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Hussain S. Athab - One of the best experts on this subject based on the ideXlab platform.

  • An Efficient Single-Switch Quasi-Active PFC Converter With Continuous Input Current and Low DC-Bus Voltage Stress
    IEEE Transactions on Industrial Electronics, 2014
    Co-Authors: Hussain S. Athab, Dylan Dah-chuan Lu, Amirnaser Yazdani, Bin Wu
    Abstract:

    This paper proposes a novel single-switch quasi-active power factor correction (PFC) converter based on two flyback dc/dc modules. To achieve a high efficiency, part of the Input power is directly transferred to the load by the first dc/dc module. The rest of the Input power is stored in the dc-bus capacitor and reprocessed by the second dc/dc module. Together, the dc-bus capacitor and the second dc/dc module also serve as a regenerative snubber. Furthermore, a quasi-active PFC circuit is provided to improve the power factor and to ensure the continuous current mode (CCM) operation of the Input Inductor without the need for sophisticated feedforward sensing and control mechanism. The quasi-active PFC circuit is driven by a magnetic switch, through the tertiary winding of the transformer of the first flyback module. The Input current harmonics of the proposed converter meet the IEC 61000-3-2 (Classes A, C, and D) requirements. The dc-bus capacitor voltage is always less than the Input voltage regardless of the load condition and is fairly invariant to large variations of the Input voltages. High power factor with CCM operation and fast output voltage regulation have been achieved through a single-loop controller. Operating principles, analysis, and experimental results are presented to verify the effectiveness of the proposed converter.

  • a single switch ac dc flyback converter using a ccm dcm quasi active power factor correction front end
    IEEE Transactions on Industrial Electronics, 2012
    Co-Authors: Hussain S. Athab, Dylan Dah-chuan Lu, K. Ramar
    Abstract:

    This paper discusses the major issues that exist in the single-stage ac/dc converters with power factor correction (PFC) and presents a novel converter based on a quasi-active PFC scheme. Two additional windings wound in the transformer of a conventional dc/dc flyback converter are used to drive and achieve continuous current mode operation of an Input Inductor. In addition, direct energy transfer paths are provided through the additional windings to improve the conversion efficiency and to reduce the dc bus capacitor voltage below 450 V for universal line applications. The proposed converter can be easily designed to comply with IEC 61000-3-2 Class D requirement and to achieve fast output voltage regulation. By properly tuning the converter parameters, a good tradeoff between efficiency, dc bus capacitor voltage stress, and harmonic content can be achieved. Operating principles, analysis, and experimental results of the proposed method are presented.

  • Electronics; Studies from Multimedia University describe new findings in electronics
    2010
    Co-Authors: Hussain S. Athab
    Abstract:

    The auxiliary winding is placed between the Input rectifier and the low-frequency filter capacitor to serve as a magnetic switch to drive an Input Inductor. Since the dc/dc converter is operated at high-switching frequency, the auxiliary windings produce a high frequency pulsating source such that the Input current conduction angle is significantly lengthened and the Input current harmonics is reduced.

  • A High-Efficiency AC/DC Converter With Quasi-Active Power Factor Correction
    IEEE Transactions on Power Electronics, 2010
    Co-Authors: Hussain S. Athab, Dylan Dah-chuan Lu
    Abstract:

    This letter presents a novel ac/dc converter based on a quasi-active power factor correction (PFC) scheme. In the proposed circuit, the power factor is improved by using an auxiliary winding coupled to the transformer of a cascade dc/dc flyback converter. The auxiliary winding is placed between the Input rectifier and the low-frequency filter capacitor to serve as a magnetic switch to drive an Input Inductor. Since the dc/dc converter is operated at high-switching frequency, the auxiliary windings produce a high frequency pulsating source such that the Input current conduction angle is significantly lengthened and the Input current harmonics is reduced. It eliminates the use of active switch and control circuit for PFC, which results in lower cost and higher efficiency. In order to achieve low harmonic content, the Input Inductor is designed to operate in discontinuous current mode. Operating principles, analysis, and experimental results of the proposed method are presented.

