Showing papers on "PWM rectifier published in 1993"
TL;DR: A fully-software-controlled pulse-width-modulated (PWM) rectifier with a current link is presented, showing that unity power factor is achieved by the lagging of the input current of the rectifiers with respect to the source voltage.
Abstract: A fully-software-controlled pulse-width-modulated (PWM) rectifier with a current link is presented. The rectifier uses six switches to connect the three-phase source of the load directly. Line power factor is controlled while maintaining DC current. The input filter of the rectifier is analyzed, showing that unity power factor is achieved by the lagging of the input current of the rectifier with respect to the source voltage. The PWM technique is developed using a space vector modulation, and its implementation is carried out with a minimal control hardware structure based on a 16 b single-chip microcomputer. It is shown experimentally that the scheme gives good performance. >
76 citations
01 Nov 1993
TL;DR: In this article, a voltage-source inverter without DC link components is proposed to eliminate the electrolytic capacitor which has a short life compared with an AC capacitor (metalised polyester film, etc.).
Abstract: Voltage-source inverters are normally equipped with an electrolyte capacitor in their DC link. A voltage-source inverter without DC link components is proposed to eliminate the electrolytic capacitor which has a short life compared with an AC capacitor (metalised polyester film, etc.). This inverter system requires an AC filter composed of L and C in the AC source side. In this case, the most important problem is the reduction of AC filter capacity. To achieve this reduction, the rectifier section is operated by PWM control. The waveform of the AC source current is also improved. Steady-state analysis, the calculated characteristics of the AC filter capacity and the waveforms of voltage and current are described for a 0.75 kW induction motor driven by the system. The AC filter capacity is reduced to about 38% of the rectifier without PWM. Measured waveforms are presented for a motor slip of 4%. The stability with, and without, DC link components, is also discussed.
75 citations
Patent•
17 Sep 1993TL;DR: In this article, a switching rectifier circuit that combines the conventional three-phase, 6-stepped PWM rectifier/inverter circuit with a simple, low-power switch commutation circuit to provide zero-voltage turn-on for the switches, and soft turn-off for the diodes.
Abstract: A novel switching rectifier circuit that combines the conventional three-phase, 6-stepped PWM rectifier/inverter circuit with a simple, low-power switch commutation circuit to provide zero-voltage turn-on for the switches, and soft turn-off for the diodes. The main features of the new circuit include elimination of switching losses on the power switches and reverse recovery problems on the diodes, elimination of the need for any snubbers in the three-phase bridge, possibility of use of slower diodes in the power bridge, constant frequency operation, and no increase in component current and voltage stresses over the conventional PWM rectifier.
34 citations
20 Jun 1993
TL;DR: In this article, the modeling and control of a PWM rectifier in the case of network variations is studied, where the aim is to limit and stabilize stable variation of DC output voltage and line currents in such circumstances.
Abstract: The modeling and control of a PWM rectifier in the case of network variations are studied. The aim is to limit and stabilize stable variation of DC output voltage and line currents in such circumstances. A line current compensation loop method coupled with identification of network parameters is compared to another approach using a robust DC voltage regulator. >
34 citations
02 Oct 1993
TL;DR: In this paper, a current-controlled current-source-type unity power factor PWM rectifier is proposed, where three input line currents are controlled independently to obtain sinusoidal currents with low oscillations during transients.
Abstract: A current-controlled current-source-type unity power factor PWM (pulse-width-modulated) rectifier is proposed. The three input line currents are controlled independently to obtain sinusoidal currents with low oscillations during transients. Power factor is controlled directly, and unity power factor operation can readily be achieved. Output DC voltage is regulated by varying the amplitude of the AC input current references. The proposed rectifier exhibits excellent steady-state operation and good transient dynamics, a result of the current control method used. A complete analysis of the PWM rectifier and control circuitry is given, and design guidelines are discussed. The theoretical results and design equations are verified by simulation and experiments on a 1.5 kVA prototype unit. >
30 citations
15 Nov 1993
TL;DR: In this paper, a new rectifier controlled by predictive instantaneous-current PWM control schemes for reducing AC-side harmonic currents in consideration of the DC-side voltage ripple is proposed.
Abstract: A new rectifier controlled by predictive instantaneous-current PWM control schemes for reducing AC-side harmonic currents in consideration of the DC-side voltage ripple is proposed. Unity power factor is also obtained. The paper describes three control schemes for a single-phase rectifier, and experimental and simulation studies of rectifier performance. The effectiveness of the control schemes is confirmed by experiments and simulations. The rectifier can be used in applications such as UPS systems and static VAr compensators. >
30 citations
15 Nov 1993
TL;DR: In this paper, a current-controlled PWM rectifier is proposed to provide near sinusoidal input currents with unity power factor and a low output voltage ripple, which produces a well-defined input current harmonic spectrum, exhibits fast transient response to load voltage variations and is capable of regenerative operation.
Abstract: Active front-end rectifiers with reduced input current harmonics and high input power factor are becoming a must in utility interfaced applications. With forced-commutated switches, the voltage source inverter approach is superior to the conventional current source approach, in terms of number of components and control options. However, the straight-forward delta control of the rectifier is characterized by a slow response and potential stability problems. This paper proposes a current-controlled PWM rectifier as an alternative. It provides near sinusoidal input currents with unity power factor and a low output voltage ripple. Moreover, it produces a well-defined input current harmonic spectrum, exhibits fast transient response to load voltage variations and is capable of regenerative operation. PWM pattern generation is based on a carrier technique and the current controller is implemented in the: (a) stationary (abc) frame; and (b) rotating (dqo) frame. The design and the performance of the two controller options are investigated and compared. >
22 citations
07 Mar 1993
TL;DR: A PWM rectifier, including an uncontrolled rectifier and a Cuk power converter stage driven by a sliding-mode controller, is described, and a fast and stable response is achieved, in spite of the large output filter.
