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1
Saasaa, Raed. "A single-stage interleaved resonant power factor correction converter." Thesis, University of British Columbia, 2016. http://hdl.handle.net/2429/59199.
Full textAbstract:
Applications requiring DC voltages vary widely, from low power, such as LED lighting, to high power, as in industrial motor drives and battery chargers. Accordingly, a unified power architecture for all applications is not practical for efficiency, size and cost optimization. The use of LED lighting system became popular due to its many advantages. The new outdoor applications such as street and flood lighting require high power (i.e. >200 W) in contrast to the low power existing LED drivers. Generally, the conventional architecture of AC/DC converters consists of two main stages; The first is current-shaping stage to improve PF and the second is to provide isolation and tight regulation over the output voltage. Recently, the research on AC/DC converters has focused on optimizing the converter design to be more reliable and efficient for low and medium power applications. Specifically, techniques have been proposed to eliminate the DC output bus electrolytic capacitor by introducing auxiliary DC/DC converter. On the other hand, the integrated converters were deployed by many researchers to decrease the number of switches, facilitate the controller design, and improve the efficiency. This thesis presents a novel single-stage AC/DC converter that can achieve high power factor with reduced switching losses for semiconductor devices. The topology is derived by integrating the interleaved boost-type PFC and full bridge LLC resonant converters. Due to interleaving at the input, the converter exhibits less input current ripple compared to the existing topologies. Therefore, it is suitable for applications up to approximately 500 W. A detailed analysis of the operation modes is presented. Also, a 350–W prototype is designed to verify the effectiveness of the topology.Applied Science, Faculty of
Engineering, School of (Okanagan)
Graduate
2
Daniele, Matteo. "A single-stage power factor corrected AC/DC converter." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape17/PQDD_0018/MQ39474.pdf.
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Qian, Jinrong. "Advanced Single-Stage Power Factor Correction Techniques." Diss., Virginia Tech, 1997. http://hdl.handle.net/10919/30773.
Full textAbstract:
Five new single-stage power factor correction (PFC) techniques are developed for single-phase applications. These converters are: Integrated single-stage PFC converters, voltage source charge pump power factor correction (VS-CPPFC) converters, current source CPPFC converters, combined voltage source current source (VSCS) CPPFC converters, and continuous input current (CIC) CPPFC converters.
Integrated single-stage PFC converters are first developed, which combine the PFC converter with a DC/DC converter into a single-stage converter. DC bus voltage stress at light load for the single-stage PFC converters are analyzed. DC bus voltage feedback concept is proposed to reduce the DC bus voltage stress at light load. The principle of operations of proposed converters are presented, implemented and evaluated. The experimental results verify the theoretical analysis.
VS-CPPFC technique use a capacitor in series with a high frequency voltage source to achieve the PFC function. In this way, the input inductor is eliminated. VS-CPPFC AC/DC converters are developed, and their performance is evaluated. VS-CPPFC electronic ballasts with and without dimming function are also presented. The average lamp current control with duty ratio modulation is developed so that the lamp operates in constant power with a low crest factor over the line variation. The experimental results verify the CPPFC concept.
CS-CPPFC technique employs a capacitor in parallel with a high frequency current source to obtain the PFC function. The unity power factor condition and principle of operation are analyzed. By doing so, the switch has less switching current stress, and deals only with the resonant inductor current. Design considerations and experimental results of the CS-CPPFC electronic ballast are presented.
VSCS-CPPFC technique integrates the VS-CPPFC with the CS-CPPFC converters. The circuit derivation, unity power factor condition and design considerations are presented. The developed VSCS-CPPFC converters has constant lamp operation, low crest factor with a high power factor even without any feedback control.
CIC-CPPFC technique is developed by inserting a small inductor in series with the line rectifier for the conceptual VS-CPPFC, CS-CPPFC and VSCS-CPPFC circuits. The circuit derivation and its unity power factor condition are discussed. The input current can be designed to be continuous, and a small line input filter can be used. The circulating current in the resonant tank and the switching current stress are minimized. The average lamp current control with switching frequency modulation is developed, so the developed electronic ballast operates in constant power, low crest factor. The developed CIC-CPPFC electronic ballast has features of low line input current harmonics, constant lamp power, low crest factor, continuous input current, low DC bus voltage stress, small circulating current and switching current stress over a wide range of line input voltage.Ph. D.
4
Ismail, Nasser. "A single stage full bridge power factor corrected AC/DC converter." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq26004.pdf.
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Lord, Edward Michael. "Single-stage power factor correction converter topologies for low power off-line applications." Thesis, University of Edinburgh, 2004. http://hdl.handle.net/1842/15234.
Full textAbstract:
Since January 2001 it has been necessary for equipment connected to the low voltage public distribution network in Europe and Japan to comply with IEC 61000-3-2. The regulation IEC 61000-3-2 specifies the level of current that can be drawn for particular harmonics. Much equipment today is fitted with a Switch Mode Power Supply (SMPS) at its input to interface between the line voltage and internal low voltage electronics. This SMPS must not only convert the line voltage, but also ensure that the input current to the device meets the IEC regulations. To meet these regulations two methods are normally used, passive filtering using a large filter inductor or a boost converter cascaded with the main DC/DC SMPS converter with isolation. To try and reduce component count, cost and increase efficiency many new single-stage Power Factor Correction (PFC) topologies have been proposed. In a single-stage topology the output voltage regulation and meeting IEC 61000-3-2 are combined into a single power stage. Unfortunately very little is known about the behaviour or performance of these single-stage topologies. In this thesis two of the more promising single-stage topologies, the bi-forward and CS S2PFC converters are investigated further. A new topology using a low frequency switch (LFSPFC) is introduced. The topologies are analysed investigating input current shape and harmonic content, voltage variation on bulk capacitance and component stresses. Simulation in PSpice is used to confirm circuit operation. Four 150W output power experimental circuits were built: bi-forward converter, CS S2PFC converter, passive filtering cascaded with a forward converter and a boost pre-regulator cascaded with a forward converter. The converters operate from universal input voltage and have outputs at 5V and 12V. A 100W test circuit was built for the LFSPFC operating from 230V input voltage and with an output of 5V. Experimental results are presented showing circuit behaviour and performance of the bi-forward, CS S2PFC and LFSPFC converters. The bi-forward and CS S2PFC converters are compared to the passive filter and boost converter cascaded with a forward converter. It is demonstrated that neither of these single-stage topologies is at present a viable replacement for either present method, but the LFSPFC could be a lighter weight and less bulky alternative to passive filtering.
6
Heidinger, Michael [Verfasser], and W. [Akademischer Betreuer] Heering. "Long Life Single Stage PFC/SLC Converter driving LEDs / Michael Heidinger ; Betreuer: W. Heering." Karlsruhe : KIT-Bibliothek, 2019. http://d-nb.info/1195049293/34.
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Rustom, Khalid. "STEADY STATE AND DYNAMIC ANALYSIS AND OPTIMIZATION OF SINGLE-STAGE POWER FACTOR CORRECTION CONVERTERS." Doctoral diss., University of Central Florida, 2007. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2216.
