Дисертації з теми "Active current"
Щоб переглянути інші типи публікацій з цієї теми, перейдіть за посиланням: Active current.
Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями
Ознайомтеся з топ-50 дисертацій для дослідження на тему "Active current".
Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.
Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.
Переглядайте дисертації для різних дисциплін та оформлюйте правильно вашу бібліографію.
1
Carpenter, Paul Andrew. "Active filter current compensation for transmission optimisation." Master's thesis, University of Cape Town, 2015. http://hdl.handle.net/11427/24291.
Повний текст джерелаАнотація:
This dissertation is based on the fact that any m-wire electrical system can be modelled as m-equivalent Thevenin voltages and impedances when viewed from any node. The dissertation describes how to calculate the optimal distribution of currents, so a specific amount of power can flow through and reach the network equivalent Thevenin voltages with minimal losses. The optimal current distribution method uses a recently patented method which calculates the optimal currents for each of the wires which are shown to be obtained from the Thevenin parameters and power flow at any instant in time at any node. Once the ideal currents are found, these can be obtained by active and passive devices to inject a specific amount of power (positive and negative) as to compensate existing currents. The focus is particularly on the proof of concept by simulations and physical experiments with work not specifically described in the patent with more emphasis on the optimisation to active compensation. It is explained and shown how this can be implemented using the Malengret and Gaunt method. This method reduces the cost in application where not all the currents need to be processed through a converter (e.g. inverter) but only the difference between the existing and desired optimal currents. A smaller shunt parallel converter can result with ideal current flow without the need for interrupting the currents as described in the present patent. The methodology is explained and demonstrated by simulation.
2
Ozkaya, Hasan. "Parallel Active Filter Design, Control, And Implementation." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608438/index.pdf.
Повний текст джерелаАнотація:
The parallel active filter (PAF) is the modern solution for harmonic current
mitigation and reactive power compensation of nonlinear loads. This thesis is
dedicated to detailed analysis, design, control, and implementation of a PAF for a 3-
phase 3-wire rectifier load. Specifically, the current regulator and switching ripple
filter (SRF) are thoroughly investigated. A novel discrete time hysteresis current
regulator with multi-rate current sampling and flexible PWM output, DHCR3, is
proposed. DHCR3 exhibits a high bandwidth while limiting the maximum switching
frequency for thermal stability and its implementation is simple. In addition to the
development of DHCR3, in the thesis state of the art current regulation methods are
considered and thoroughly compared with DHCR3. Since the current regulator type
determines the SRF topology choice, various SRF topologies are considered and a
thorough design study is conducted and SRF topology selection and parameter
determination methods are presented via numerical examples. Through a PAF
designed for a 10kW diode/thyristor rectifier load, the superior performance of
DHCR3 is verified through simulations and experiments and via comparison to other
current regulators. The sufficient switching ripple attenuation of the SRF structures
for the designed PAF system and the overall performance of the designed and built
PAF system are demonstrated via detailed computer simulations and laboratory
experiments. This thesis aids the PAF current regulator and SRF selection, design,
and implementation.
3
Girlevicius, Lukas. "Active magnetic bearing driver circuit design featuring current measurement integration." Thesis, Uppsala universitet, Elektricitetslära, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-269215.
Повний текст джерелаАнотація:
Researchers at Uppsala University are developing a flywheel energy storage device intended to be used in electrical vehicles. Kinetic energy storage technology has potential to make purely electric powertrain both more effective and efficient. While deployment of the third prototype is approaching there has been a request for a more precise and noise-immune circuitry to power active magnetic bearings that hold and stabilise the rotor. A similar circuit designed for powering electromagnets was recently developed at the Uppsala University’s Electricity department and is used as a template in development of the new active magnetic bearing driver circuit. Current measurement integration technique is tested and implemented as a way to increase circuit’s control feedback loop performance. To further boost precision and noise-immunity 0-20 mA current loop signals are adapted as the standard for output signals. Results of this project include a thorough analysis of the electromagnet driver circuit development, implementation of a new current sensing technique including an experimental self-inductance measurement, printed circuit board layout design and a full list of components necessary to power and control two sets of active magnetic bearings consisting of 8 individual electromagnets.
4
Zhang, Yigong. "ACTIVE CURRENT INJECTION METHOD FOR LIMITING GROUND FAULT CURRENT HARMONICS IN UNDERGROUND COAL MINES." UKnowledge, 2014. http://uknowledge.uky.edu/mng_etds/15.
