Dissertations / Theses: 'PWM Converter'

1

Hu, Jian. "Deadbeat controlled PWM converter." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0032/MQ64227.pdf.

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Hu, Jian 1971. "Deadbeat contolled PWM converter." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=30251.

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The thesis has evaluated the suitability of Digital Deadbeat Control of the Sinusoidal Pulse Width Modulation-Voltage Source Converter (SPWM-VSC) for electric power utility applications.
The Digital Deadbeat Controlled SPWM-VSC operates as a current controller where short circuit faults are not destructive. In addition, it eliminates the L-R mode at the ac terminals of the SPWM-VSC. The thesis considers methods to immunize the control from system and parameter uncertainties. A novel closed-loop Digital Deadbeat Control has been proposed. A Phase Lock Loop (PLL) suitable for this application is developed.
Together with the PLL, the Digital Deadbeat Controlled SPWM-VSC has been shown to be capable of (1) independent control of current Id and Iq, (2) near sinusoidal current waveforms, (3) broad operation frequency range.
Digital simulation is used in the thesis to prove the performance of the Digital Deadbeat Controlled SPWM-VSC.

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3

Stihi, Omar. "Single phase controlled current PWM converter." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=63844.

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4

Cazzell, Gregory A. "Output Impedance in PWM Buck Converter." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1247006982.

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5

Kulkarni, Ashok. "Characteristics of a controlled current PWM converter." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=66006.

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6

Nishimoto, Masahiro. "Analytical study of a controlled current PWM converter." Thesis, McGill University, 1986. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=65432.

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7

Ye, Zhihong. "Modeling and Control of Parallel Three-Phase PWM Converters." Diss., Virginia Tech, 2000. http://hdl.handle.net/10919/29476.

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This dissertation studies modeling and control issues of parallel three-phase pulse-width modulated (PWM) converters. The converters include three-phase boost rectifiers, voltage source inverters, buck rectifiers and current source inverters. The averaging of the parallel converters is performed based on a generic functional switching unit, which is called a phase leg in boost rectifiers and voltage source inverters, and a rail arm in buck rectifiers and current source inverters. Based on phase-leg and rail-arm averaging, the developed models are not only equivalent to the conventional three-phase converter models that are based on phase-to-phase averaging, but they also preserve common-mode information, which is critical in the analysis of the parallel converters. The models reveal such parallel dynamics as reactive power circulation and small-signal interaction. A unique feature of the parallel three-phase converters is a zero-sequence circulating current. This work proposes a novel zero-sequence control concept that uses variable zero-vectors in the space-vector modulation (SVM) of the converters. The control can be implemented within an individual converter and is independent from the other control loops for the converter. Therefore, it greatly facilitates the design and expansion of a parallel system. Proper operation of the parallel converters requires an explicit load-sharing mechanism. In order to have a modular design, a droop method is recommended. Traditionally, however, a droop method has to compromise between voltage regulation and load sharing. After parametric analysis, a novel droop method using a gain-scheduling technique is proposed. The numeric analysis shows that the proposed droop method can achieve both good voltage regulation and good load sharing. An interleaving technique is often used in parallel converter systems in order to reduce current ripples. Because of its symmetrical circuit structure, the parallel three-phase converter system can reduce both differential-mode and common-mode noise with a center-aligned symmetrical SVM. Based on the concept that a symmetrical circuit can reduce common-mode dv/dt noise, a conventional three-phase, four-leg inverter is modified so that its fourth leg is symmetrical to the other three legs. The common-mode dv/dt noise can be practically eliminated with a new modulation strategy. Meanwhile, with a modified control design, the new four-leg inverter still can handle low-frequency common-mode components that occur due to unbalanced and nonlinear load.
Ph. D.

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8

Van, der Merwe Wim. "PWM converter for a highly non-linear plasma load." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/3025.

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Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2005.
This thesis discuss an investigation into the applicability of modern high frequency power conversion technology in the plasma mineral processing industry. The physics governing the plasma in a processing environment are analysed to provide a clear understanding of this plasma as electrical load. This was done to create an electrical model for the plasma as load and gain understanding into the electrical supply requirements. Modern high frequency power conversion technology is contrasted with thyristor controlled line frequency technologies to provide a suitable starting point for the study. A 3 kW soft switched converter is proposed for application with a plasma load. This converter is designed and verified. The small-signal signature of the proposed converter under peak current mode control is investigated and a new model is proposed to describe this control configuration.

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9

Shen, Jian. "GTO Pulsed Width Modulated (PWM) converter for railway traction applications." Thesis, University of Salford, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.308484.

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10

Dalvi, Mahesh. "Computer controlled generation of PWM waveform using harmonic distortion minimization scheme." Ohio : Ohio University, 1997. http://www.ohiolink.edu/etd/view.cgi?ohiou1177442328.