Full textAbstract:
With the increased interest in applying Power Factor Correction (PFC) to off-line AC-DC converters, the field of integrated, single-stage PFC converter development has attracted wide attention. Considering the tens of millions of low-to-medium power supplies manufactured each year for today's rechargeable equipment, the expected reduction in cost by utilizing advanced technologies is significant. To date, only a few single-stage topologies have made it to the market due to the inherit limitations in this structure. The high voltage and current stresses on the components led to reduced efficiency and an increased failure rate. In addition, the component prices tend to increase with increased electrical and thermal requirements, jeopardizing the overarching goal of price reduction. The absence of dedicated control circuitry for each stage complicates the power balance in these converters, often resulting in an oversized bus capacitance. These factors have impeded widespread acceptance of these new techniques by manufacturers, and as such single stage PFC has remained largely a drawing board concept. This dissertation will present an in-depth study of innovative solutions that address these problems directly, rather than proposing more topologies with the same type of issues. The direct energy transfer concept is analyzed and presented as a promising solution for the majority of the single-stage PFC converter limitations. Three topologies are presented and analyzed based on this innovative structure. To complete the picture, the dynamics of a variety of single-stage converters can be analyzed using a proposed switched transformer model.Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering PhD
8
Wang, Kunrong. "High-Frequency Quasi-Single-Stage (QSS) Isolated AC-DC and DC-AC Power Conversion." Diss., Virginia Tech, 1998. http://hdl.handle.net/10919/29394.
Full textAbstract:
The generic concept of quasi-single-stage (QSS) power conversion topology for ac-dc rectification and dc-ac inversion is proposed. The topology is reached by direct cascading and synchronized switching of two variety of buck or two variety of boost switching networks. The family of QSS power converters feature single-stage power processing without a dc-link low-pass filter, a unidirectional pulsating dc-link voltage, soft-switching capability with minimal extra commutation circuitry, simple PWM control, and high efficiency and reliability.
A new soft-switched single-phase QSS bi-directional inverter/rectifier (charger) topology is derived based on the QSS power conversion concept. A simple active voltage clamp branch is used to clamp the otherwise high transient voltage on the current-fed ac side, and at the same time, to achieve zero-voltage-switching (ZVS) for the switches in the output side bridge. Seamless four-quadrant operation in the inverter mode, and rectifier operation with unity power factor in the charger (rectifier) mode are realized with the proposed uni-polar center-aligned PWM scheme. Single-stage power conversion, standard half-bridge connection of devices, soft-switching for all the power devices, low conduction loss, simple center-aligned PWM control, and high reliability and efficiency are among its salient features. Experimental results on a 3 kVA bi-directional inverter/rectifier prototype validate the reliable operation of the circuit. Other single-phase and three-phase QSS bi-directional inverters/rectifiers can be easily derived as topological extensions of the basic QSS bi-directional inverter/rectifier.
A new QSS isolated three-phase zero-voltage/zero-current-switching (ZVZCS) buck PWM rectifier for high-power off-line applications is also proposed. It consists of a three-phase buck bridge switching under zero current and a phase-shift-controlled full-bridge with ZVZCS, while no intermediate dc-link is involved. Input power and displacement factor control, input current shaping, tight output voltage regulation, high-frequency transformer isolation, and soft-switching for all the power devices are realized in a unified single stage. Because of ZVZCS and single-stage power conversion, it can operate at high switching frequency while maintaining reliable operation and achieving higher efficiency than standard two-stage approaches. A family of isolated ZVZCS buck rectifiers are obtained by incorporating various ZVZCS schemes for full-bridge dc-dc converters into the basic QSS isolated buck rectifier topology. Experimental and simulation results substantiate the reliable operation and high efficiency of selected topologies.
The concept of charge control (or instantaneous average current control) of three-phase buck PWM rectifiers is introduced. It controls precisely the average input phase currents to track the input phase voltages by sensing and integrating only the dc rail current, realizes six-step PWM, and features simple implementation, fast dynamic response, excellent noise immunity, and is easy to realize with analog circuitry or to integrate. One particular merit of the scheme is its capability to correct any duty-cycle distortion incurred on only one of the two active duty-cycles which often happens in the soft-switched buck rectifiers, another merit is the smooth transition of the input currents between the 60o sectors. Simulation and preliminary experimental results show that smooth operations and high quality sinusoidal input currents in the full line cycle are achieved with the control scheme.Ph. D.
9
Wen, Hao. "High-Efficiency and High-Frequency Resonant Converter Based Single-Stage Soft-Switching Isolated Inverter Design and Optimization with Gallium-Nitride (GaN)." Diss., Virginia Tech, 2021. http://hdl.handle.net/10919/105134.
Full textAbstract:
Isolated inverter can provide galvanic isolation which is necessary for some applications with safety regulations. Traditionally, a two-stage configuration is widely applied with isolated dc-dc stage and a sinusoidal pulse-width-modulated (SPWM) dc-ac stage. However, this two-stage configuration suffers from more components count, more complex control and tend to have lower efficiency and lower power density. Meanwhile, a large dc bus capacitor is needed to attenuate the double line frequency from SPWM for two-stage configuration. Therefore, the single-stage approach including an isolated dc-rectified sine stage and a line frequency unfolder is preferable. Since the unfolder circuit is at line frequency being almost lossless, the isolated dc-rectified sine stage becomes critical.
However, the relevant research for the single-stage isolated inverter is limited. People either utilize PWM based converter as dc-rectified sine stage with duty cycle adjustment or apply SRC or LLC resonant converter for better soft switching characteristics. For PWM based converter, hard switching restricts the overall inverter efficiency, while for SRC/LLC, enough wide voltage gain range and full range ZVS are the major issues.
This dissertation aims to provide solutions for a high-efficiency, high-frequency resonant converter based single-stage soft-switching isolated inverter design. The LLC and LCLCL resonant converters are applied as the isolated dc-rectified sine stage with variable frequency modulation (VFM). Therefore, the rectified sine wave generation consists of many dc-dc conversion with different switching frequencies and an efficient dc-rectified sine stage design needs each dc-dc conversion to be with high efficiency.
This dissertation will first propose the optimization methods for LLC converter dc-dc conversion. ZVS models are derived to ensure fully ZVS performance for primary side GaN devices. As a large part in loss breakdown, the optimization for transformer is essential. The LLC converter can achieve above 99% efficiency with proposed optimization approach. Moreover, the channel turn-off energy model is presented for a more accurate loss analysis.
With all the design and optimization considerations, a MHz LLC converter based isolated inverter is designed and a hybrid modulation method is proposed, which includes full bridge (FB) VFM for output high line region and half bridge (HB) VFM for output low line region. By changing from FB to HB, the output voltage gain is reduced to half to have a wider voltage gain range. However, the total harmonic distortion (THD) of output voltage at light load will be impacted since the voltage gain will be higher with lighter load at the maximum switching frequency.
A MHz LCLCL converter based isolated inverter is proposed for a better output voltage THD at light load conditions. The paralleled LC inside the LCLCL resonant tank can naturally create a zero voltage gain point at their resonant frequency, which shows superior performance for rectified sine wave generation. Besides the better THD performance, the LCLCL converter based isolated inverter also features for easier control, better ZVS performance and narrower switching frequency range.
Meanwhile, the LCLCL based inverter topology has bi-directional power flow capability as well. With variable frequency modulation for ac-dc, this topology is still a single-stage solution compared to the traditional two-stage solution including PFC + LLC configuration.Doctor of Philosophy
Inverters can convert dc voltage to ac voltage and typically people use two-stage approach with isolated dc-dc stage and dc-ac stage. However, this two-stage configuration suffers from more components count, more complex control and tend to have lower efficiency and lower power density. Therefore, the single-stage solution with dc-rectified sine wave stage and a line frequency unfolder becomes appealing. The unfolder circuit is to unfold the rectifier sine wave to an ac sine wave at the output. Since the unfolder is at line frequency and can be considered lossless, the key design is for the dc-rectified sine stage. The resonant converter featured for soft switching seems to be a good candidate. However, the inverter needs soft switching for the whole range and an enough wide voltage gain, which makes the design difficult, especially the target is high efficiency for the overall inverter. This dissertation aims to provide solutions for a high-efficiency, high-frequency resonant converter based single-stage soft-switching isolated inverter design. The LLC and LCLCL resonant converters are applied as the isolated dc-rectified sine stage with variable frequency modulation (VFM). Therefore, the rectified sine wave generation consists of many dc-dc conversion with different switching frequencies and an efficient dc-rectified sine stage design needs each dc-dc conversion to be with high efficiency. The design considerations and optimization methods for the LLC dc-dc conversion are firstly investigated. Based on these approaches, a MHz LLC converter based isolated inverter is designed with proposed hybrid modulation method. To further improve the light load performance, a MHz LCLCL converter based isolated inverter topology is proposed. The paralleled LC inside the LCLCL resonant tank can naturally create a zero voltage gain point which shows superior characteristics for rectified sine wave generation. Moreover, the LCLCL resonant converter based topology has bi-directional capability as well so it can work well for ac voltage to dc voltage conversion.
