operation.
Abstract: A three-phase, multilevel rectifier using active voltage injection with one MOSFET device is presented. The injector consists of a bidirectional switch that modifies the behavior of a 12-pulse rectifier resulting in either 24-pulse or multilevel pulsewidth-modulated (PWM) operation. The resultant input currents are almost sinusoidal, the line current THD being 2.36% for 24-pulse operation and 1.06% for PWM operation. The MOSFET current is 2.9% of the load current. The circuit operation, idealized waveforms and modulation strategy are explained and experimental results are presented.