Повний текст джерелаАнотація:
Current practice in U.S. underground coal mine high-voltage distribution systems is to attempt to limit ground fault current to 25 Amperes and de-energize the circuit at 10 Amperes. However, the significant amount of system capacitance due to the use of shielded cables can cause ground fault current to be two or three times the intended ground fault limit. Consequently, this practice can cause several issues such as ground fault currents significantly exceeding the neutral grounding resistor current limit, loss of relay selectivity in the distribution system, and transient overvoltages in certain ground fault situations. These issues are solved to some extent by using a resonance grounded system, currently used in some other countries. However, a shortcoming of traditional resonance grounded systems is the inability to deal with the harmonic components existing in ground fault current. With the increasing use of nonlinear sources such as variable frequency drives, the proportion of harmonic components in ground fault current can be significant. Consequently, although the fundamental component can be almost fully compensated in a traditional resonance grounded system, the harmonic components can still be large enough to maintain arcing and cause personal injury and equipment damage. In this dissertation, a novel method is developed to perform real-time prediction of the harmonics in ground fault currents. Methods for neutralizing the ground fault current harmonics and identifying ground fault location are also developed. Results indicate that the combination of traditional high-resistance grounding and active current injection to neutralize harmonics in the ground fault has the potential to significantly reduce the total ground fault current and reduce arc and flash hazards during ground faults in high voltage distribution systems.
5
Nwaribe, Nicholas. "Active magnet bearings." Thesis, National aviation university, 2021. https://er.nau.edu.ua/handle/NAU/52781.
Повний текст джерелаАнотація:
1. Access mode: https://www.calnetix.com/resource/magnetic-bearings/advantages-magnetic-bearings
2. Access mode: https://www.waukbearing.com/resources/bearing-knowledge/how-active-magnetic-bearings-work.A magnetic bearing is a form of bearing that uses magnetic levitation to support a load. Moving parts are supported by magnetic bearings without any physical contact. For example, they can levitate a spinning shaft and allow relative motion with very little friction and no mechanical wear. Magnetic bearings support the highest speeds of any kind of bearing and have no maximum relative speed.
Магнітний підшипник - це форма підшипника, яка використовує магнітну левітацію для підтримки навантаження. Рухомі деталі підтримуються магнітними підшипниками без будь-якого фізичного контакту. Наприклад, вони можуть піднімати обертальний вал і дозволяти відносний рух з дуже незначним тертям і відсутністю механічного зносу. Магнітні підшипники підтримують найвищі швидкості будь-якого виду підшипників і не мають максимальної відносної швидкості.
6
Lenwari, Wanchak. "High performance current control for shunt active filters using resonant compensators." Thesis, University of Nottingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.439850.
Повний текст джерела
7
Feng, Xiaohu. "Active filter for improving a switched reluctance motor drive's input power quality." Lexington, Ky. : [University of Kentucky Libraries], 2005. http://lib.uky.edu/ETD/ukyelen2005t00346/THESIS2.pdf.
Повний текст джерелаАнотація:
Thesis (M.S.)--University of Kentucky, 2005.Title from document title page (viewed on January 23, 2006). Document formatted into pages; contains: x, 97 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 95-96).
8
Delaney, Eamon John. "Harmonic and interharmonic current distortion in variable frequency synchronous motor drives." Thesis, Staffordshire University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.282140.
Повний текст джерела
9
Palakodety, Atmaram. "CMOS Active Pixel Sensors for Digital Cameras: Current State-of-the-Art." Thesis, University of North Texas, 2007. https://digital.library.unt.edu/ark:/67531/metadc3631/.
Повний текст джерелаАнотація:
Image sensors play a vital role in many image sensing and capture applications. Among the various types of image sensors, complementary metal oxide semiconductor (CMOS) based active pixel sensors (APS), which are characterized by reduced pixel size, give fast readouts and reduced noise. APS are used in many applications such as mobile cameras, digital cameras, Webcams, and many consumer, commercial and scientific applications. With these developments and applications, CMOS APS designs are challenging the old and mature technology of charged couple device (CCD) sensors. With the continuous improvements of APS architecture, pixel designs, along with the development of nanometer CMOS fabrications technologies, APS are optimized for optical sensing. In addition, APS offers very low-power and low-voltage operations and is suitable for monolithic integration, thus allowing manufacturers to integrate more functionality on the array and building low-cost camera-on-a-chip. In this thesis, I explore the current state-of-the-art of CMOS APS by examining various types of APS. I show design and simulation results of one of the most commonly used APS in consumer applications, i.e. photodiode based APS. We also present an approach for technology scaling of the devices in photodiode APS to present CMOS technologies. Finally, I present the most modern CMOS APS technologies by reviewing different design models. The design of the photodiode APS is implemented using commercial CAD tools.
10
Palakodety, Atmaram Mohanty Saraju. "CMOS active pixel sensors for digital cameras current state-of-the-art /." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3631.