10
Li, Heng-Yi, and 李恆毅. "Single-Stage Parallel Boost-Flyback Converter." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/16540659760349787865.
Full textAbstract:
博士國立交通大學
電控工程研究所
98
It is known that part of the power is repeatedly processed or recycled in the conventional single-stage (S2) and two-stage AC/DC converters. Therefore, a novel S2 scheme is presented based on the parallel power factor correction (PPFC). In the scheme, the boost-flyback semi-stage containing boost cell and flyback cell is used to generate two energy processing path. The main input power flow stream is processed only by flyback cell and output to load directly. And the remaining input power stream is stored in bulk capacitor by boost cell and then transferred by DC/DC semi-stage to output for regulating output power. Theoretical analysis shows that as the boost cell and flyback cell operate in DCM and duty ratio and switching frequency are kept constant, using smaller boost inductor can result in higher power factor. Since most power is processed only once, the power conversion efficiency is improved and the current stress of control switch is reduced. The scheme can also be applied to other conversion circuits by replacing flyback cell and DC/DC semi-stage with other topology. Taking the parallel boost-flyback-flyback converter as an example, the operation modes and average switching period signals are analyzed, the key parameters of power distribution and bulk capacitor voltage, design equations, and design procedure are also presented. By follow-ing the procedure, an 80 W universal prototype has been built and tested. The experimental results show that at the worst condition of operation range the measured line harmonic current complies with the IEC61000-3-2 class D limits, the maximum bulk capacitor voltage is about 415.4 V, and the maximum efficiency is about 85.8%. It can be seen from the converter analysis, there are two operation modes in half line cycle and the duty ratio varied with line phase to keep output constant in one mode. The small sig-nal transfer function of the converter with variable duty ratio cannot be validated with con-ventional frequency response measurement. Hence, the small-signal models of operation modes are built and the compensator design at the boundary of modes is presented, the dy-namic response has small steady state error, fast rise time, and heavily damping within opera-tion range. Finally, the dynamic model and designed compensator of parallel converter are verified in time domain by simulation and experiment.
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Chin, Chun-liang, and 景淳良. "A Single-Stage Active-Clamp Forward Converter A Single-Stage Active-Clamp Forward Converter Employing Two Transformers." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/29523336939009639002.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
102
This thesis presents a single-stage AC-to-DC power converter, which consists of a boost-type power factor corrector (PFC) and a two-transformer active-clamp forward converter. The PFC stage adopts the voltage-follower control under discontinuous conduction mode. It helps reduce the volume of the boost inductor. The current control loop is not required to reduce the circuit design complexity. By utilizing separate transformers, the proposed converter features zero-voltage switching and good line regulation over a wide range of the input voltage. The output power can be shared by two transformers to reduce their volumes and the stresses of components at secondary side. This allows high power density design. The operating principle of this single-stage power converter has been analyzed, described and discussed in detail. The simulaton softwares, Mathcade and PSIM, are applied for circuit design. The experimental results with an input voltage of 115 Vac and an output of 19 V/140 W reveal a maximum efficiency of 85% and a maximum power factor of 0.99.
12
LEE, CHIN-PING, and 李金屏. "Single-Stage Converter Power LED Lighting Applications." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/vbee54.
Full textAbstract:
碩士臺北城市科技大學
資訊應用產業碩士專班
106
ABSTRACT In recent years, LED lighting has gradually been widely used in lighting products, while the traditional incandescent and fluorescent lamps are slowly being replaced by the trend. We uses a single-stage power converter in LED lighting, with small size, high power factor, economical, energy-saving carbon reduction and other advantages. The single-stage converter power supply provides high-precision constant-current mode that reliably stabilizes the current on the LED and allows for uniform LED brightness for improved light quality.
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Wei-ChengChen and 陳威呈. "Single-Stage Three-Phase CCM Wind-Power Converter." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/v6gn8t.
Full textAbstract:
碩士國立成功大學
電機工程學系碩博士班
101
This thesis presents a single-stage three-phase CCM wind-power converter. In order to achieve both maximum-power-point-tracking (MPPT) and three-phase power-factor-correction (PFC) mechanisms, two stages are employed in the conventional wind energy conversion system (WECS). However, the two-stage system results in some drawbacks, including larger volume, more components, higher circuit cost, more complicated control scheme and lower system efficiency. Therefore, the proposed converter of this thesis is developed to avoid these problems and increase the electromechanical conversion efficiency of the wind turbine generator (WTG), the MPPT and three-phase PFC mechanisms are employed simultaneously. In the proposed circuit, a three-phase PFC converter and an average-current-mode control (ACMC) scheme are utilized to improve the power factor of the converter for the WEC. Besides, according to the characteristics of the WTG, the output voltage, current, and power of the WTG can be operated at MPP for each wind speed by using the ACMC scheme and subtracting amplifier. In this thesis, a wind turbine emulator (WTE) is used as the AC source for the proposed circuit with the emulated wind speed ranging from 5m/s to 9m/s. The lowest and highest powers at MPP of the WTE are 185W and 1079W, respectively. Finally, a prototype circuit of the single-stage three-phase CCM wind-power converter is built to verify the performances using MPPT and three-phase PFC mechanisms.
14
Cheng, Sheng-Hung, and 鄭聖弘. "Single-stage SEPIC Converter for Driving Lighting LED Lamps." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/27570733459103225341.
Full textAbstract:
碩士中原大學
電機工程研究所
95
Single-stage boost-type DCM PFC converters are commonly used in low-power lighting applications. The peak source current can be shaped automatically to follow the source voltage as long as the boost inductor is operated in discontinuous conduction mode. However, high DC bus voltage may cause over voltage stresses on the switching devices. In this thesis, a CCM SEPIC PFC converter is studied for driving lighting LED lamps. High power factor, high efficiency, and LED current regulation can be achieved with the proposed SEPIC converter. The operating principles and design considerations for the proposed SEPIC PFC converter are analyzed and discussed in detail. A laboratory prototype has been built and tested to verify the feasibility of the proposed scheme.
15
Chen, Guan-Ying, and 陳冠穎. "A Novel Single-stage Single-phase AC to Three-phase AC Converter." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/7dv95n.
Full textAbstract:
碩士國立虎尾科技大學
電機工程研究所
100
This thesis proposes a novel single-stage single-phase AC to three-phase AC converter. Based on a zero vector technique, the proposed converter combines a single-phase full-bridge with three-phase full-bridge to form a single-stage circuit structure. The converter has unity power factor and sinusoidal input current in input side. Adjustable amplitude and frequency of three-phase current source are in output side. The proposed converter consists of eight power switches, one capacitor, one boost inductor and three output inductors. It’s worth mentioning that ten switches of the traditional converter can reduce to eight, and this can reduce cost and improve efficiency obviously. Besides, general solution of the switching duty ratio is obtained by using the state space averaging technique. Furthermore, employing the three-phase dead-band control can decrease the ratio of 1/3 times switching number. Consequently, this reduce the switching loss, and improves efficiency of the converter. In the control circuit, both VisSim simulation and DSP TMS320F2812 are employed to finish digital control for power factor correction of the input side and feedback control of the output side. Finally, some experiment results are presented to verify the feasibility of the proposed converter.