  • An efficient quasi-active power factor correction scheme
    2009 IEEE Symposium on Industrial Electronics & Applications, 2009
    Co-Authors: Hussain S. Athab, K. Ramar, Dylan Dah-chuan Lu
    Abstract:

    This paper presents a novel Input current shaper based on a quasi-active power factor correction (PFC) scheme. The power factor is improved by adding two auxiliary windings coupled to the transformer of a cascade dc/dc flyback converter. The auxiliary windings are placed between the Input rectifier and the low-frequency filter capacitor to serve as a magnetic switch to drive an Input Inductor. Since the dc/dc converter is operated at high switching frequency, the auxiliary windings produce a high frequency pulsating source such that the Input current conduction angle is significantly lengthened and the Input current harmonics is reduced. It eliminates the use of active switch and control circuit for PFC. The Input Inductor can be designed to operate in discontinuous current mode (DCM) with lower harmonic content or continuous conduction mode (CCM) with higher efficiency. However, a trade-off between efficiency and harmonic content must be made. Operating principles, analysis, simulation and practical results of the proposed method are presented.

Dylan Dah-chuan Lu - One of the best experts on this subject based on the ideXlab platform.

  • An Efficient Single-Switch Quasi-Active PFC Converter With Continuous Input Current and Low DC-Bus Voltage Stress
    IEEE Transactions on Industrial Electronics, 2014
    Co-Authors: Hussain S. Athab, Dylan Dah-chuan Lu, Amirnaser Yazdani, Bin Wu
    Abstract:

    This paper proposes a novel single-switch quasi-active power factor correction (PFC) converter based on two flyback dc/dc modules. To achieve a high efficiency, part of the Input power is directly transferred to the load by the first dc/dc module. The rest of the Input power is stored in the dc-bus capacitor and reprocessed by the second dc/dc module. Together, the dc-bus capacitor and the second dc/dc module also serve as a regenerative snubber. Furthermore, a quasi-active PFC circuit is provided to improve the power factor and to ensure the continuous current mode (CCM) operation of the Input Inductor without the need for sophisticated feedforward sensing and control mechanism. The quasi-active PFC circuit is driven by a magnetic switch, through the tertiary winding of the transformer of the first flyback module. The Input current harmonics of the proposed converter meet the IEC 61000-3-2 (Classes A, C, and D) requirements. The dc-bus capacitor voltage is always less than the Input voltage regardless of the load condition and is fairly invariant to large variations of the Input voltages. High power factor with CCM operation and fast output voltage regulation have been achieved through a single-loop controller. Operating principles, analysis, and experimental results are presented to verify the effectiveness of the proposed converter.

  • a single switch ac dc flyback converter using a ccm dcm quasi active power factor correction front end
    IEEE Transactions on Industrial Electronics, 2012
    Co-Authors: Hussain S. Athab, Dylan Dah-chuan Lu, K. Ramar
    Abstract:

    This paper discusses the major issues that exist in the single-stage ac/dc converters with power factor correction (PFC) and presents a novel converter based on a quasi-active PFC scheme. Two additional windings wound in the transformer of a conventional dc/dc flyback converter are used to drive and achieve continuous current mode operation of an Input Inductor. In addition, direct energy transfer paths are provided through the additional windings to improve the conversion efficiency and to reduce the dc bus capacitor voltage below 450 V for universal line applications. The proposed converter can be easily designed to comply with IEC 61000-3-2 Class D requirement and to achieve fast output voltage regulation. By properly tuning the converter parameters, a good tradeoff between efficiency, dc bus capacitor voltage stress, and harmonic content can be achieved. Operating principles, analysis, and experimental results of the proposed method are presented.