Повний текст джерела
11
Tingleff, Jens. "Current Mode Wave Active Filters : a topology for high frequency integrated filters." Thesis, Imperial College London, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.337669.
Повний текст джерела
12
Jassim, Bassim M. H. "Active current sharing control schemes for parallel connected AC/DC/AC converters." Thesis, University of Newcastle upon Tyne, 2014. http://hdl.handle.net/10443/3086.
Повний текст джерелаАнотація:
The parallel operation of voltage fed converters can be used in many applications, such as aircraft, aerospace, and wind turbines, to increase the current handling capability, system efficiency, flexibility, and reliability through providing redundancy. Also, the maintenance of low power parallel connected units is lower than one high power unit. Significant performance improvement can be attained with parallel converters employing interleaving techniques where small passive components can be used due to harmonic cancellation. In spite of the advantages offered by parallel connected converters, the circulating current problem is still a major concern. The term circulating current describes the uneven current sharing between the units. This circulating current leads to: current distortion, unbalanced operation, which possibly damages the converters, and a reduction in overall system performance. Therefore, current sharing control methods become necessary to limit the circulating current in a parallel connected converter system. The work in this thesis proposes four active current sharing control schemes for two equally rated, directly paralleled, AC/DC/AC converters. The first scheme is referred to as a “time sharing approach,” and it divides the operation time between the converters. Accordingly, in the scheme inter-module reactors become unnecessary, as these are normally employed at the output of each converter. However, this approach can only be used with a limited number of parallel connected units. To avoid this limitation, three other current sharing control schemes are proposed. Moreover, these three schemes can be adopted with any pulse width modulation (PWM) strategy and can be easily extended to three or more parallel connected units since they employ a modular architecture. The proposed current sharing control methods are employed in two applications: a current controller for three-phase RL load and an open loop V/f speed control for a three-phase induction motor. The performance of the proposed methods is verified in both transient and steady state conditions using numerical simulation and experimental testing.
13
Bianchi, Jeramie Seth. "Bridgeless Active Power Factor Correction Using a Current Fed Push Pull Converter." DigitalCommons@CalPoly, 2011. https://digitalcommons.calpoly.edu/theses/544.
Повний текст джерелаАнотація:
ABSTRACT
Bridgeless Active Power Factor Correction
Using a Current Fed Push Pull Converter
Jeramie Seth Bianchi
Switched Mode Power Supplies have become increasingly popular for efficient methods of delivering power to an assortment of electronic devices. This thesis proposes a method of using a current fed push pull converter to provide active power factor correction and rectification in a single stage. While most AC-DC converters utilize a bridge rectifier to convert AC-DC and then perform DC-DC conversion, the proposed circuit will utilize its output diodes to perform rectification, thus eliminating the need for a bridge rectifier. This circuit will also inherently provide power factor correction because the input current has a continuous path for current flow due to the current fed topology where no time exists for both switches to be off. Through analog circuitry for the controller, multiple methods of AC main switching are tested, including isolation techniques using optocouplers, to prove the most efficient way to control a bidirectional switch. Simulations with PSPICE and hardware implementation of the design prove that alternative methods to provide quality power conversion for Switched Mode Power Supplies are available.
Keywords: Active Power Factor Correction, Current Fed Push Pull Converter, SMPS, Bidirectional Switching, IGBT, Bridgeless Rectification
14
Pisár, Peter. "Metody návrhu aktivních kmitočtových filtrů na základě pasivního RLC prototypu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2009. http://www.nusl.cz/ntk/nusl-218107.
Повний текст джерелаАнотація:
The aim of this diploma thesis is to design active frequency filters based on passive RLC prototype. Three methods of the design of active filters and active functional blocks of electronic circuits working in current or mixed mode are used to this purpose. These blocks allow to process electrical signals with frequencies up to low tens of megahertz. In addition they feature for instance with high slew rate and low supply voltage power. Active high-pass and low-pass 2nd order filters are designed using simulation of inductor by active subcircuit method. Grounded and subsequently floating synthetic inductor is made with the current conveyors in the first case and with the current operational amplifiers with single input and differential output in the second case. This method advantage is relatively simple design and disadvantage is great quantity of active functional blocks. Active filters based on passive frequency ladder 3rd order filter while only one floating inductor is connected, are designed with circuit equation method. In the first design differential input / output current followers are used and in the second case current-differencing buffered amplifiers are used. This method benefits by smaller active blocks number and disadvantage is more complex design of the active filter. Active filter based on passive prototype of low-pass 3rd order filter with two floating inductors is designed with Bruton transformation method. Final active filter uses current operational amplifiers with single input and differential output which together with other passive elements replace frequency depending negative resistor, which arise after previous Bruton transform. This method usage is advantageous if the design consists of larger quantity of inductors and less number of capacitors. High-pass 2nd order filter is simulated by tolerance and parametrical analyses. Physical realisation utilising current feedback operational amplifier which substitute commercially hardly accessible current conveyors is subsequently made. Measurements of constructed active filter show that additional modifications, which allow better amplitude frequency characteristics conformity, are necessary.