16
Lin, Huan-Kuei, and 林桓槶. "A Study of Single-Stage Single-Switch Parallel High Power Factor Correction Converter." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/19797370705148131624.
Full textAbstract:
碩士國立臺灣海洋大學
電機工程學系
94
ABSTRACT In this thesis, the DPT(Direct Power Transfer) concept is use to compose the parallel power transfer topology. By adding a secondary winding to the inductor of boost power factor correction converter, this topology will provide another power flow path, some portion power directly transferred to the load to achieve high power factor and improve the efficiency. Some portion power transferred to the load through DC/DC converter achieve tight output voltage regulation. Introducing single-stage single-switch topology reduce the quantity of power switch and simplify the control scheme. To prove the practicality and performance of the circuit, the thesis will be verified in coordination with textbooks, formula deriving and the computer simulation of IsSpice.
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Yeh, Yo-Sheng, and 葉侑昇. "Single-Stage Soft Switching Flyback Converter with Power Factor Correction." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/77640066543534477254.
Full textAbstract:
碩士國立高雄應用科技大學
電機工程系
97
The purpose of this thesis is to design and implement a single-stage soft switching flyback converter with power factor correction. The active clamp flyback converter has many advantages such as high efficiency, lower Electromagnetic Interference. This thesis applies the advantages of active clamp flyback converter to single-stage power factor correction AC/DC converter. This converter can reduce the conduction loss, switching loss and EMI, to achieve the goal of increasing the efficiency, power factor correction and reducing the cost. The operation principle of this single-stage power factor correction AC/DC converter is described and analyzed. Finally, a prototype converter is implemented. The maximum efficiency of this converter is 84.5% at half load and 83.5% at full load. The power factor is above 0.88.
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Hsiao, Li-yang, and 蕭立揚. "Single-Stage PFC Flyback Converter with Low Output Voltage Ripple." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/rk83qj.
Full textAbstract:
碩士國立中山大學
電機工程學系研究所
97
An auxiliary winding with an associated capacitor is added on the single-stage power factor corrector (PFC) based on fly-back conversion to reduce the ripple on the dc output voltage. The associated capacitor takes out partial energy at every switching cycle from the fly-back conversion and releases the stored energy to the load at the valley of the rectified line voltage. The negative effect of such an approach is that the converter does not draw a current from the AC line at the lower voltage near zero crossing, leading to deterioration in the power factor. This thesis analyzes how an auxiliary winding affects the voltage of the associated capacitor, which in turn changes the cut-in angle of the input current and thus the power factor of the AC source. To facilitate the implementation, the fly-back converter is operated at the boundary conduction mode (BCM). A design example is given for the 24 V, 48 W load, based on the derived equations. The laboratory circuit is built and tested to verify the computer simulations and analytical predictions. The experimental results confirm the circuit analyses on the converter performances.
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Hsiao, Ho-Pu, and 蕭賀璞. "Development of the Novel Half-Bridge Single-Stage Power Converter." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/k8v78s.
Full textAbstract:
碩士國立臺北科技大學
電力電子產業研發碩士專班
95
This thesis discusses how to transform two-stage power converter to single-stage power converter by component placement and synchronous switching technology. Moreover, the novel half-bridge single-stage power converter combines a half-bridge AC/DC PFC converter with a half-bridge DC/DC converter by these methods. In general, the main advantages of two-stage power converter are high power factor, low input current harmonics and so on. However, it has some disadvantages, including (1) the poor efficiency due to twice power process; (2) the two-stage structure needing extra controller, larger area of circuit and more switch components. According to the viewpoint of cost, this two-stage PFC converter is unsuitable to be used in low-power applications. In order to improve these disadvantages, the single-stage power converter is development. The novel half-bridge single-stage power converter proposed in this thesis has inherent gift of great power factor correction function, even the PFC inductor operates in DCM. Therefore, the original two controllers can be integrated into one single controller, and it still has great power factor correction function. First of all, the effect of the bulk capacitor due to load variation and how to solve this problem are discussed in this thesis. The operation and design of the proposed single-stage converter are then analyzed. Finally, experimental results show good conformation with the theoretical analysis.
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Lo, Chien-Yu, and 駱建宇. "Design and Implementation of Half-Bridge Single-Stage Power Converter." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/448dg3.
Full textAbstract:
碩士國立臺北科技大學
電力電子產業研發碩士專班
96
A novel current-fed half-bridge single-stage power converter is proposed in this thesis, which is a combination of one half-bridge PFC and one half-bridge dc/dc converter to reduce control structure and the number of switches. When PFC operating in discontinuous conduction mode and fixed switching frequency, there is power factor correction in nature, and the control process is simplified. Further, compared to voltage-fed single-stage power converter, the proposed current-fed converter is advantageous to eliminate the output filter inductor. First, this thesis recommends the differences between the voltage-fed converter and the current-fed converter, then the operation of the current-fed single-stage power converter is analyzed. Finally, make a circuit of 100 watts in order to prove the principle and theory accord.
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Chiang, Xian-Yuan, and 江顯元. "Design and Implementation of FPGA-Based Single-Stage Flyback Converter." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/97c7km.
Full textAbstract:
碩士國立臺北科技大學
電力電子產業研發碩士專班
96
The objective of this thesis is to design and implement an FPGA-based single-stage flyback converter with power factor correction. Based upon the well known component placement and synchronous switching methods, the single-stage flyback converter with PFC is derived from its two-stage counterpart. The advantages of the designed and implemented single stage flyback converter with PFC include reduction of power devices and the related driver. This kind of converter becomes very promising for low power applications. The controller is realized using FPGA to provide programmable capability and digital control. The design specifications are: input voltage = 110 V/AC, 60 Hz, output voltage = 12 V/DC and the rated output power = 40 W. The small-signal model is derived for digital controller design. The derived model is confirmed by simulation and realized by FPGA. Experimental results show that the output voltage can be well regulated while keeping the input power factor greater than 95%. These results confirm the design and implementation.
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CHIANG, MING-CHUN, and 江明駿. "Design and Implementation of a Single-Stage Full-Bridge Converter." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/gze45y.
Full textAbstract:
碩士國立臺北科技大學
電機工程系電力電子產業碩士專班
108
The purpose of this thesis is to design and implement a single-stage full-bridge converter. The system uses a full-bridge converter as the main architecture, combined with a dual power factor correction inductor and interleaved technology, so that the converter has excellent power factor correction capability. In addition, all switches have zero voltage conduction characteristics and the reverse recovery current of the power diode can be improved. Therefore, the switching losses and reverse recovery losses can be reduced, that is system efficiency can be higher. This thesis uses voltage loop control for output stable regulation also can be achieved. In this thesis, the microcontroller TMS320D28035 produced by Texas Instruments is used as the control core to realize the designed controller and voltage loop control method to verify the correctness and feasibility of the implemented single-stage full-bridge converter and the associated design analysis. The experimental results include input voltage AC 110V,output voltage DC48V and maximum output power500W. The experimental results show that the harmonic current meets IEC61000-3-2 Class D standard, the power factor can reach 0.98 under full load condition, and maximum efficiency is 91.24%.