  • A High-Efficiency AC/DC Converter With Quasi-Active Power Factor Correction
    IEEE Transactions on Power Electronics, 2010
    Co-Authors: Hussain S. Athab, Dylan Dah-chuan Lu
    Abstract:

    This letter presents a novel ac/dc converter based on a quasi-active power factor correction (PFC) scheme. In the proposed circuit, the power factor is improved by using an auxiliary winding coupled to the transformer of a cascade dc/dc flyback converter. The auxiliary winding is placed between the Input rectifier and the low-frequency filter capacitor to serve as a magnetic switch to drive an Input Inductor. Since the dc/dc converter is operated at high-switching frequency, the auxiliary windings produce a high frequency pulsating source such that the Input current conduction angle is significantly lengthened and the Input current harmonics is reduced. It eliminates the use of active switch and control circuit for PFC, which results in lower cost and higher efficiency. In order to achieve low harmonic content, the Input Inductor is designed to operate in discontinuous current mode. Operating principles, analysis, and experimental results of the proposed method are presented.

  • An efficient quasi-active power factor correction scheme
    2009 IEEE Symposium on Industrial Electronics & Applications, 2009
    Co-Authors: Hussain S. Athab, K. Ramar, Dylan Dah-chuan Lu
    Abstract:

    This paper presents a novel Input current shaper based on a quasi-active power factor correction (PFC) scheme. The power factor is improved by adding two auxiliary windings coupled to the transformer of a cascade dc/dc flyback converter. The auxiliary windings are placed between the Input rectifier and the low-frequency filter capacitor to serve as a magnetic switch to drive an Input Inductor. Since the dc/dc converter is operated at high switching frequency, the auxiliary windings produce a high frequency pulsating source such that the Input current conduction angle is significantly lengthened and the Input current harmonics is reduced. It eliminates the use of active switch and control circuit for PFC. The Input Inductor can be designed to operate in discontinuous current mode (DCM) with lower harmonic content or continuous conduction mode (CCM) with higher efficiency. However, a trade-off between efficiency and harmonic content must be made. Operating principles, analysis, simulation and practical results of the proposed method are presented.

Heung-geun Kim - One of the best experts on this subject based on the ideXlab platform.

  • switched coupled Inductor quasi z source inverter
    IEEE Transactions on Power Electronics, 2016
    Co-Authors: Hafiz Furqan Ahmed, Honnyong Cha, Suhan Kim, Heung-geun Kim
    Abstract:

    Z-source inverters have become a research hotspot because of their single-stage buck–boost inversion ability, and better immunity to EMI noises. However, their boost gains are limited, because of higher component-voltage stresses and poor output power quality, which results from the tradeoff between the shoot-through interval and the modulation index. To overcome these drawbacks, a new high-voltage boost impedance-source inverter called a switched-coupled-Inductor quasi-Z-source inverter (SCL-qZSI) is proposed, which integrates a switched-capacitor and a three-winding switched-coupled Inductor (SCL) into a conventional qZSI. The proposed SCL-qZSI adds only one capacitor and two diodes to a classical qZSI, and even with a turns ratio of 1, it has a stronger voltage boost-inversion ability than existing high-voltage boost (q)ZSI topologies. Therefore, compared with other (q)ZSIs for the same Input and output voltages, the proposed SCL-qZSI utilizes higher modulation index with lower component-voltage stresses, has better spectral performance, and has a lower Input Inductor current ripple and flux density swing or, alternately, it can reduce the number of turns or size of the Input Inductor. The size of the coupled Inductor and the total number of turns required for three windings are comparable to those of a single Inductor in (q)ZSIs. To validate its advantages, analytical, simulation, and experimental results are also presented.

  • novel single phase pwm ac ac converters solving commutation problem using switching cell structure and coupled Inductor
    IEEE Transactions on Power Electronics, 2015
    Co-Authors: Hyunhak Shin, Honnyong Cha, Heung-geun Kim, Dongwook Yoo
    Abstract:

    This paper presents novel single-phase pulse width modulation (PWM) ac-ac converters that can solve the commutation problem in single-phase direct PWM ac-ac converters without sensing the Input voltage polarity. By using a basic switching cell structure and coupled Inductors, the proposed ac-ac converters can be short- and open-circuited without damaging the switching devices. Neither lossy RC snubber nor dedicated soft commutation strategy is required in the proposed converter. By replacing the conventional phase-leg of the PWM ac-ac converters with the switching cell structure and the coupled Inductor, three novel buck, boost, and buck-boost type PWM ac-ac converters are developed. Although two coupled Inductors are required for the proposed converter, the Input Inductor of the proposed converter can be much smaller than that of the conventional PWM ac-ac converters. The volume of the magnetic components can be further reduced by increasing switching frequency of the converter because very fast recovery diodes can be selected externally. In order to verify performance and robustness of the proposed converter, a 200-W boost type prototype converter was built and tested with both mismatched gate signals and highly distorted Input voltage.