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11

Lee, Dong-Myung. "A Voltage Sag Supporter Utilizing A PWM-Switched Autotransformer." Diss., Georgia Institute of Technology, 2004. http://hdl.handle.net/1853/5215.

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This research suggests a novel voltage control scheme that can compensate for voltage sag and swell conditions in three-phase power systems. Faults occurring in power distribution systems or facilities in plants cause the voltage sag or swell. For sensitive loads, even voltage sags of short duration can cause serious problems in the entire system. In order to mitigate power interruptions, this research proposes a scheme called Voltage Sag Supporter utilizing a PWM (Pulse Width Modulation)-Switched Autotransformer. The proposed scheme is able to quickly recognize the voltage sag or swell condition, and it can correct the voltage by either boosting the input voltage during voltage sag events or reducing the input voltage during voltage swell events. Among existing methods, the scheme based on the inverter system such as dynamic voltage restorers (DVR) require an inverter, a rectifier, and a step-up down transformer, which makes the system expensive. AC converters can be used for the purpose of the research. However, they consist of two solid-state switches per one phase and include energy storage devices such as reactors and capacitors. The switching device for the high voltage application is relatively expensive so that this research suggests a scheme utilizing only one switch for the output voltage control, which makes the system more stable and cost effective. The proposed scheme can be applied at any voltage and provides cost and size advantages over existing methods due to the reduced number of switching components and no need of energy storage devices. Simulations and experiments have been carried out to verify the validity of the proposed scheme, and prototype experiments are being done to confirm the control scheme.

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12

Wan, Hongmei. "High Efficiency DC-DC Converter for EV Battery Charger Using Hybrid Resonant and PWM Technique." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/32343.

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The battery charger plays an important role in the development of electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs).This thesis focuses on the DC-DC converter for high voltage battery charger and is divided into four chapters. The background related to EV battery charger is introduced, and the topologies of isolated DC-DC converter possibly applied in battery charge are sketched in Chapter 1. Since the EV battery charger is high voltage high power, the phase-shifted full bridge and LLC converters, which are popularly used in high power applications, are discussed in detail in Chapter 2. They are generally considered as high efficiency, high power density and high reliability, but their prominent features are also limited in certain range of operation. To make full use of the advantages and to avoid the limitation of the phase-shifted full bridge and LLC converters, a novel hybrid resonant and PWM converter combining resonant LLC half-bridge and phase shifted full-bridge topology is proposed and is described in Chapter 3. The converter achieves high efficiency and true soft switching for the entire operation range, which is very important for high voltage EV battery charger application. A 3.4 kW hardware prototype has been designed, implemented and tested to verify that the proposed hybrid converter truly avoids the disadvantages of LLC and phase-shifted full bridge converters while maintaining their advantages. In this proposed hybrid converter, the utilization efficiency of the auxiliary transformer is not that ideal. When the duty cycle is large, LLC converter charges one of the capacitors but the energy stored in the capacitor has no chance to be transferred to the output, resulting in the low utilization efficiency of the auxiliary transformer. To utilize the auxiliary transformer fully while keeping all the prominent features of the previous hybrid converter in Chapter 3, an improved hybrid resonant and PWM converter is proposed in Chapter 4. The idea has been verified with simulations. The last chapter is the conclusion which summaries the key features and findings of the two proposed hybrid converters.
Master of Science

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13

Gitau, Michael N. "Optimal PWM switching strategy for single-phase AC-DC converters." Thesis, Loughborough University, 1994. https://dspace.lboro.ac.uk/2134/7205.

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The thesis describes an optimal selective harmonic elimination strategy suitable for singlephase AC-DC converter-fed traction drives. The objective is to eliminate low-order supply current harmonics, including those injected into the supply due to load-side current ripple. Other advantages that the switching strategy has to offer over phase-control include improved supply power factor, reduced VA consumption for a given demand speed and load, reduced torque and speed ripple and smaller armature circuit smoothing inductance. The effect of field current boost on the dynamic response of the drive is also described. It is shown that field boost helps to reduce the speed rise-time by increasing the electromagnetic torque available during acceleration periods. Closed-loop control of a 4-quadrant DC drive is described and a comparison made between the performance of PID-control and pseudo-derivative feedback control. It is shown that pseudo-derivative feedback control has several advantages to offer, amongst which are ease of tuning of the controller gains and a superior performance following load torque disturbances. A laboratory size drive system was designed and built, and used to validate simulation predictions for both the switching strategy and pseudo-derivative feedback control. A microcontroller based hardware implementation of both the switching strategy and a digital pseudo-derivative feedback controller was adopted, with the switching strategy being implemented using an off-line approach of precalculating the switching angles and storing these in look-up tables. The armature voltage controller comprises a dual-converter employing IGBTs as switching devices. The use of IGBTs allows higher switching frequencies at significant power levels than would be possible if GTOs were used. It also simplifies the gate drive circuit design and minimises the need to use snubber circuits.