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Dharmarajan, Vimala. "Three-level soft-switched DC-to-DC converter and single-phase, single-stage, three-level AC-to-DC converter." Thesis, 2006. http://hdl.handle.net/1828/2335.
Full textAbstract:
This thesis proposes a three-level DC-to-DC converter with capacitive output filter and its extension to single-phase, single-stage, three-level AC-to-DC converter with capacitive output filter. The AC-to-DC converter integrates a three-level boost converter operating in discontinuous conduction mode (DCM) and a three-level half-bridge DC-to-DC converter with capacitive output filter.
The steady-state operation of the DC-to-DC converter and AC-to-DC converter with capacitive output filter are studied with phase-shifted gating scheme. The three-level topology reduces the voltage rating of the switches to half of the input voltage. Soft-switching is achieved for switches at different load and input voltage conditions. Boost section of the AC-to-DC converter achieves automatic power factor correction (PFC). At reduced load and higher input voltage conditions, the line current Total Harmonic Distortion (THD) increases with phase-shifted gating scheme. The THD has been reduced by using a complementary PWM gating control in the AC-to-DC converter.
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Ismail, Nasser. "A single stage full bridge power factor corrected AC/DC converter." Thesis, 1996. http://spectrum.library.concordia.ca/193/1/MQ26004.pdf.
Full textAbstract:
Conventional single phase AC/DC converters use a two stage power configuration to provide a regulated DC power supply at high input power factor. Elimination of one of these stages can reduce the cost, weight, size, complexity and increase the overall reliability of this converter. This thesis proposes a single stage power factor correction converter circuit. This proposed converter circuit uses the traditional non-power-factor corrected circuit configuration with only few additional components. These are: an additional winding on the high frequency transformer, a small high frequency inductor and three diodes. The topology allows the output voltage regulation and input current shaping with a single power processing stage and one control chip. In addition, it is shown that this converter can be designed to offer soft switching of the full bridge switches. The operating principles of the proposed converter are discussed and its performance characteristics under steady state conditions are examined. A design procedure is illustrated to select the components of the converter for a 500 W power supply operating at 50 kHz. Theoretical results are verified with simulation and experimental tests on a 500 W laboratory prototype.
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Lai, Wei-hung, and 賴威宏. "Realization of a Single-stage Flyback converter with Power Factor Correction." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/s8239e.
Full textAbstract:
碩士國立臺灣科技大學
電機工程系
99
High-brightness LEDs are energy-saving, cost-effective choices that enable the next generation of lighting applications. Despite large output voltage ripple, single-stage AC-DC conversion is a more attractive solution than two-stage conversion from the stand point of cost and power density. Especially in applications like LED lighting and battery charger. On the other hand, digital power control techniques are rapidly gaining market share as designers increasingly appreciate the advantages that the technology offers over its analog counterpart. In this thesis, the digital control technology for single-stage flyback power factor corrector (PFC) is investigated. Firstly, two analog single-stage flyback PFC circuits are built using the L6561 and TL494 PWM control ICs, respectively. Next, using the same power stage, a digital control algorithm using the Microchip dsPIC30F2020 digital signal controller (DSC) is developed. Finally, experimental results of these three single-stage flyback PFC circuits will be provided to validate the correctness of the proposed digital control algorithm. According to the experimental results, all the three presented PFC circuits can achieve efficiency higher than 84% and power factor higher than 90%.
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Yeh, Yung-Sheng, and 葉永盛. "Analysis and Implementation of Single Stage Parallel Boost-Flyback-Flyback Converter." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/15638364135657152615.
Full textAbstract:
碩士國立交通大學
電機學院碩士在職專班電機與控制組
98
This paper proposes a single-stage boost-flyback-flyback parallel AC/DC converter with single-switch-two-output boost-flyback converter theory. One is the boost-flyback semi-stage that improves power factor and other one is flyback semi-stage that improves the regulation performance and increase efficiency. The proposed converter includes three operation modes- continuous current mode, boundary mode and discontinuous current mode. Various modes would result in various effect on efficiency and power factor under various input voltages and various output loads. The calculation result from MATHCAD and the experimental results demonstrate that the proposed boost-flyback-flyback converter yields higher efficiency and higher power factor than traditional flyback converter.
27
Li, Zhu-Rong, and 李竹容. "Analysis and Design of Single-Stage AC/DC LLC Resonant Converter." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/98101607642864596172.
Full textAbstract:
碩士國立臺灣大學
電子工程學研究所
97
A conventional power supply was designed with two stages, the former stage function as a power factor corrector (PFC), and the latter stage is a DC/DC converter which regulates the output voltage of the system. However, the cost and energy conversion efficiency of the two-stage system is higher than a single-stage one. LLC resonant converters not only have characteristics of high efficiency and low noise but also are easy to control. This circuit topology is becoming more and more widely used in application of power conversion. The duty cycle of both MOSFETs of a LLC converter is 50% that is different from a traditional PWM converter. The output regulation is control by modulation of frequency, in the ZVS region, the energy from primary side to load increases as the switching frequency decreases. In this thesis, a single-stage LLC resonant converter which combines a boost-type PFC cell and an LLC resonant DC/DC cell is proposed. The control method of it is the same as a conventional LLC resonant converter that regulate output voltage by modulating switching frequency. When the load increases, the switching frequency decreases so that the LLC gain increases and more energy can be transferred by input inductor due to longer charging time. The proposed circuit could not only reduce components and circuit size but also increase the power conversion efficiency. It has no control of the voltage of the DC-bus capacitor because there is no separate converter that can control it as there is in a two-stage converter. The capacitor voltage is dependent on the energy equilibrium established between the energy flowing into the capacitor from the input inductor and the energy flowing out of the capacitor and transferred to the output. Therefore, the characteristics of LLC tank are investigated and a new LLC design consideration is proposed, which insures the DC-bus capacitor voltage can be kept in a tolerable region. Finally, an experimental circuit is implemented to verify the analysis.
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Varajão, Diogo André Cerqueira Pinto Bezerra. "Single-stage, bidirectional AC-DC matrix converter for energy storage systems." Doctoral thesis, 2018. https://hdl.handle.net/10216/115552.
Full text
29
Varajão, Diogo André Cerqueira Pinto Bezerra. "Single-stage, bidirectional AC-DC matrix converter for energy storage systems." Tese, 2018. https://hdl.handle.net/10216/115552.
Full text
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HuangYen-Chang and 黃彥彰. "Analysis and Implementation of A Single-Stage High Power-Factor Converter." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/22848293184799004496.
Full textAbstract:
碩士崑山科技大學
電機工程研究所
95
A single-stage high power-factor converter combined by the buck-boost and flyback converters is studied in this thesis. The combined process of the converter is presented. The converter exhibits high power-factor inherently without external current control when it operates under DCM+DCM mode. Moreover, the high voltage stress of the bulk capacitor does not exist. Based on the loss-free-resistor (LFR) model, the state-space averaging method, harmonics balance method and TL-model method are used to obtain the dc values, voltage ripples and phase angle shift for the bulk capacitor and output voltage in the steady-state analysis.The results of IsSpice simulation are used to verify theoretical analysis. The two-time scale averaging method and current injected equivalent circuit approach are used to derived the small signal model and obtain the coincide results. The theoretical results are verified by the experimental measurements of dynamic signal analyzer (Agilent 35670A).Eventually, a controller is designed to eliminate the effect of the variations of line voltage and load on the output voltage. A prototype of the converter with input voltage 110 Vrms, output voltage 48 V and maximal power 100 W is implemented. The performances of high power-factor, low bulk capacitor voltage stress and well output voltage regulation are verified by experimental measurements.