Abstract: A PWM rectifier, including an uncontrolled rectifier and a Cuk power converter stage driven by a sliding-mode controller, is described. Similar to other high-quality rectifiers, this solution allows low distortion and in-phase line current. Due to the sliding-mode control, a fast and stable response is achieved, in spite of the large output filter. Control complexity is the same as standard current-mode controls, Converter analysis, design criteria, and experimental results are presented. >
17 citations
07 Mar 1993
TL;DR: In this article, a digital-signal-processor-based controller for three-phase, space-vector modulated converters is presented for the control of a 2 kW, zero-voltage-switched matrix-converter-based threephase PWM rectifier.
Abstract: The implementation of a digital-signal-processor-based controller for three-phase, space-vector modulated converters is presented. The implementation is illustrated for the control of a 2 kW, zero-voltage-switched matrix-converter-based three-phase PWM rectifier. The controller feature very high data processing speed (converter switching frequency of 100 kHz), and provides high-quality, low-distortion converter input currents and output voltages. The controller can be implemented using only a few standard integrated circuits. >
12 citations
01 Jun 1993
TL;DR: A symmetrical PWM CSI topology with a two loop control structure that has regenerative capabilities, inherent short circuit protection and increased reliability, and is particularly well suited for fast fluctuating loads is proposed.
Abstract: PWM current source inverters (CSI's) are usually operated with a fixed pattern and fed from a thyristor rectifier controlled current source Transient response of the output current is slow and input power factor is low This paper proposes a symmetrical PWM CSI topology with a two loop control structure A voltage regulated current source inverter ensures instantaneous output voltage control through on-line PWM current generation The PWM rectifier maintains unity displacement power factor, thus improving the power factor Furthermore, it maintains the DC link current to a value such that the inverter modulation index remains high at all times; this results in reduced voltage harmonic distortion at the output The topology is particularly well suited for fast fluctuating loads It also has regenerative capabilities, inherent short circuit protection and increased reliability The paper describes the power circuit topology and the two control loop structure and presents controller design considerations and procedures The complete topology is implemented on a 2 kVA unit and experimental results confirm theoretical and simulation results >
6 citations
19 Apr 1993
TL;DR: In this article, a soft-switched AC/DC power converter structure was proposed for current-fed inverters and forced-commutated PWM rectifiers with inductive loads.
Abstract: This paper presents a soft-switched AC/DC power converter structure, useful for current-fed inverters and forced-commutated PWM rectifiers with inductive loads. Typical applications are high-power AC motor drives, magnet power supplies and active power filters with inductive energy storage. As compared to hard-switched power converters, the proposed solution calls for some increase of the circuit complexity, but provides improved input and output performances due to the higher switching frequency. Further improvements are ensured by proper control of the commutation process. Actual power converter capabilities are demonstrated by experimental results. >
14 Sep 1993
TL;DR: In this paper, the analysis and design of a direct six-switch three-phase PWM rectifier, capable of correcting input unbalance, is presented, based on the input source positive and negative sequence components, an unbalanced transfer matrix in terms of input phase voltages is derived.
Abstract: The analysis and design of a direct six-switch three-phase PWM rectifier, capable of correcting input unbalance, is presented. Based on the input source positive and negative sequence components, an unbalanced transfer matrix in-terms of input phase voltages is derived. An online method is used to implement the transfer matrix function and generate the switch gating signals. As compared to other unbalance correction methods the proposed approach is very simple to implement. It uses a minimum of discrete analog and digital components. The algorithm of the proposed approach is described, and experimental results from a 1 kVA breadboard are provided for verification. >
27 Sep 1993
TL;DR: Simulation results from a study of the PWM rectifier with the proposed control strategy show that the transient performance is improved and the supply current follows closely the reference current even for very low resistance of AC side inductors.
Abstract: A new control strategy for a three phase voltage type PWM rectifier is described. This control strategy introduces state feedback control of an LC filter inserted on the AC side of the power converter and has the advantage of fast response to changes in the input current and in the load while operating with unity power factor and sinusoidal AC supply currents to produce a regulated DC voltage. Simulation results from a study of the PWM rectifier with the proposed control strategy show that the transient performance is improved and the supply current follows closely the reference current even for very low resistance of AC side inductors. Experimental results are also included to confirm the effectiveness of the proposed control strategy. >
TL;DR: In this article, the authors describe circuit configurations of current output type rectifer with full-bridge or half-bridge, and new type rectifiers with auxiliary devices, and the best one among the presented circuits is discussed on the switching frequency, the voltage stress of the devices and the circuit reliability.
Abstract: This paper describes circuit configurations of current output type rectifer. The rectifiers with full-bridge or half-bridge, and new type rectifiers with auxiliary devices are presented. A pulsewidth modulation (PWM) strategy is employed to obtain sinusoidal input current with unity power factor. The PWM methods for each circuits are described and the circuit operations are explained. The voltage and the current waveforms in the experiments for static RL loads are shown, and the steady state characteristics are given. The circuits are compared, and the best one among the presented circuits is discussed on the switching frequency, the voltage stress of the devices, and the circuit reliability, etc.. The experiments show that the use of a double PWM method for the circuit with auxiliary devices contributes to decreasing the ripple in the sinusoidal input current wave.