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14

Fraser, Malcolm E. "Power factor-corrected transformerless three-phase PWM converter for UPS applications." Thesis, Loughborough University, 1996. https://dspace.lboro.ac.uk/2134/33002.

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This thesis describes the research of a new transformerless three phase PWM converter for uninterruptible power supplies (UPS) applications. The removal of the bulky three phase transformer in larger power UPS can provide a significant saving in weight and cost of the overall system. The converter consists of a new four-wire rectifier coupled with a four-wire inverter via a dc bus. The supply and load neutral may be connected together without any neutral current flowing into the utility regardless of the load on the inverter. This allows the load to be at the same potential as the utility. The rectifier, inverter and complete UPS and control system are described in detail and simulation results are used extensively to back up the theory. An experimental prototype of the four-wire rectifier provides further confirmation of the principles. A further proposal to digitize the system is given. This would reduce the size of the required control circuit and simplify the hardware requirements.

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15

Kathi, Lokesh. "Steady-State Analysis of PWM Z-Bridge Source DC-DC Converter." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1453223069.

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16

Dasari, Anuroop Reddy. "The steady-state analysis of the non-isolated and isolated type SEPIC PWM DC-DC converters for CCM." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1599672947653384.

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17

Vlatkovic, Vlatko. "Small-signal analysis of the phase-shifted zero-voltage switched PWM converter." Thesis, This resource online, 1991. http://scholar.lib.vt.edu/theses/available/etd-12172008-063107/.

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18

Xiao, Yuan. "PWM GTO AC to DC current source converter for high power applications." Thesis, Teesside University, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.411190.

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19

Nisar, Kashif. "DC to DC converter for smart dust." Thesis, Linköpings universitet, Institutionen för systemteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-77247.

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This work describes the implementation of DC to DC converter for Smart Dust in 65 nm CMOS technology. The purpose of a DC to DC converter is to convert a battery voltage of 1 Vto a lower voltage of 0.5 V used by the processor. The topology used in this DC to DC converteris of Buck type which converts a higher voltage to lower voltage with the advantage of givinghigh efficiency about 75%. The system uses PWM (Pulse width modulation) technique. It usesnon-overlapping clock generation technique for reducing the power consumption. The systemprovides up to 5 mA load current and has power consumption of 2.5 mW.

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20

Manh, Vir Varinder. "An Integrated High Efficiency DC-DC Converter in 65 nm CMOS." Thesis, Linköpings universitet, Elektroniksystem, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-61237.

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This thesis work describes the implementation perspective of an integrated high efficiency DC-DC converter implemented in 65 nm CMOS. The implemented system employs the Buck converter topology to down-convert the input battery voltages. This converter offers its use as a power management unit in portable battery operated devices. This thesis work includes the description of a basic Buck converter along with the various key equations involved which describe the Buck operation as well as are used to deduce the requirements for the various internal building blocks of the system. A detailed description of the operation as well as the design of each of the building blocks is included. The implemented system can convert the input battery voltage in the range of 2.3 V to 3.6 V into an output supply voltage of 1.6 V. The system uses dual-mode feedback control to maintain the output voltage at 1.6 V. For the low load currents the PFM feedback control is used and for the higher load currents the PWM feedback control is used. This converter can supply load currents from 0 to 300 mA with efficiency above 85%. The static line regulation of the system is < 0.1% and the load regulation of the system is < 0.3%. A digital soft-start circuit is implemented in this system. The system also includes the capability to trim the output voltage in ~14 mV steps depending on the 4-bit input digital code.

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21

Rashid, Tariq. "Perturbation model based analysis of a three phase PWM ac-dc power converter." Thesis, University of Bristol, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.336819.

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22

Salvatierra, Thomas R. "PWM Buck Converter as a Dynamic Power Supply for EnvelopeTracking and Amplitude Modulation." Wright State University / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=wright1453826990.

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23

Lee, John C. "Magamp post-regulator applied to a quasi-resonant converter and magamp operation under extreme load condition in a PWM converter." Thesis, This resource online, 1988. http://scholar.lib.vt.edu/theses/available/etd-11072008-063123/.

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24

Al-Qrimli, Fadhil Abbas Mehdi. "An energy conversion scheme using a permanent magnet generator and a PWM, GTO converter." Thesis, University of Liverpool, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.304736.

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25

Dong, Dong. "Modeling and Control Design of a Bidirectional PWM Converter for Single-phase Energy Systems." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/33163.