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Wang, Wei-Jun, and 王偉俊. "Single-Stage Power Factor Correction AC/DC Converter with Valley Switching." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/75711255465947348627.
Full textAbstract:
碩士國立高雄應用科技大學
電機工程系碩士班
95
The purpose of this thesis is to design and implement a single-stage power factor correction AC/DC converter with valley switching. The quasi-resonant flyback converter has many advantages such as high efficiency, lower Electromagnetic Interference. This thesis applies the advantages of quasi-resonant flyback converter to single-stage power factor correction AC/DC converter. This converter can reduce the conduction loss, switching loss and EMI, to achieve the goal of increasing the efficiency 、power factor correction and reducing the cost. The operation principle of this single-stage power factor correction AC/DC converter is described and analyzed. Finally, a prototype converter is implemented. The maximum efficiency of this converter is 81.1% and the maximum power factor is 93.9%.
32
Yu, Ming-Hung, and 游明弘. "Design and Implementation of a Single-Stage Interleaved AC-DC Converter." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/82289156748544487622.
Full textAbstract:
碩士雲林科技大學
電機工程系碩士班
98
This paper presents a single-stage interleaved flyback converter with boundary conduction mode (BCM). By using interleaved technique, the current stress of the semiconductor devices and the ripple current on the input and output side are reduced. Besides, the switching losses of the switching components are also reduced by employing BCM control. In this paper, the PWM model and Loss-Free Resistor (LFR) model are employed to analysis the small-signal model of the converter, and the Bode plots of gain and phase in frequency domain are earned by Mathcad software, which is able to determine the stability of the system and the establishment of closed-loop system of the converter. Finally, simulation and experimental results from a 480W prototype are presented to confirm the effectiveness of the proposed converter.
33
Ke, Yi-Fong, and 柯懿峰. "Implementation of a Half-Bridge Single-Stage Converter Control Using DSP." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/64443f.
Full textAbstract:
碩士國立臺北科技大學
電力電子產業研發碩士專班
95
A single-stage AC/DC converter which is developed using Digital Signal Processor (DSP) to implement a novel control strategy for elevating power factor and efficiency and reducing THD and cost is proposed in this thesis. The single-stage topology is merged from one power factor corrector and one power regulation stage, both the half-bridge structures. The proposed circuit features the reducing of switch number and only one control circuitry. Power factor correction is easily and successfully achieved with the novel DCM control strategy using DSP-TMS320LF-2407 manufactured by TI. Compared to traditional control methods, the proposed is simpler, more flexible to implement higher power factor and efficiency. Experiments are conducted to verify the theoretical analysis.
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Varajão, Diogo André Cerqueira Pinto Bezerra. "Single-stage, bidirectional AC-DC matrix converter for energy storage systems." Tese, 2002. https://repositorio-aberto.up.pt/handle/10216/115552.
Full text
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Chang, Yu-Liang, and 張宇良. "A Single Stage Single Switch Flyback-Forward Converter with PFC and LED Light Source System." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/11130797811002469003.
Full textAbstract:
碩士國立高雄應用科技大學
電機工程系博碩士班
101
This paper proposes a single-stage single-switch Flyback-Forward converter as a LED driver lighting circuit. This structure is an improvement of a typical flyback converter, when the switch is turned on, the energy can be outputted, when the switch is turned off, also energy can be inputted. This structure can improve the typical flyback converter that is only designed for low-to-medium power. Therefore, the output power is up to 150W-200W. Besides, a boost inductor is added in the input of the converter, to make it has the function of power factor correction. This paper will also explore the circuit analysis and design. In order to improve the efficiency of the converter, design a control loop to make the switch zero-current-switching, to reduce switching losses. And design a transformer leakage inductance energy recovery circuit, when the switch turns off, the spike and surge oscillation can be reduced, the leakage inductance energy is stored in the clamp capacitance, so the switch voltage can be reduced. At the next switch turn-on, the energy in the clamp capacitor is recovered to the bulk capacitor. Finally, the converter is verified using IsSpice software and a prototype 150W (36V/4.2A) AC / DC LED driver and lighting circuits are implemented. Use the valley switching and the leakage inductance energy recovery circuit, there is no spike when switching, and the overall efficiency is up to 90%, higher than the efficiency of 85% in the industry. Also it has the function of the power factor correction.
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Lin, Li-Fan, and 林立凡. "Study and Implementation of Single-Stage Single-Switch Boost-Flyback Converter with Power Factor Correction." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/29675628882064308699.
Full textAbstract:
碩士國立臺灣海洋大學
電機工程學系
99
This thesis is focused on the study and implementation of a single-stage boost-flyback converter with Power Factor Correction, using the transformer auxiliary winding of flyback converter in series with the auxiliary energy storage capacitor, place in the between input rectifier and DC link capacitor, as a magnetic switch to drive the boost inductor. Because the converter operate at high frequency, the auxiliary winding will produce a high-frequency pulse-wave source, Significantly improve the quality of input current, and reduce input current harmonics. This architecture offers both power factor correction capability and output voltage regulation characteristics, Also eliminate the problem of current stress on power switch of derivative structure which is caused by component placement method and synchronous switching method. The power factor correction section does not require power switch and control circuit, can reduce costs and improve efficiency. Finally, experimental results are given to confirm the theoretically predicted behavior.
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Su, Ying-Chieh, and 蘇英傑. "Single-Stage Asymmetrical Half-Bridge Power Converter with Synchronous Current-Doubler Rectification." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/87173496615898320519.
Full textAbstract:
碩士中原大學
電機工程研究所
92
This thesis presents the design and implementation of the single-stage high power factor asymmetrical half-bridge converter with synchronous current-doubler rectification. The asymmetrical half-bridge converter has many advantages such as soft switching properties, fewer components, lower voltage across the transformer primary allows a smaller number of primary turns and voltage across the switches is clamped to the input voltage ,and therefore it is suitable for the DC/DC cell. Then boost-type converter use in a PFC cell that operating in discontinus conduction mode has innate of power factor collection without any controller. We employ a synchronous current-doubler-rectification in the secondary winding of the single-stage AC/DC converter to improve efficiency of the converter when operating in low-voltage/high-current conditions. The operation principle and equivalent circuits of the single-stage AC/DC converter in every operating stage have be described and analyzed in detail. Computer simulation using IsSpice has been applied in design and analyzing the single-stage AC/DC converter. Experiment results have verified the theoretical analysis and computer simulation with an input of 110 V (ranged from 90~130V), output of 5V/20A, and maximum efficiency of 81.87 %.
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Lai, Jian-Hong, and 賴建宏. "Design and Implementation of Single-Stage Forward Converter with Power Factor Correction." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/4d7q34.
Full textAbstract:
碩士國立臺北科技大學
電力電子產業研發碩士專班
95
The objective of this thesis is to design and implement single-stage forward converter with power factor correction. Its advantage is to improve power factor and reduce input current harmonics. The power device for power factor correction and DC/DC conversion is merged for the single-stage forward converter and thereby reducing the number of power device and cost. The control IC is NCP1651 of ON Semiconductor. The specifications of the designed converter include 110 V/AC of input and 48 V/DC, 100W of output. Experimental results show that the designed and implemented converter works from no load to fully load. Moreover it is shown that its power factor higher than 95% and efficiency more than 80%. These results verify the theoretical analysis, design and implementation.
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Lai, Chuan-Wen, and 賴景文. "Design and Implementation of single-stage boost converter in wind power system." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/9m2fgk.