K. Mauch - One of the best experts on this subject based on the ideXlab platform.

  • Modified boost converter with continuous Inductor current mode and ripple free Input current
    PESC Record. 27th Annual IEEE Power Electronics Specialists Conference, 1996
    Co-Authors: Jing Wang, William G. Dunford, K. Mauch
    Abstract:

    The boost topology is very popular in industry. However, the Input Inductor current ripple affects its ability to meet EMI requirements. A ripple-free Input Inductor current boost topology operating in continuous Inductor current mode is introduced in this paper. It is of simple topology and simple control strategy (the same as PWM). The proposed boost topology retains the advantages of the conventional boost topology, but with ripple-free Input current. Simulation and experimental results are presented to verify the predicted theory.

  • A Fixed Frequency, Fixed Duty Cycle Boost Converter with Ripple Free Input Inductor Current for Unity Power Factor Operation
    1996
    Co-Authors: Jing Wang, William G. Dunford, K. Mauch
    Abstract:

    A fixed frequency, fixed duty cycle Boost con- lar pulsating current, the Input current harmonics are very verter with continuous Input Inductor current for unity severe. power factor operation is introduced in this paper. The pro- When the conventional Boost converter operates with posed Boost convert has the same "voltage follower" (unity DICM, a high switching current ripple in the Input Inductor power factor) property as the conventional Boost converter is present with a magnitude at least twice the average value operating with discontinuous Inductor current mode, but of the Input current. High switching frequency and addi- with continuous Input Inductor current. Thus, the proposed tional filtering are required to reduce harmonic distortion topology has much lower Input harmonics and much better to meet the harmonic standards, and therefore to achieve EM1 performance than the conventional Boost converter. a high Input power factor. Neither the conventional DICM By using coupled Inductor technique, the Input Inductor Boost converter nor the DICM Buck-boost converter is op- current ripple can be even dumped into another winding. timal. They reduce the overall efficiency of the power factor Ripple free Input Inductor current is thus achieved. There- correction circuit with an increase in size, weight and cost. fore, the high frequency harmonic distortion can be avoided. The Input filter is not easy to design for the conventional The low frequency Input current ~~veform distortion is ana- Boost converter. If the filter is large, the Input current will lyzed. Simulation results are presented and compared with have a phase delay and result in a low power factor. If the the conventional Boost converter operating in discontinu- filter is Small, the ac line current will be very noisy and 011s conduction mode. Compared to the well Cuk thus generate high EM1(7, 81. Thus, several authors pro- and Sepic converters, the proposed Boost topology has the posed interleaving technology(9, 101 which parallels several advantages of lower switch voltage stress, lower switch cur- stages of Boost converters with one common Input Inductor rent stress and lower voltage stress on capacitor c,. Tile to achieve high power factor and continuous Input induc- theoretical prediction is verified experimentally. tor current. The harmonics are decreased and the EM1 is improved. Other methods such as variable frequency con- trol are suggested to decrease the harmonics and to improve

  • Input Inductor current for unity power factor operation
    PESC Record. 27th Annual IEEE Power Electronics Specialists Conference, 1
    Co-Authors: Jing Wang, William G. Dunford, K. Mauch
    Abstract:

    A fixed frequency, fixed duty cycle boost converter with continuous Input Inductor current for unity power factor operation is introduced in this paper. The proposed boost converter has the same "voltage follower" (unity power factor) property as the conventional boost converter operating with discontinuous Inductor current mode, but with continuous Input Inductor current. Thus, the proposed topology has much lower Input harmonics and much better EMI performance than the conventional boost converter. By using the coupled Inductor technique, the Input Inductor current ripple can be even dumped into another winding. Ripple free Input Inductor current is thus achieved. Therefore, the high frequency harmonic distortion can be avoided. The low frequency Input current waveform distortion is analyzed. Simulation results are presented and compared with the conventional boost converter operating in discontinuous conduction mode. Compared to the well known Cuk and Sepic converters, the proposed boost topology has the advantages of lower switch voltage stress, lower switch current stress and lower voltage stress on capacitor C/sub s/. The theoretical prediction is verified experimentally.