15
Hansmann, Chirstine Henriette. "Active capacitor voltage stabilisation in a medium-voltage flying-capacitor multilevel active filter." Thesis, Stellenbosch : University of Stellenbosch, 2005. http://hdl.handle.net/10019.1/1762.
Повний текст джерелаАнотація:
Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2005.A switching state substitution must be developed that will make use of both single-phase redundancies and three-phase redundancies in the flying-capacitor topology. Losses should be taken into consideration and the algorithm must be designed for implementation on the existing PEC33 system, with on-board DSP (TMS320VC33) and FPGA (EP1K50QC208). The specific power-electronics application is a medium-voltage active filter. Existing capacitor voltage stabilisation schemes are investigated and a capacitor-voltage based algorithm is developed that is investigated in parallel with the Donzel and Bornard algorithm. Detailed simulation models are built for the evaluation of both existing and the proposed algorithm. Three-phase control is also evaluated. Timing analysis of the proposed algorithm shows that a DSP-only implementation of the proposed capacitor-based solution is not feasible. Detail design of the digital controller hereof is implemented in VHDL. Finally, a four-cell controller is fitted into the FPGA. A scalable hardware sorting architecture is utilised.
16
Raju, N. Ravisekhar. "A decoupled converter topology for active compensation of power systems /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/5847.
Повний текст джерела
17
Zhou, Chen. "Design and analysis of an active power factor correction circuit." Thesis, Virginia Polytechnic Institute and State University, 1989. http://hdl.handle.net/10919/53729.
Повний текст джерелаАнотація:
The design of an active-unity power factor correction circuit with variable-hysteresis
control for off-line dc-to-dc switching power supplies is described. Design
equations relating the boost inductor current ripple to the circuit components selection
and circuit performance arc discussed. A computer-aided design program (CADO) is
developed to give the optimal circuit components selection. A 500 watt, 300 volt experimental
circuit is built to verify the simulation and analysis results.
The control-to-output response of the power factor circuit is verified with the experimental
results. Design guidelines for the low-frequency feedback network are presented.
Small-signal closed-loop responses are measured with an experimental power
factor circuit.Master of Science
18
Zupfer, Joel E. "Optimal adaptive estimation algorithm for harmonic current reduction using power limited active line conditioners." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1993. http://handle.dtic.mil/100.2/ADA277354.
Повний текст джерелаАнотація:
Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, December 1993.Thesis advisor(s): Ashton, Robert W. ; Cristi, Roberto. "December 1993." Includes bibliographical references. Also available online.
19
Gous, Marthinus Gerhardus Faculin. "Shunt active power filtering algorithms for unbalanced, non-linear loads." Thesis, Stellenbosch : Stellenbosch University, 2003. http://hdl.handle.net/10019.1/53589.
Повний текст джерелаАнотація:
Thesis (MScEng)--University of Stellenbosch, 2003.ENGLISH ABSTRACT: This thesis presents the design and implementation of shunt active power filtering algorithms for unbalanced, non-linear loads. A three-phase four-wire topology is developed in the dqO space. Based on this development an accurate dynamic system model, taking into account the effect of the neutral inductor is developed. The synchronous reference frame technique is expanded to enable the isolation of the zero sequence current component into its instantaneous active and reactive current components. Additionally a prediction method is proposed that will enable the proper prediction of the reference currents in a threephase four-wire system. Two categories of reference current signal tracking algorithms are investigated; namely the predictive current controller and the sliding mode current controller. A compensating technique is proposed to compensate for the effects that sampling and computational time delay have on the performance of the system. Additionally, an investigation is done into the effect that dead-time has on the performance of the system, and based on this investigation a dead-time compensating strategy is proposed. Finally simulation and practical results are provided to validate the discussed theories.