Full textAbstract:
碩士國立虎尾科技大學
材料科學與綠色能源工程研究所
96
The present study was aimed at improving the power management system of small-scale wind turbine generator. Pursuant to this objective, a test bench was built to test the output power of small-scale wind turbine generator. We also introduced a new non-inductor type boost switching circuit to the power management system to improve the power transformation efficiency. The test bench was constructed by the PC with data acquisition system, an 180V brush DC motor through the coupling direct drive wind-driven generator, and imitate to electrical load by boost switching circuit. This experiment was performed in constant current, constant resistance, and constant voltage mode through electrical load. We used PC, microchip microcontroller dsPICF4011, Labview software and designed interface circuit to develop data acquisition system. Data acquisition system measured the output power, voltage and current before boost conversion, voltage and current after boost converter of the inductor or non-inductor type boost converter in assigned duty cycle and different motor rotational speed. The experimental results showed that under constant current mode, the inductor or non-inductor type boost converter had the maximum output power when duty cycle at 50%. Under constant current mode, when duty cycle opened lower than 60%, the output power was the same in both test modes. The output power transformation efficiency of inductor type boost converter was better than non-inductor type. When duty cycle opened larger than 60%, the inductor type boost converter had the better output power, and the non-inductor type output power transformation efficiency was better than inductor type. Under constant voltage mode, the output power of inductor and non-inductor type boost converter was the same. When the rotor speed was at 900 and 1000 rpm and duty cycle opened lower than 60%, the output power transformation efficiency of inductor type boost converter was better than non-inductor type. When duty cycle opened larger than 60%, the output power transformation efficiency of the inductor type and non-inductor type boost converter are the same. When the rotor speed was at 1100 and 1200 rpm, the output power transformation efficiency of the inductor type and non-inductor type boost converter was the same.
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Siang-FuHong and 洪祥富. "Single-Stage Single-Switch High-Power-Factor Boost-Forward Converter with FM and PWM Composite Control." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/38244766847659705426.
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Rahman, M. M. Azizur. "Single stage soft-switched high-frequency transformer isolated AC-to-DC bridge converter and extension to multiphase converter." Thesis, 2001. https://dspace.library.uvic.ca//handle/1828/10217.
Full textAbstract:
This thesis presents the operation, analysis, simulation and experimental results of a
single-phase single-stage soft-switched high frequency (HF) transformer isolated ac-to-dc
bridge converter with low total harmonic distortion (THD) and its extension to ac-to-dc
multiphase converter. A single-phase single-stage soft-switched ac-to-dc bridge converter
cell has been proposed based on a new gating scheme. Due to the discontinuous current
mode (DCM) operation of the boost inductor, natural power factor correction and low
THD are ensured. The single-stage ac-to-dc multiphase converter is realized based on this
bridge converter cell to reduce HF harmonic components in the line current.
The steady-state operation of the single-stage bridge converter is explained for all
operating modes. Intervals of operation in these modes are identified and analyzed. The
steady-state solutions are presented. Based on these solutions, design curves are obtained.
Design example of a 1.7 kW converter is presented to illustrate the design procedure.
Operational characteristics are obtained for different line and load conditions. PSPICE
simulation results for the designed converter are presented. An experimental prototype is
built to verify the operation and performance of the converter. All four switches in the
fixed frequency bridge converter undergo soft switching (common switch requires an
auxiliary circuit) for a wide line and load range.
A single-stage HF transformer isolated ac-to-dc multiphase converter is proposed. The
analyses of the single-stage bridge converter cell are extended to the multiphase
converter. It is shown that N = 3 is near the optimum number of cells to reduce the input
current HF harmonic components. A design example of a 166 to 260 V (rms) input, 420
V output, 5 kW converter switching at 50 kHz is presented. PSPICE simulation results
are obtained for the designed converter to study its performance for varying load and line
conditions. A 3-cell 1.5 kW experimental prototype is built and experimental results are
obtained. All the results show that HF harmonics in the line current are reduced and
output voltage ripple frequency is increased. Each cell handles equal power and all
bridge-switches are soft switched. As a result, uniform thermal distribution is obtained.
Small-signal analysis of the single-stage ac-to-dc bridge converter cell is presented for
all operating modes using state-space averaging technique. Based on this analysis, small
signal transfer functions are obtained. Frequency response of the transfer functions are
plotted using MATLAB program and verified by PSPICE simulation results. A closed
loop control system is designed and frequency response of the overall loop gain is
presented. Large-signal transient behavior of the converter cell is studied with open loop
using PSPICE simulation program for step change in line and load conditions. The
simulation results show that the closed loop system is required to improve the converter
performance during step increase in line voltage.Graduate
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Yu-YaoChang and 張譽耀. "Implementation of a Single-Stage Buck-Boost-Forward Converter with Power Factor Correction." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/46803120977772488055.
Full textAbstract:
碩士國立成功大學
電機工程學系
102
Generally, an AC-DC power converter is composed of a power factor correction stage and a DC-DC converter stage. It can achieve high input power factor with input current harmonic meeting the standards. However, it increases the circuit design complexity and component number. A single-stage buck-boost-forward converter with power factor correction is presented. The front stage is a buck-boost type power factor correction to have high input power factor. With configuration of buck-boost type, the voltage stress on the storage capacitor between two stages can be reduced. The second stage is a forward converter to regulate output voltage, and the power density can be increased without the third winding of transformer. By using fuzzy control, the performance of the converter can be enhanced. The converter operates in discontinuous conduction mode can achieve zero current switching on diodes to alleviate the reverse recovery problem. The operation principles, steady-state analysis, design guidelines of the converter are presented in the thesis. In order to verify the effectiveness of the converter, a 100 W prototype with 110 Vrms line input and output voltage of DC 48 V has been implemented. The simulation and experimental results verify the theory and performance of the single-stage converter.
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Jen-HaoWang and 王任浩. "A New High-Efficiency Single- Stage AC/DC Converter with Power Factor Correction." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/91398282924183916256.
Full textAbstract:
碩士國立成功大學
電機工程學系
102
The thesis proposes a new high-efficiency, single-stage power factor correction (PFC) AC/DC converter by integrating a buck-boost power factor corrector with a flyback DC/DC converter. By replacing the inductor of PFC semi-stage with a transformer, the proposed converter not only achieves PFC, but low DC-bus voltage by providing a direct power transfer (DPT) path from the input side to output load directly. On the other hand, an energy-recycling path is designed to recycle the energy and suppress the voltage spike caused by the leakage inductance on the power switch to achieve electric isolation and to avoid the damage on power switch, as turned off in the flyback DC/DC converter. The operation principles, steady-state analysis, design guidelines of the proposed converter are presented in the thesis. To verify the effectiveness of the proposed converter, a 100 W prototype circuit with 85 Vrms to 265 Vrms line inputs and output voltage of DC 48 V has been implemented. The experimental results show that the voltage spike on the power switch can be suppressed effectively and the reverse recovery current from diodes can also be alleviated. Moreover, close-to-unity PF and maximum DC-bus voltage of well below 150 V can be obtained with the maximum circuit efficiency of 94 %.
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Yen, Jung-hung, and 顏榮宏. "A Study on Implementing a High-Power Single-Stage Converter for LED Lighting." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/59570970881474298222.
Full textAbstract:
碩士世新大學
資訊管理學研究所(含碩專班)
99
With the popularity of environmental awareness, all the research subjects focus on energy saving and environmental protection material. The light-emitting diode (LED) Lighting applications is currently in the market with the explosive development. Because of my work in the power supply circuit design field, I realize the LED lighting contribution to the environment. However, most of the existing research on the LED lighting power supply circuit focus on the small power application, i.e. under 25 W output. Because the power is small, the energy saved is limited, which inspires me to do the research on the high-power LED lighting power supply. In fact, the architecture of the LED Lighting power supply is based on the concept of Power Factor Correction (PFC) circuit. The Input current is in phase with the input voltage following the equations and simple circuit block diagram depicted in this thesis, the Power Factor value could be expected and achieved properly. It also depicts the detail operating principle, algorithms and experimental results. The experimental result is done based on the specification of lighting in real application. The PF value is up to 0.98, which has met the requirement of“ENERGY STAR” about Solid State Lighting in the commercial application (Power Factor > 0.9).