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This thesis proposes a complete modeling and control design methodology for a multifunctional single-phase bidirectional PWM converter in renewable energy systems. There is a generic current loop for different modes of operation to ease the transition between different modes, including stand-alone inverter mode, grid-tied inverter mode, grid-tied rectifier mode and grid-tied charger/discharger mode. Under stand-alone mode operation, ac voltage regulation is of importance because of the sensitive loads. In this thesis, different multi-loop-based control schemes are investigated and compared, especially between the load current feedback control, PR control and capacitor current loop control. It shows that PR controller reduces the steady-state error, while load current feedback controller improves the transient response. However, the load current feedback controller and capacitor current loop controller presents unstable outputs under some filter load condition. Single-phase d-q frame control is also studied. In order to ease the implementation effort, an unbalanced d-q frame control is proposed to achieve zero steady-state error voltage regulation without generating Î²-axis component. Based on the same principle, a d-q frame-based single-phase PLL is also proposed to achieve the fast dynamic response with the zero steady-state error phase tracking.

The entire control system is verified on a modified 7 kW single-phase PWM converter prototype with a simple DSP-based digital implementation. The load step response test is presented under different modes of operation. The controllers for stand-alone mode are also done under no load, 1 kW resistive load, 1kVar capacitive load, and non-linear load conditions verifying that the single-phase d-q achieves 70% steady-state error improvement if taking the normal PID controller as the baseline design. In the end, the proposed PLL is compared with the standard PLL by experiments showing that the steady-state error can be reduced by 80%.
Master of Science

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26

Kolakowski, Terry. "Fuzzy Logic Control of a Switched-Inductor PWM DC-DC Buck Converter in CCM." Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1251310342.

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27

Galigekere, Veda Prakash Nagabhushana. "Stead-State and Small-Signal Modeling of Power-Stage of PWM Z-Source Converter." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1333994573.

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28

Shoubaki, Ehab. "UNIFIED LARGE AND SMALL SIGNAL STATE-SPACE BASED MODELING AND SYMBOLIC SIMULATION FOR PWM CONVERTERS." Doctoral diss., University of Central Florida, 2009. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3960.

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In this Dissertation, which concentrates on discrete modeling for control purposes of DC/DC converters and simulation through symbolic techniques. A Unified Discrete State-Space Model for power converters in CCM is presented. Two main approaches to arriving at the discrete model are used. The first approach involves an impulse function approximation of the duty cycle modulation of the converter switches, and this approach results in a small signal discrete model. The Second approach is direct and does not involve any approximation of the modulation, this approach yields both a large signal nonlinear discrete model and a linear small signal model. Harmonic analysis of the converter's states at steady-state is done for steady-state waveform acquisition, which increases the accuracy of the model especially for finding the control to inductor current frequency response. Also the harmonic Analysis technique is used to both obtain the response of the converter to a load transient and to finding the optimal duty cycle response that minimizes the disturbance. Finally the Discrete model is verified for the Half-Bridge DC/DC topology for its three main control schemes (Asymmetric, Symmetric, DCS). A GUI platform in MATLAB is presented as a wrapper that utilizes the models and analysis presented in this thesis. Symbolic simulation techniques are developed in general manner for linear piecewise circuits and then through State-Space formalism specialized for DC/DC converters. A general symbolic solver programmed in JAVA that implements said techniques is presented.
Ph.D.
School of Electrical Engineering and Computer Science
Engineering and Computer Science
Electrical Engineering PhD

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29

Gall, Jonathan Henrik. "Zero-Voltage-Switching PWM Full-Bridge Converter for Onboard Charging of Battery of Electric Vehicles." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2019.

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This thesis gives a description of working principles of a Phase-Shifted Full-Bride PWM ZVS converter using a Full-Wave rectifying output as well as a Double Current Rectifier. After a description of each topology and some differences between the two topologies, a hybrid solution is presented. The hybrid configuration is a combined FW and DCR, in an interleaved connection. By the opening and closing of a switch that is located between the two output stages, either a DCR-DCR or DCR-FW rectifying output stage is used for the converter. This allows for dynamic turns ratio of the step-up transformer of the converter, as well as reduced primary and secondary side currents. The voltage for when to switch between the two output configurations is derived analytically. Simulations carried out in LTSpice to verify the analytical results and the hypothesis of reduced currents and losses are presented in the end.

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Zhao, Xiaonan. "A High-efficiency Isolated Hybrid Series Resonant Microconverter for Photovoltaic Applications." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/78312.