AFRIKAANSE OPSOMMING: Hierdie verhandeling ondersoek die ontwerp en implementering van parralel gekoppelde aktiewe filter algoritmes vir ongebalenseerde, nie-lineêre laste. 'n Drie-fase vier-draad topologie, asook 'n korrekte model van die dinamiese sisteem, wat die effek van die neutraal induktor insluit, is ontwikkel in die dqO ruimte. Die sinchroon verwysing vlak tegniek is uitgebrei om die isolering van die nul sekwensie stroom in onderskeidelik die oombliklike aktiewe en reaktiewe stroom komponente te verdeel. Addisioneel is a vooruitskatting tegniek aanbeveel wat die beheerder in staat sal stelom voldoende die verwysing strome vooruit te skat in 'n drie-fase vier-draad stelsel. Twee katagoriee van verwysing stroom volging algoritmes is ondersoek, naamlik die afskatting stroom beheerder en die gleiende modus stroom beheerder. 'n Effektiewe kompensasie tegniek is voorgestel om die effek van tydvertraging as gevolg van monstering en verwerking te elimineer. Addisioneel is die effek van dooie-tyd ondersoek en gebasseer op hierdie ondersoek is 'n effektiewe dooie-tyd kompensasie tegniek voorgestel. Laastens is simulasies en praktiese resultate verskaf om die werking van die voorgestelde teorie te bevestig.
20
陳卓雄。 and Chuk-hung Chan. "Design and evaluation of active power factor correction circuit operation in discontinuous inductor current mode." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1999. http://hub.hku.hk/bib/B31220344.
Повний текст джерела
21
Grobler, Andries Johannes. "A low cost eddy current displacement sensor for active magnetic bearings / by Andries J. Grobler." Thesis, North-West University, 2008. http://hdl.handle.net/10394/2627.
Повний текст джерелаАнотація:
The McTronX research group of the North-West University is involved in active magnetic bearing (AMB) research. An AMB is a mechatronic system that levitates a rotating axis with electromagnetic forces. The group has successfully implemented radial and axial AMBs as well as a complete flywheel energy storage system operating at 22 000 rpm. Research is also done on using the actuator voltage and current to derive rotor position, also known as self-sensing, but these methods have not been perfected. Position measurement is very important in AMBs, since it is the main control variable. The literature indicates that the eddy current phenomenon is well suited for displacement measurement, since it is relatively noise immune and insensitive to process medium when a nonmagnetic and non-conductive substance is used. Printed circuit board (PCB) sensors must be considered when low cost is a requirement. The goal of this project is to design, simulate, manufacture and test a PCB based, low cost eddy current displacement sensor for AMBs. This project will focus on the sensor (probe) that converts the physical rotor movement to an electric signal. An evaluation platform, used to test the PCB sensor, is also designed and manufactured as part of this project.
The first step in the sensor design is to establish a suitable software model. A finite element
method (FEM) software package, Comsol® , is used to realise a FEM model of the sensor. This FEM model is used to simulate sensor behaviour in various configurations. The trends found in the FEM model results are used to compile a design flow diagram. This diagram is illustrated by applying it to single, double- and five-layer designs. The single- and double-layer sensors are manufactured and tested to validate the accuracy of the FEM model and design flow diagram. Close correlation between the practical and predicted results is found for the single- and double layer sensors. The sensitivity and working point rms voltage correlated exceptionally well for both sensors. Linearity does not correlate as closely due to the evaluation platform and circuitry but is still within acceptable limits when compared to other displacement sensors used in AMBs. This project laid the foundation for PCB sensor design in the McTronX group. A comparison between the different sensors showed that the double-layer sensor is the best choice in terms of cost and performance. It is concluded that the PCB displacement sensor presented in this dissertation is a viable low cost option for displacement measurement in AMBs.The McTronX research group of the North-West University is involved in active magnetic bearing (AMB) research. An AMB is a mechatronic system that levitates a rotating axis with electromagnetic forces. The group has successfully implemented radial and axial AMBs as well as a complete flywheel energy storage system operating at 22 000 rpm. Research is also done on using the actuator voltage and current to derive rotor position, also known as self-sensing, but these methods have not been perfected. Position measurement is very important in AMBs, since it is the main control variable. The literature indicates that the eddy current phenomenon is well suited for displacement measurement, since it is relatively noise immune and insensitive to process medium when a nonmagnetic and non-conductive substance is used. Printed circuit board (PCB) sensors must be considered when low cost is a requirement. The goal of this project is to design, simulate, manufacture and test a PCB based, low cost eddy current is placement sensor for AMBs. This project will focus on the sensor (probe) that converts the physical rotor movement to an electric signal. An evaluation platform, used to test the PCB sensor, is also designed and manufactured as part of this project. The first step in the sensor design is to establish a suitable software model. A finite element method (FEM) software package, Comsol, is used to realise a FEM model of the sensor. This FEM model is used to simulate sensor behaviour in various configurations. The trends found in the FEM model results are used to compile a design flow diagram. This diagram is illustrated by applying it to single, double- and five-layer designs. The single- and double-layer sensors are manufactured and tested to validate the accuracy of the FEM model and design flow diagram. Close correlation between the practical and predicted results is found for the single- and double layer sensors. The sensitivity and working point rms voltage correlated exceptionally well for both sensors. Linearity does not correlate as closely due to the evaluation platform and circuitry but is still within acceptable limits when compared to other displacement sensors used in AMBs. This project laid the foundation for PCB sensor design in the McTronX group. A comparison between the different sensors showed that the double-layer sensor is the best choice in terms of cost and performance. It is concluded that the PCB displacement sensor presented in this dissertation is a viable low cost option for displacement measurement in AMBs.