  • A comparison between two proposed boost topologies and conventional topologies for power factor correction
    IAS '96. Conference Record of the 1996 IEEE Industry Applications Conference Thirty-First IAS Annual Meeting, 1
    Co-Authors: Jing Wang, William G. Dunford, K. Mauch
    Abstract:

    A modified boost power converter with an extra LC branch paralleled with the active switch has been proved to have the same "voltage follower" property as the conventional boost power converter operating in discontinuous Inductor current mode (DICM) In this paper, a new modified boost power converter which has an extra LC branch paralleled with the passive switch is proposed. It is proved that the new modified boost topology has continuous Input Inductor current when it operates in the DICM. By using coupled Inductor techniques, the Input Inductor current can be made ripple free when it operates in the DICM. It is proved that the new modified power converter can retain the "voltage follower" property with any coupling coefficient value. A comparison between the new modified boost power converter, the existing modified boost power converter, conventional boost, the Cuk and Sepic power converters used in power factor correction is presented. Several advantages are found in the two proposed boost topologies. The differences between the two proposed boost topologies are also presented. The predicted theory is verified experimentally.

Jacek Rabkowski - One of the best experts on this subject based on the ideXlab platform.

  • High-Frequency SiC-Based Inverters With Input Stages Based on Quasi-Z-Source and Boost Topologies—Experimental Comparison
    IEEE Transactions on Power Electronics, 2019
    Co-Authors: Kornel Wolski, Mariusz Zdanowski, Jacek Rabkowski
    Abstract:

    This paper contains a comparison between three topologies of a three-phase two-level inverter: A quasi-Z-source inverter (qZSI), a voltage-source inverter with a boost converter and a voltage-source inverter with an interleaved boost converter. experimental results obtained from laboratory tests of equivalent 6-kW 100-kHz inverters based on SiC mosfet s and Schottky diodes are provided. The following parameters are compared: Quality of Input Inductor current and output phase voltage as well as total power losses in the inverters. The results for these parameters are obtained for Input voltage ranging from 325 V to almost 600 V (where feasible), for two sets of equivalent modulation methods (two regular methods and two reduced-loss methods), for a couple of characteristic values of deadtime and for the operation both at the maximum value of modulation index and at equal values of voltage across the inverter bridge. Results of the experiments show that the qZSI topology may, at certain conditions, surpass the traditional two-stage inverter topologies in the areas of Input Inductor current quality, output voltage quality and also power losses (at high values of Input voltage). What is needed to obtain that is a careful examination of operating conditions, applied modulation method and deadtime value.

  • SiC-based three-phase Quasi-Z-Source Inverter versus the two-stage topology - a comparison
    2018 International Power Electronics Conference (IPEC-Niigata 2018 -ECCE Asia), 2018
    Co-Authors: Kornel Wolski, Mariusz Zdanowski, Jacek Rabkowski
    Abstract:

    The paper presents an in-depth experimental comparative study between a three-phase Quasi-Z-Source Inverter (qZSI) and a Boost Converter with Voltage-Source Inverter (BC+VSI). Both converters obtain identical output phase voltage value of 230 V RMS from DC Input voltage in range of 400 V ÷ 550 V at a similar value of Input Inductor current ripple. The quality factors investigated are: power losses as well as both Input Inductor current and output voltage quality (considering both low- and high-frequency harmonics). Moreover, four variants of modulation methods are investigated. At switching frequency of 100 kHz results of experiments using SiC-based 6-kW laboratory models show that at identical conditions the BC+VSI configuration has lower losses and better quality of the output voltage, while qZSI has better quality of the Input Inductor current.