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Solar energy as one type of the renewable energy becomes more and more popular which has led to increase the photovoltaic (PV) installations recently. One of the PV installations is the power conditioning system which is to convert the maximum available power output of the PV modules to the utility grid. Single-phase microinverters are commonly used to integrate the power to utility grid in modular power conditioning system. In the two-stage microinverter, each PV module is connected with a power converter which can transfer higher output power due to the tracking maximum power point (MPP) capability. However, it also has the disadvantages of lower power conversion efficiency due to the increased number of power electronics converters. The primary objective of this thesis is to develop a high-efficiency microconverter to increase the output power capability of the modular power conditioning systems. A topology with hybrid modes of operation are proposed to achieve wide-input regulation while achieving high efficiency. Two operating modes are introduced in details. Under high-input conditions, the converter acts like a buck converter, whereas the converter behaves as a boost converter under low-input conditions. The converter operates as the series resonant converter with normal-input voltage to achieve the highest efficiency. With this topology, the converter can achieve zero-voltage switching (ZVS) and/or zero-current switching (ZCS) of the primary side MOSFETs, ZCS and/or ZVS of the secondary side MOSFETs and ZCS of output diodes under all operational conditions. The experimental results based on a 300 W prototype are given with 98.1% of peak power stage efficiency and 97.6% of weighted California Energy Commission (CEC) efficiency including all auxiliary and control power under the normal-input voltage condition.
Master of Science

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31

Urciuoli, Damian. "Switching Stage Design and Implementation for an Efficient Three-Phase 5kW PWM DC-DC Converter." Thesis, Virginia Tech, 2003. http://hdl.handle.net/10919/34378.

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With the development of fuel cell based power systems, the need for more advanced DC-DC power converters has become apparent. In such applications DC-DC converters provide an important link between low voltage fuel cell sources and inverter buses operating at significantly higher voltages. Advancements in converter efficiency, cost reduction, and size reduction are the most necessary. These challenges are formidable, even when considering the improvements made to conventional DC-DC topologies. However, it can be possible to achieve these criteria through the implementation of more advanced topologies. A recently developed efficient three-phase DC-DC topology offers benefits over standard designs. Passive component sizes and output ripple voltage were reduced as a result of an effective boost in switching frequency. Converter output voltage was reached more easily due to an increased transformer voltage boost ratio in addition to the turns ratio. For cost reduction, the converter was designed and built with discrete components instead of more expensive integrated modules. This thesis presents an overview of the three-phase converter, with a detailed focus on the design, implementation, and performance of the switching stage. The functionality of the three-phase topology is covered along with the selection of converter components. Simulation results are shown for both ideal and real converter models. Considerations for the switching device package with respect to circuit board and heat sinking configurations are discussed in support of the selection of an insulated metal substrate (IMS) circuit board. An effective circuit layout designed to minimize parasitic trace inductances as well as provide favorable component positioning is presented. Experimental converter test results are shown and the causes of undesired effects are identified. Switching stage modifications and their results are discussed along with the benefits of proposed future design enhancements.
Master of Science

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32

Franklin, Calenia L. "Design and Simulation of Boost DC - DC Pulse Width Modulator (PWM) Feed-Forward Control Converter." Wright State University / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=wright1594392395108745.

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33

Lee, Julie JoAnn. "Steady-State and Small-Signal Modeling of a PWM DC-DC Switched-Inductor Buck-Boost Converter in CCM." Wright State University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=wright1340804411.

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34

Zackiewicz, Curt Stephen. "DC-DC Power Converter Design for a Portable Affordable Welder System (PAWS)." Wright State University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=wright1300807818.

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Lee, Julie JoAnn. "Analysis of a Small-Signal Model of a PWM DC-DC Buck-Boost Converter in CCM." Wright State University / OhioLINK, 2007. http://rave.ohiolink.edu/etdc/view?acc_num=wright1187882268.

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36

Shoubaki, Ehab Hamed. "UNIFIED LARGE AND SMALL SIGNAL DISCRETE-SPACE MODELING FOR PWM CONVERTERS IN CCM." Master's thesis, University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3961.

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In this Thesis a Unified Discrete State-Space Model for power converters in CCM is presented. Two main approaches to arriving at the discrete model are used. The first approach involves an impulse function approximation of the duty cycle modulations of the converter switches , and this approach results in a small signal discrete model. The Second approach is direct and does not involve any approximation of the modulations , this approach yields both a large signal nonlinear discrete model and a linear small signal model. Harmonic analysis of the converter states at steady-state is done for steady-state waveform acquisition , which increases the accuracy of the model especially for finding the control to inductor current frequency response. Finally the Discrete model is verified for the Half-Bridge DC/DC topology for its three main control schemes (Asymmetric , Symmetric , DCS). A GUI platform in MATLAB is presented as a wrapper that utilizes the models and analysis presented in this thesis.
M.S.E.E.
Department of Electrical and Computer Engineering
Engineering and Computer Science
Electrical Engineering

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37

Colmenares, Juan. "ANALYSIS, IMPLEMENTATION AND EXPERIMENTAL EVALUATION OF A PHASE SHIFTED PWM CONTROL SYSTEM FOR A MODULAR MULTILEVEL CONVERTER." Thesis, KTH, Elektrisk energiomvandling, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-53658.