Thesis (M.Ing. (Electrical Engineering)--North-West University, Potchefstroom Campus, 2008.
22
Chan, Chuk-hung. "Design and evaluation of active power factor correction circuit operation in discontinuous inductor current mode /." Hong Kong : University of Hong Kong, 1999. http://sunzi.lib.hku.hk/hkuto/record.jsp?B2062315X.
Повний текст джерела
23
Combrink, Frederik Wilhelm. "Analysis and synthesis of an active resonant snubber for high-power IGBT converters." Thesis, Stellenbosch : Stellenbosch University, 2001. http://hdl.handle.net/10019.1/52090.
Повний текст джерелаАнотація:
Thesis (MScEng)--University of Stellenbosch, 2001.ENGLISH ABSTRACT: This thesis describes the study of two soft-switching inverter topologies that are well suited to high-power applications. For the first topology, namely an active resonant turn-off snubber, the existing theory is expanded with a detailed study into operation strategies and topology protection. This is followed by an investigation into the second topology, which is a combined snubber that reduces both turn-off and turn-on losses. The investigation involves a detailed analysis of the losses in the snubber components and main devices, as well as a study into the effects of parasitic components and diode reverse recovery on the operation of the snubber. Based on this theory a snubber optimisation procedure is also developed. Possible operation strategies and protection techniques were also evaluated for this topology. Single-phase experimental inverters were used to verify the basic operation theory and switching loss prediction for both topologies. The thesis is concluded by the design and construction of a practical soft-switching threephase inverter. After implementation the experimental inverter is used for theory verification.
AFRIKAANSE OPSOMMING: Hierdie proefskrif beskryf die ondersoek na twee saggeskakelde omsetter topologieë wat veral geskik is vir hoë-drywing toepassings. Die bestaande teorie aangaande die eerste topologie, naamlik 'n aktiewe, resonante, afskakel gapser, word uitgebrei met 'n deeglike-studie oor bedryfstegnieke en beskermingsmetodes. Vervolgens word 'n gekombineerde gapser topologie, wat beide aanskakel- en afskakelverliese verminder, ondersoek. Die studie behels 'n volledige analise van die verliese in die omsetter en gapser komponente en die invloed van parasitêre komponente en diode tru-herstel. Hierdie teorie word ook gebruik om 'n optimale gapser ontwerp prosedure te ontwikkel. Die moontlikke bedryfstegnieke en beskermingsmetodes word ook vir hierdie topologie evalueer. In albei gevalle is eksperimentele, enkelfase omsetters gebruik om die teorie oor basiese werking en skakelverlies vermindering te verifieer. Die ondersoek word afgesluit deur die ontwerp en konstruksie van 'n praktiese, saggeskakelde, drie-fase omsetter te beskryf. Na implimentering van die omsetter word volledige eksperimentele verifikasie uitgevoer.
24
González, Rubio Jesús. "On the effective deployment of current machine translation technology." Doctoral thesis, Universitat Politècnica de València, 2014. http://hdl.handle.net/10251/37888.
Повний текст джерелаАнотація:
Machine translation is a fundamental technology that is gaining more importance
each day in our multilingual society. Companies and particulars are
turning their attention to machine translation since it dramatically cuts down
their expenses on translation and interpreting. However, the output of current
machine translation systems is still far from the quality of translations generated
by human experts. The overall goal of this thesis is to narrow down
this quality gap by developing new methodologies and tools that improve the
broader and more efficient deployment of machine translation technology.
We start by proposing a new technique to improve the quality of the
translations generated by fully-automatic machine translation systems. The
key insight of our approach is that different translation systems, implementing
different approaches and technologies, can exhibit different strengths and
limitations. Therefore, a proper combination of the outputs of such different
systems has the potential to produce translations of improved quality.
We present minimum Bayes¿ risk system combination, an automatic approach
that detects the best parts of the candidate translations and combines them
to generate a consensus translation that is optimal with respect to a particular
performance metric. We thoroughly describe the formalization of our
approach as a weighted ensemble of probability distributions and provide efficient
algorithms to obtain the optimal consensus translation according to the
widespread BLEU score. Empirical results show that the proposed approach
is indeed able to generate statistically better translations than the provided
candidates. Compared to other state-of-the-art systems combination methods,
our approach reports similar performance not requiring any additional data
but the candidate translations.
