A Novel Power Factor Correction Rectifier for Enhancing Power Quality

Author(s):  
Bindu K V ◽  
B Justus Rabi

In this paper, the disturbances in power system due to low quality of power are discussed and a current injection method to maintain the sinusoidal input current which will reduce the total current harmonic distortion (THD) as well as improve the power factor nearer to unity is proposed. The proposed method makes use of a novel controlled diode rectifier which involves the use of bidirectional switches across the front-end rectifier and the operation of the converter is fully analyzed. The main feature of the topology is low cost, small size, high efficiency and simplicity, and is excellent for retrofitting front-end rectifier of existing ac drives, UPS etc. A novel strategy implementing reference compensation current depending on the load harmonics and a control algorithm for three-phase three-level unity PF rectifier which draws high quality sinusoidal supply currents and maintains good dc link- voltage regulation under wide load variation. The proposed technique can be applied as a retrofit to a variety of existing thyristor converters which uses three bidirectional switches operating at low frequency and a half-bridge inverter operating at high frequency .The total power delivered to the load is processed by the injection network, the proposed converter offers high efficiency and not only high power factor but also the Total Harmonic Distortion is reduced. Theoretical analysis is verified by digital simulation and a hardware proto type module is implemented in order to confirm the feasibility of the proposed system. This scheme in general is suitable for the common variable medium-to high-power level DC load applications.

2004 ◽  
Vol 13 (03) ◽  
pp. 557-576
Author(s):  
CHUNG-WOOK ROH ◽  
GUN-WOO MOON ◽  
MYUNG-JOONG YOUN

This paper presents a new single-stage single-switched forward converter with magnetic coupled nondissipative snubber, which gives good power factor correction (PFC), low current harmonic distortion, and tight output voltage regulation. The proposed converter features low switch current and voltage stresses, essential for the design of a single-stage power factor correction converter. The prototype shows that the IEC1000-3-2 requirements are met satisfactorily with nearly unity power factor. This proposed converter with magnetic coupled nondissipative snubber is particularly suited for power supply applications with low power level.


Energies ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 4949
Author(s):  
Mena ElMenshawy ◽  
Ahmed Massoud

To increase the adoption of electric vehicles (EVs), significant efforts in terms of reducing the charging time are required. Consequently, ultrafast charging (UFC) stations require extensive investigation, particularly considering their higher power level requirements. Accordingly, this paper introduces a hybrid multimodule DC-DC converter-based dual-active bridge (DAB) topology for EV-UFC to achieve high-efficiency and high-power density. The hybrid concept is achieved through employing two different groups of multimodule converters. The first is designed to be in charge of a high fraction of the total required power, operating at a relatively low switching frequency, while the second is designed for a small fraction of the total power, operating at a relatively high switching frequency. To support the power converter controller design, a generalized small-signal model for the hybrid converter is studied. Also, cross feedback output current sharing (CFOCS) control for the hybrid input-series output-parallel (ISOP) converters is examined to ensure uniform power-sharing and ensure the desired fraction of power handled by each multimodule group. The control scheme for a hybrid eight-module ISOP converter of 200 kW is investigated using a reflex charging scheme. The power loss analysis of the hybrid converter is provided and compared to conventional multimodule DC-DC converters. It has been shown that the presented converter can achieve both high efficiency (99.6%) and high power density (10.3 kW/L), compromising between the two other conventional converters. Simulation results are provided using the MatLab/Simulink software to elucidate the presented concept considering parameter mismatches.


Electronics ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1340
Author(s):  
Yih-Her Yan ◽  
Hung-Liang Cheng ◽  
Chun-An Cheng ◽  
Yong-Nong Chang ◽  
Zong-Xun Wu

A novel single-switch single-stage high power factor LED driver is proposed by integrating a flyback converter, a buck–boost converter and a current balance circuit. Only an active switch and a corresponding control circuit are used. The LED power can be adjusted by the control scheme of pulse–width modulation (PWM). The flyback converter performs the function of power factor correction (PFC), which is operated at discontinuous-current mode (DCM) to achieve unity power factor and low total current harmonic distortion (THDi). The buck–boost converter regulates the dc-link voltage to obtain smooth dc voltage for the LED. The current–balance circuit applies the principle of ampere-second balance of capacitors to obtain equal current in each LED string. The steady-state analyses for different operation modes is provided, and the mathematical equations for designing component parameters are conducted. Finally, a 90-W prototype circuit with three LED strings was built and tested. Experimental results show that the current in each LED string is indeed consistent. High power factor and low THDi can be achieved. LED power is regulated from 100% to 25% rated power. Satisfactory performance has proved the feasibility of this circuit.