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Nowadays, it is problematic to connect only one power semiconductor switch directly to the grid due to the high voltage range. In order to solve this difficulty, a new type of power converter has been introduced as a solution in high power applications. Multilevel Converters use high speed switching components, avoiding the problem of linking them directly to the grid by connecting single devices among multiple DC levels. Differents Multilevel topologies have been developed in the last few years. Multilevel Converters are more complex to modulate than the two level traditional converters because of the number of switching alternatives that are available. The latest and most promising such topology for high power applications is the Modular Multilevel Converter (M2C). Several control and modulation methods have been suggested for this topology. The aim of this master thesis project is to deeply investigate and evaluate one of them, based on a carrier phase-shifted Pulse Width Modulation (PWM) techniques. Four different control topologies using phase shift PWM techniques on M2C are studied and explored in this work. These topologies include the following loops of control: Averaging Control based on the currents inside the converter, Individual Balancing Control based on the output current and capacitors voltages, and Arm Balancing Control based on the voltage difference between the arms of the converter. The operation principle of an M2C is presented. This project proposes a switching frequency that meets the two required criteria: low enough to maintain cost feasibility, and high enough to reach a harmonic performance target. Additionally, this work proposes an analytic expression for the output voltage spectrum of the converter, which enables prediction of harmonic performance. Three distinct simulations were performed each one using different control topologies and switching frequencies. The first controller simulated took into account the Averaging Control topology, based on the circulating current. Within this topology both individual and arm balancing techniques are also explored. A second controller is also simulated using Averaging Control, based on the arms currents, as well as the other control loops. For the last case an Averaging Control, based on the arm currents, without the Arm Balancing is simulated. The results of each simulation are discussed and compared. Finally, these topologies are implemented and verified experimentally on a 10-KVA M2C prototype. The experiments are performed using only one phase and 11-level modulation methods. The controller efficiency is studied and verified through step response analysis.

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Fan, Bo-Wen, and 范柏文. "PWM/PFM Mixed Modulation Controller for Twin-Buck Converter." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/67943607213286577432.

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碩士
國立中山大學
電機工程學系研究所
101
In the thesis, we apply the state average method to model the time-average linear dynamic equation, which is used to design a gain scheduled linear quadratic optimal controller. Because the standard modulation method of the twin-buck converter is PFM(Pulse-Frequency Modulation) and twin-buck converter owns the soft-switching characteristic, the voltage step-down ratio, that is, control force can not be lowered less than 0.5. For expanding the range of control force of converter, we modulate the converter by means of mixed modulation of PWM/PFM. With the former odulation method, we have to calculate the discharging time of synchronous switch taken by controller to achieve zero-voltage-transition (ZVT). In the last part of this thesis, we verify the practicability of the controller and modulation method through soft simulation coded by MATLAB and hardware implementation of FPGA driven by Verilog.

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39

Tsai, Chih-Hsin, and 蔡至鑫. "Spread-Spectrum Clock Generators for PWM Converter." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/56484709613161936953.

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碩士
國立臺灣海洋大學
電機工程學系
96
In today's integrated circuit systems, there is a thriving demand for better efficiency and faster speed. Most of these devices have clock generators, digital clock circuits, and radio-frequency (RF) circuits, which are the most significant contributors of electromagnetic interference (EMI).Currents and voltages present in these circuits, such as those found in their signal traces, lead to greater EMI when operating in high frequencies. In present systems, EMI may well interfere with the operation of its source circuit as well as the equipment adjacent to it. The content of this thesis addresses the problem of EMI by presenting a design of a Spread-Spectrum Clock Generator (SSCG) for Pulse-Width Modulation (PWM) Converter Chip. 　　A popular method for SSCG is with modulation on the divider modulus or the delta-sigma modulator adopts a variable loop bandwidth to provide more accurate control on spread amounts. The spread spectrum technique used in this thesis is achieved by modulating the control voltage of the VCO. Therefore, both the hardware complexity and the consume power and the chip size are reduced. The chip can supply output spread frequencies between 500K ~ 12MHz. The measurement results show it can reduce EMI of 10~20 dB. The power consumption of this SSCG is 2.51mW, and the chip area is 0.8464 mm with 0.35-μm CMOS process.

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40

Lin, Yen-Sheng, and 林晏生. "Digitally Controlled PWM for DC-DC Converter." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/29560258537137251611.