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Chou, Kuan-Fu, and 周冠甫. "Design and Implementation of A Single-Stage Asymmetrical Half-Bridge LLC Resonant Converter." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/18877956350462035523.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
103
This thesis presents a single-stage asymmetrical half-bridge LLC resonant converter, which consists of a boost-type power factor corrector (PFC) and an asymmetric half-bridge LLC resonant converter. The PFC stage adopts the voltage-follower control operating under discontinuous conduction mode. It helps to reduce the volume of the boost inductor. The current control loop is not required to reduce the circuit design complexity. By utilizing dual control function to adjust the duty cycle and the switching frequency, the proposed converter features wide range of input voltage,low output ripple,zero-voltage switching (ZVS),and zero-current switching (ZCS). This advantages are in favor of the design for high power density. The operating principle of the proposed converter has been analyzed, described and discussed in detail. The simulation using, Mathcad and SIMPLIS, were used for circuit design. The experimental results with the wide input range 85 Vac~264 Vac and an output of 19 V/120 W reveal a maximum efficiency of 90% and a maximum power factor of 0.99
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WU, PIN-SHENG, and 吳秉陞. "Design and Implementation of a Single-Stage Asymmetrical Half-Bridge Forward Resonant Converter." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/22130744581003149271.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
104
This thesis presents a single-stage asymmetrical half-bridge forward resonant converter, which consists of a active power factor corrector and an asymmetric half-bridge forward resonant converter. The PFC stage adopts the voltage-follower control operating under discontinuous conduction mode. The current control loop is not required to reduce the circuit design complexity. The control strategy is achieved for both main switch of the PFC stage and main switch of the forward stage by controlling one PWM signal, the proposed control method is varied duty cycle to operate in discontinuous conduction mode and variable frequency to regulate the output voltage. The power MOSFETs are adopted instead of Schotky diodes for the secondary rectification. The efficiency of the studied DC/DC converter with low-voltage high-current output can be increased. The proposed converter features wide range of input voltage, low output ripple, zero-voltage switching, and zero-current switching. The experimental results from the implemented prototype converter with the wide input range 85 ~ 264 Vac and an output of 19 V/120 W reveal a maximum efficiency of 89 % and a maximum power factor of 0.98 for the full load condition. By creating a loss analysis and proposed future research directions.
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LIN, YONG-HAO, and 林詠皓. "Study and Implementation of Single-Stage Interleaved Series Resonant Converter with Dual Transformers." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/41882926160216171383.
Full textAbstract:
碩士國立臺灣科技大學
電子工程系
104
This thesis presents a single-stage interleaved series resonant converter with dual transformers, which consists of two boost-type power factor corrector (PFC) and two series resonant converter. The PFC stage adopts the voltage-follower control operating under discontinuous conduction mode. It helps to reduce the volume of the boost inductor. The current control loop is not required to reduce the circuit design omplexity. The advantages of the proposed converter are that the two transformers can share the output current to reduce the copper losses and the output diode conduction losses. By utilizing two transformers, the presented converter can achieve high efficiency and high power density. The operating principle of the proposed converter has been analyzed, described and discussed in detail. The simulation using, Mathcad and SIMPLIS, were used for circuit design. The experimental results with the wide input range 180 Vac~240 Vac and an output of 200 V/200 W reveal a maximum efficiency of 89% and a maximum power factor of 0.99.
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Li, Chia-Hao, and 李佳豪. "A Single-Stage Asymmetrical Half-Bridge Power Factor Correction Converter with Coupled Inductors." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/vn8n69.
Full textAbstract:
碩士國立臺灣大學
電機工程學研究所
105
A single-stage asymmetrical half-bridge (AHB) power factor correction (PFC) converter with coupled inductors is proposed in this thesis. The proposed converter is developed from the combination of an AHB converter and a set of coupled inductors along with a blocking diode. By applying the set of coupled inductors and the blocking diode, the proposed converter can achieve single-stage AC-DC conversion with the buck-boost type PFC. Hence, the proposed converter can provide near unity power factor (PF) and low total harmonic distortion (THD) under the universal input condition without using any extra power switch and control circuit. In addition, the proposed converter can achieve zero-voltage switching (ZVS) operation for both of the power switches under the universal input condition to reduce switching loss. As a result, the proposed converter can improve the overall conversion efficiency and power density of the AC-DC converter. Therefore, the proposed converter features the advantages of near unity PF, low THD, little component counts, simple control strategy, and high circuit efficiency under the universal input condition. Computer simulation and hardware experimental results of a 100W prototype circuit are presented to verify the effectiveness of the proposed single-stage AHB PFC converter with coupled inductors.
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Yu, Da-San, and 尤德生. "Design and Implementation of Single-stage Fly-back Converter with Power Factor Correction." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/7n3u3x.
Full textAbstract:
碩士國立臺北科技大學
電力電子產業研發碩士專班
95
The objective of this paper is to design and implement a single-stage fly-back converter with power factor correction. The input voltage is 110 V/AC and output voltage is 12 V/DC. The basic principle of the single-stage fly-back converter is analyzed, and then the design and implementation of this converter are presented. For the implementation, the control IC of NCP1651 G is used as controller. Experimental results show that the power factor is higher than 0.85 and the efficiency is greater than 80%. These results fully confirm the design and implementation.
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WU, YAN-YONG, and 吳彥勇. "Development of a power converter for 3-power-ports with single-stage design." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/56f3uh.
Full textAbstract:
碩士國立虎尾科技大學
電機工程系碩士班
107
In this thesis, a single-stage isolated type power converter with three power ports is proposed the energy conversion among renewable energy port, energy storage port and dc Grid port, thus replacing traditional multistage renewable energy storage converter with a single-stage 3-port one. The power converter integrates an interleaved synchronous rectifying boost converter and bidirectional full-bridge circuit into a single-stage topology. Hence, the proposed converter will possess features of the interleaved synchronous rectifying boost converter and bidirectional full-bridge converters with bidirectional energy propagation capability and will possess the features of:(1) merging the interleaved synchronous rectifying boost converter and dual active bridge circuit into a single-stage topology with merely 4 power switches, which can regulate the renewable energy port and energy storage battery port to meet the power demand of load at the dc Grid port and effectively reduce the amount of component and cost; (2) interleaved synchronous rectifying boost converter with two inductors working in interleaved pattern, thus facilitating converter to experience greater voltage and current stresses and produce lower the current ripple. More, the energy of renewable energy port can be directly converted to energy storage battery port or to power grid dc Grid port via dual active bridge circuit; (3) the bidirectional full-bridge topology poetesses bidirectional and electrical isolation properties, thus promoting the electricity security and increasing the power capability as well as voltage rating of converter; (4) the bidirectional feature of converter enables energy the storage/release equipment to manage energy flow via DC Grid regardless of the availability of renewable power source, thus possessing the UPS capability. With the integration of two circuit structures, the proposed topology furnishes system with 3 power ports to connect renewable energy port, energy storage batteries port and dc Grid port using TMS320F28 series digital signal processor to enumerate and centrally control the PWM modules provides duty-cycle plus phase-shift control to complete 1kW power converter, the each mode conversion efficiency can reach 94%, thus deal with the power supply stability by delivering the energy from renewable energy source to power grid dc Grid directly along with the regulation of the energy storage unit.