Electronics ◽  
2021 ◽  
Vol 10 (13) ◽  
pp. 1520
Author(s):  
José Teixeira Gonçalves ◽  
Stanimir Valtchev ◽  
Rui Melicio ◽  
Alcides Gonçalves ◽  
Frede Blaabjerg

The hybrid three-phase rectifiers (HTR) consist of parallel associations of two rectifiers (rectifier 1 and rectifier 2), each one of them with a distinct operation, while the sum of their input currents forms a sinusoidal or multilevel waveform. In general, rectifier 1 is a GRAETZ (full bridge) (can be combined with a BOOST converter) and rectifier 2 is combined with a DC-DC converter. In this HTR contest, this paper is intended to answer some important questions about those hybrid rectifiers. To obtain the correct answers, the study is conducted as an analysis of a systematic literature review. Thus, a search was carried out in the databases, mostly IEEE and IET, and 34 papers were selected as the best corresponding to the HTR theme. It is observed that the preferred form of power distribution in unidirectional hybrid three-phase rectifiers (UHTR) is 55%Po (rectifier 1) and 45%Po (rectifier 2). For the bidirectional hybrid three-phase rectifiers (BHTR), rectifier 1 preferably takes 90% of Po and 10% of Po is processed by rectifier 2. It is also observed that the UHTR that employ the single-ended primary-inductor converter (SEPIC) or VIENNA converter topologies in rectifier 2 can present sinusoidal input currents with low total harmonic distortion (THD) and high Power Factor (PF), even successfully complying with the international standards. The same can be said about the rectifier that employs a pulse-width (PWM) converter of BOOST topology in rectifier 2. In short, the HTR are interesting because they allow using the GRAETZ full bridge topology in rectifier 1, thus taking advantage of its characteristics, being simple, robust, and reliable. At the same time, the advantages of rectifier 2, i.e., high PF and low THD, are well used. In addition, this article also points out the future direction of research that is still unexplored in the literature, thus giving opportunities for future innovation.


2012 ◽  
Vol 433-440 ◽  
pp. 5549-5555
Author(s):  
Yun Tao Yue ◽  
Yan Lin

A novel scheme of low power communication power supply with high power factor and soft-switching is presented, a power factor corrector and dc/dc converter of passive lossless soft-switching is based on a ML4803 IC control. DC/DC converter introduces a novel two-transistor forward soft-switching technique, which realizes zero-voltage turn-on and turn-off, with no additional switches. a communication power supply module is developed in this paper. It has the characteristics of rapid dynamic response, high power factor, high efficiency and small bulk ect.


2006 ◽  
Vol 911 ◽  
Author(s):  
Christopher Harris ◽  
Andrei O Konstantinov ◽  
Jan-Olov Svedberg ◽  
Ian Ray ◽  
Christer Hallin

AbstractThe development of high power, high efficiency silicon carbide RF MESFETs is reported. High power densities of over 3W/mm have been measured for devices with total power output in excess of 25W. The devices have been fabricated using a novel lateral epitaxy technique. The MESFET employs a buried p-type depletion stopper in order to suppress short channel effects and increase the operation voltage. The use of the depletion stopper also allows high RF signal gain, while maintaining high voltage operation capability. Single-cell components measured on-wafer demonstrate an Ft of 10 GHz and a high unilateral gain.Packaged 6-mm RF transistors have been evaluated using amplifier circuits designed for operation in classes A, AB or C. Operation in class AB demonstrated a saturated power of 20 W and a P1dB of 15W with a linear gain of over 16 dB at Vdd of 60 V for 2.25 GHz operation. Maximum drain efficiency is 56% for class AB operation, 48% at 1 dB compression point and 72% for class C at 2.25 GHz.


2013 ◽  
Vol 3 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Yuriy Denisov ◽  
Serhii Stepenko

Abstract The problems, devoted to power quality and particularly power factor correction, are of great importance nowadays. The key requirements, which should be satisfied according to the energy efficiency paradigm, are not limited only by high quality of the output voltage (low total harmonic distortion), but also assume minimal power losses (high efficiency) in the power factor corrector (PFC). It could be satisfied by the use of quasi-resonant pulse converter (QRPC) due to its high efficiency at high switching frequency instead of the classical pulse-width modulated (PWM) boost converter. A dynamic model of QRPC with zero current switching (ZCS) is proposed. This model takes into account the main features of QRPC-ZCS as a link of a PFC closed-loop system (discreteness, sharp changes of parameters over switching period, input voltage impact on the gain). The synthesized model is also valid for conventional parallel pulse converter over an active interval of commutation. The regulator for current loop of PFC was synthesized based on digital filter using proposed model by the criterion of fast acting.


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