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碩士
國立交通大學
電機學院IC設計產業專班
96
The purpose of this thesis is to study and produce a full digitally controlled PWM for DC-DC converting circuit based on FPGA.This thesis is aimed at building a mathematically effective module equal to a Digitally Controlled PWM for DC-DC Converter; therefore, to explore the circuit quality, the pulse-width modulating fashion, and the way of realizing the converter. The controlling structure is based on the PID controller as its designing model, including the designing of the proportional controller, the integral controller, and the derivative controller, to enhance low frequency gain and phase margin, and to upgrade the relative stability at close loop system circuit, in order to expedite the transient response and minimize Steady state error. Simulating platform takes the ModelSim/Simlink software to simulate system integration to examine its function correctness. At the experiment, either FPGA/CPLD or inserting style system Xilinx ISE development software and ULINX_MB_XC3S250E_PQ208_V20A has been used, by the system circuit of the Buck voltage converter, to examine the function and quality of the designed digital controller.

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41

Cheng, Wen-Chieh, and 鄭文傑. "PWM Controller ICs for DC-DC Converter." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/49547821618673899875.

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碩士
大葉大學
資訊工程學系碩士班
95
This thesis describes two complete PWM controller IC for switching power converters. One is analog PWM controller IC and another is digital PWM controller IC. Due to rapid development of CMOS technologies, more and more transistors can be fabricated on a single chip. Consumer electronic products also have been developed rapidly in these years. The power management ICs such as the highly efficient low-voltage switch-mode DC-DC converters are mandatory in these devices for maximizing the system run time. The analog-control scheme for the switching converters is developed for a long time, and it is a very mature technique. The digital-control scheme for the switching DC-DC converters also has been discussed in these years. The advantages and disadvantages between these two architectures are treated in this thesis. The key building blocks of analog PWM controller IC are two-stage operational amplifier, voltage-controlled oscillator and hysteretic comparator. The key building blocks of digital PWM controller IC are A/D converter, compensator and DPWM. These two controller ICs have been fabricated with TSMC 0.35um 2P4M 3.3V/5V Mixed Signal CMOS process through CIC. The chip size of APWM is about 0.35*0.37mm2. The chip size of A/D converter is about 0.555*0.555mm2. The chip size of DPWM is about 0.65*0.56mm2.

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42

LEE, CHIA-CHUN, and 李嘉峻. "A DC-DC BUCK CONVERTER IC WITH PWM/PFM DUAL MODE CONTROL." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/16548803252225836529.

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碩士
大同大學
電機工程學系(所)
104
A DC-DC bulk converter has been designed and simulated with TSMC 0.35 CMOS models. To improve the conversion efficiency, the converter is designed to switch between two modes, PWM mode for heavy load and PFM mode for light load. This converter with on-chip current sensor can operate from 300 kHz to 600kHz with supply voltage from 3 to 5 V suitable for battery supply applications. With a 3.7V supply, switching frequency 262.47kHz, a 10-µF off-chip capacitor and a10-µH off-chip inductor, the HSPICE simulation results show that the output ripple voltage is about 20 mV and the maximum power efficiency is 84% at load current of 400mA in PWM mode. The output ripple voltage is about 600 mV and the maximum power efficiency is 75% at load current of 80 mA in PFM mode.

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43

Liu, Chia-Szu, and 劉佳賜. "A CMOS DC-DC Buck Converter with PWM/PFM Dual-Mode Control." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/2jefwj.

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碩士
大同大學
電機工程學系(所)
107
This thesis proposes a DC-DC buck converter with TSMC 0.35μm CMOS process, using pulse width modulation (PWM) and pulse frequency modulation (PFM) dual mode switching to reduce output voltage ripple and improve conversion efficiency. This circuit is designed for products with the power supply input voltage from 3V to 5V. The output voltage is stepped down to 3V. The operating frequency of PWM is 1MHz. The HSPICE simulation results show that the output voltage ripple is less than 15mV and the optimum conversion efficiency is from 93% to 95% at 150mA load current with a 10μF external capacitor and a 10μH external inductor.

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44

Yu, Liao-Ting, and 廖庭鈺. "Analysis of Full Bridge Converter Based on Symmetric PWM and Phase-Shift PWM." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/826bwn.

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碩士
國立雲林科技大學
電機工程系
107
This thesis studies a full-bridge converter based on symmetric PWM and phase-shift PWM schemes. The PWM control schemes are implemented by using the integrated circuits UCC3895 and KIA494P. The main advantage of phase-shift PWM scheme is the soft switching operation on power MOSFET. The drawback of symmetric PWM scheme is hard switching loss on power devices. The current double rectifier topology is used on the secondary side to reduce the output current ripple. Finally, a laboratory prototype is built and experiments are provided to show the circuit performance.

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45

Huang, Jia-Ching, and 黃嘉卿. "Design of a Current-Mode High-Efficiency PWM/PSM DC-DC Buck Converter." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/b8gk63.