Then, we focus our attention on how to improve the utility of automatic
translations for the end-user of the system. Since automatic translations are
not perfect, a desirable feature of machine translation systems is the ability
to predict at run-time the quality of the generated translations. Quality estimation
is usually addressed as a regression problem where a quality score
is predicted from a set of features that represents the translation. However, although the concept of translation quality is intuitively clear, there is no
consensus on which are the features that actually account for it. As a consequence,
quality estimation systems for machine translation have to utilize
a large number of weak features to predict translation quality. This involves
several learning problems related to feature collinearity and ambiguity, and
due to the ¿curse¿ of dimensionality. We address these challenges by adopting
a two-step training methodology. First, a dimensionality reduction method
computes, from the original features, the reduced set of features that better
explains translation quality. Then, a prediction model is built from this
reduced set to finally predict the quality score. We study various reduction
methods previously used in the literature and propose two new ones based on
statistical multivariate analysis techniques. More specifically, the proposed dimensionality
reduction methods are based on partial least squares regression.
The results of a thorough experimentation show that the quality estimation
systems estimated following the proposed two-step methodology obtain better
prediction accuracy that systems estimated using all the original features.
Moreover, one of the proposed dimensionality reduction methods obtained the
best prediction accuracy with only a fraction of the original features. This
feature reduction ratio is important because it implies a dramatic reduction
of the operating times of the quality estimation system.
An alternative use of current machine translation systems is to embed them
within an interactive editing environment where the system and a human expert
collaborate to generate error-free translations. This interactive machine
translation approach have shown to reduce supervision effort of the user in
comparison to the conventional decoupled post-edition approach. However,
interactive machine translation considers the translation system as a passive
agent in the interaction process. In other words, the system only suggests translations
to the user, who then makes the necessary supervision decisions. As
a result, the user is bound to exhaustively supervise every suggested translation.
This passive approach ensures error-free translations but it also demands
a large amount of supervision effort from the user.
Finally, we study different techniques to improve the productivity of current
interactive machine translation systems. Specifically, we focus on the development
of alternative approaches where the system becomes an active agent
in the interaction process. We propose two different active approaches. On the
one hand, we describe an active interaction approach where the system informs
the user about the reliability of the suggested translations. The hope is that
this information may help the user to locate translation errors thus improving
the overall translation productivity. We propose different scores to measure translation reliability at the word and sentence levels and study the influence
of such information in the productivity of an interactive machine translation
system. Empirical results show that the proposed active interaction protocol
is able to achieve a large reduction in supervision effort while still generating
translations of very high quality. On the other hand, we study an active learning
framework for interactive machine translation. In this case, the system is
not only able to inform the user of which suggested translations should be
supervised, but it is also able to learn from the user-supervised translations to
improve its future suggestions. We develop a value-of-information criterion to
select which automatic translations undergo user supervision. However, given
its high computational complexity, in practice we study different selection
strategies that approximate this optimal criterion. Results of a large scale experimentation
show that the proposed active learning framework is able to
obtain better compromises between the quality of the generated translations
and the human effort required to obtain them. Moreover, in comparison to
a conventional interactive machine translation system, our proposal obtained
translations of twice the quality with the same supervision effort.González Rubio, J. (2014). On the effective deployment of current machine translation technology [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/37888
TESIS
25
Terciyanli, Alper. "Design And Implementation Of A Current Source Converter Based Active Power Filter For Medium Voltage Applications." Phd thesis, METU, 2010. http://etd.lib.metu.edu.tr/upload/12611767/index.pdf.
Повний текст джерелаАнотація:
This research work is devoted to the design, development and implementation of a Current Source Converter (CSC) based Active Power Filter (APF) for Medium Voltage (MV) applications. A new approach has been proposed to the design of the CSC based APF for reducing the converter kVA rating considerably. This design approach is called the Selective Harmonic Amplification Method (SHAM), and is based on the amplification of some selected harmoniccurrent components of the CSC by the input filter, and the CSC control system, which is specifically designed for this purpose. The proposed SHAM has been implemented on the first industrial CSC based APF for the elimination of 11th and 13th current harmonics of 12-pulse rectifiers fed from Medium Voltage (MV) underground cables in order to comply with IEEE Std. 519-1992. 450 kVA rated APF with only 205 kVA CSC rating has been connected to the MV bus via a coupling transformer of 600kVA, 34.5/1.1 kV. The power stage of the CSC based APF is composed of water-cooled high voltage IGBT and diode modules. Reference currents to be generated by the CSC are obtained by the use of a selective harmonic extraction method, by mploying synchronously rotating reference frames for each selected harmonic component. An Active damping method is also used to suppress the oscillations around the natural frequency of the input filter, excluding the harmonic components to be eliminated by APF. Simulation and field test results have shown that SHAM can successfully be applied to a CSC based APF for reduction of converter kVA rating, thus making it a cost- competitive alternative to voltage source converter based APFs traditionally used in industry applications.