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碩士
國立臺灣海洋大學
電機工程學系
106
Owing to the development of technology, the applications of portable electronic devices have been broadened to a wider scope. Due to global energy depletion and people’s desire of lighter and more convenient products, the need for portable electronic devices has also increased significantly. This trend makes the effective use of power and the reduction of the size of power management module become essential research topics. To be exact, the miniaturization of power management modules and the improvement of conversion efficiency become primary consideration. 　　In this thesis, the buck converter is designed using current mode control and operates in high switching frequencies. This converter can apply different modulation mode in different loads. For example, pulse width modulation mode (PWM) is used in heavy loads, and pulse skipping modulation mode (PSM) in light loads. As for the switching losses of a converter, a Power MOSFET is divided into three groups in this structure, and the number of the power MOSFETs turned on or not is determined by the size of the detected load current. Combined with the above two methods, the design is divided into four loads ranges, and significantly reduces the switching losses and optimizes conversion efficiency. This converter chip has been implemented using TSMC 0.35μm 2P4M 5V Mixed-Signal CMOS process. The power supply ranges from 3 volts to 4.2 volts. The load current range is 30 to 500mA. The output voltage is 1.8 volts at switching frequency of 10MHz. The maximum conversion efficiency is 88.5%. The external inductor and capacitor values are reduced to 1uH and 4.7uF respectively, which is suitable for applications of portable electronic products. Keywords: Buck converter, current mode, conversion efficiency, PWM, PSM

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46

Ma, Shaohua. "Optimal PWM control of a stacked multicell converter." 2005. http://hdl.handle.net/1993/18047.

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47

Hsiao, Chia Wen, and 蕭嘉文. "Digital PWM controller for DC-DC Boost Converter." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/96469072407712879427.

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碩士
長庚大學
電機工程學系
98
In this paper , a digital pulse width modulation controller of the dc-dc switching converter designed for the integrated circuit is implemented and verified .The technology used in pulse width modulation is popularly applied in present power electronic field . This technology is used to improve the efficiency and save more energy resources in the design of the circuit. And that, the design in this digital pulse width modulation controller is based on the theory and improvement of the PI controller and the pwm controller .Comparing with the method look up table used in PID controller , the design in our circuit not only save lots of memory area but also remove the differential controller . In this cicuit, the output signal of the dc-dc boost converter go throuth the ADC673 IC become a control feedback signal. And the signal processed by the ADC 673 IC send to the encoder to become a input signal of the rear controller;The rear controller is implemented by the FPGA components. In the experiment process , the matlab/simulink software is used to simulate the result in computer. The Quartus software and FPGA components are used in final measure phase. Finally the boost converter, the ADC673 IC and the FPGA components are to combine to form one circuit , in order to demonstrate the function and performance of the designed digital controller.

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48

黃照霖. "A Study of Boost PWM Soft-Switching Converter." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/45911820671121329664.

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碩士
國立臺灣海洋大學
電機工程學系
96
Abstract This thesis presents Boost converter with a passive snubber to reduce the switching losses. The circuit topology of the converter consists of traditional Boost converter and a passive snubber, the snubber composed of a capacitor, an inductor and diodes, is able to operate with soft switching in a pulse width modulation and improve the traditional switching power converter since high switching frequency accompanied high switching losses. Finally simulation and experimental results are given to verify it’s correctly and practicability.

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49

Wang, Chen-Yi, and 王偵亦. "Efficiency Model for Power Converter with PWM Jitter." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/47051367823007617559.

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碩士
國立臺灣大學
電機工程學研究所
104
The objective of this thesis is to investigate the impact of the PWM Duty Cycle jitter (PWM Jitter) on the power converter as well as to establish its efficiency model. By adopting a strategy based on the proposed efficiency model, designers can avoid the efficiency drop caused by PWM jitter. In this thesis, the origin of PWM jitter and the efficiency of power converter are presented first. The synchronous buck DC converters are selected for illustration. Next, a methodology by using the state-space averaging method to find out the impact of the PWM jitter on the power conversion efficiency is proposed. Two efficiency models are developed, one for the constant resistance load and the other for the constant current load. Then, the efficiency drops caused by different PWM jitter’s frequency or amplitude are compared. In order to eliminate the measurement inaccuracy caused by the thermal drift, a LabVIEW-based programmable automatic measuring system is established. Finally, the computer simulations and the hardware experiments confirm the accuracy of the proposed efficiency models.

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50

Lin, Syuan-Li, and 林軒立. "Analysis of the Zero-Voltage Transition PWM Boost Converter." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/y6gnjj.

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碩士
國立臺灣海洋大學
電機工程學系
102
The purpose of this thesis is to analyze a new Zero-Voltage Transition PWM Boost Converter. The converter operates with an active snubber cell, which provides main switch to turn ON with zero-voltage transition (ZVT) and to turn OFF with zero-current transition (ZCT). Furthermore, all semiconductor devices of this converter operate with soft switching at high frequency. The structure of this converter is simple and easy to control. The operation principle and steady-state analysis of the novel boost converter are presented. Finally, the converter feature is proved by simulation.

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