26
Lai, Chien-Tsung, and 賴健宗. "HYSTERESIS-CURRENT-CONTROLLED CLASS-D AMPLIFIER WITH ACTIVE CURRENT SENSING TECHNIQUES." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/03439832355051947277.
Повний текст джерелаАнотація:
碩士龍華科技大學
電子系碩士班
94
A hysteresis-current-controlled (HCC) class-D amplifier with active current sensing techniques is presented in this thesis. The proposed active current sensing circuit uses no passive elements to fully measure the bi-direction inductive load current in class-D amplifier. A hysteresis-current-controller is then used to control the measured current follow a reference signal. The entire circuit contain an error amplifier, a hysterrsis-current-controlled circuit, a sample -and-hold circuit, an active current sensing circuit, a driver circuit……etc. The details of the entire circuit will be described thoroughly in this thesis. The class-D amplifier has been fabricated with TSMC 3.3-V, 0.35-μm double-poly quadruple-metal CMOS technology.
27
Wang, Hung Yu, and 王鴻猷. "Impedence smulators employing active current-mode elements." Thesis, 1993. http://ndltd.ncl.edu.tw/handle/58617299295362376030.
Повний текст джерелаАнотація:
碩士中原大學
電機工程研究所
81
A current-mode approach, involving active current-mode elements, is playing an increasing important role in the development of many new high-performance circuits. Therefore, this research has focused on the design of impedance simulatots by using active current-mode elements. In this study, we present (1) a simplified circuit for the realization of series impedance simulators employing a single second-generation current conveyor (CCII) and only six passive elements which can drive twelve types of series impedances; (2) three novel configurations for the realization of any type of impedance simulators employing two CCIIs; and (3) a method for the realization of some floating single-term impedance simulators according to the nullor model of generalized immittance converter(GIC).
28
Chen, Chih-Chiang, and 陳志強. "Hysteresis-Current-Controlled Buck/ Buck-Boost Converter Using Active Current Sensing Circuit." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/7q3egk.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
電腦與通訊研究所
94
In this thesis, We design a new active current sensing circuit and apply this technology fo hysteresis-current-controlled buck/buck-boost converter using active current sensing circuit for portable applications. In the proposed DC-DC converter, the key building blocks includes power MOS, Voltage-current conversion circuit, hysteresis-current comparator, driving circuit, non-overlapping circuit and current sensing circuit. The current sensing circuit can fully sense the inductor current and be used to construct buck/buck-boost converter. The hysteresis-current-controlled can be worked in parallel. The proposed circuits have been designed with TSMC 0.35um DPQM CMOS processes. The experimental results show that the buck/ buck-boost converter works well with the following features: the maximum inductor current up to 750mA; the input voltage range is 3~6V; the output voltage range from 0.45 to input voltage-0.4V; the maximum power efficiency up to 93.6%.
29
Yang, Ssu-Che, and 楊思哲. "Design of Voltage-Mode Tunable Active Filter Based on Current-Mode Active." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/mbr3n2.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
電腦與通訊研究所
96
The key point of major research of this thesis is that the author uses the linear transformation method to design the low-pass tunable bandwidth active filter. This thesis can be divided into three parts. The first part of this thesis is to implement a 6th-order Butterworth low-pass filter using second generation current conveyors with TSMC 0.35μm 2P4M technology. The power supply is ±1.65V, the power consumption is 30.7mW, and the chip area is 0.168588mm2. The second part of this thesis is to implement a 6th-order tunable Butterworth low-pass filter using digitally controlled method that achieved the bandwidth of active filter can be tuned to control second generation current conveyors with TSMC 0.18μm 1P6M technology. The tunable bandwidth of active filter is about 11KHz to 1.44MHz. The power supply and the power consumption are ±0.9V and 5.54mW, and the chip area is 0.359296mm2. The third part of this thesis is to implement a 6th-order tunable Butterworth low-pass filter using the another active component called the differential difference current conveyor and uses digitally controlled method to control differential difference current conveyors to achieve the purpose that the bandwidth of active filter can be tuned with TSMC 0.18μm 1P6M technology. The tunable bandwidth of active filter is about 14KHz to 2.62MHz. The power supply and the power consumption are 1.8V and 3.64mW, and the chip area is 0.31515mm2 without PAD circuits.
30
Chen, Jian-Hao, and 陳建豪. "Constant-Frequency Hysteresis-Current-Controlled DC-DC Converter with Active-Current-Sensing Techniques." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/3j6734.
Повний текст джерела
31
Lin, Chang-Ching, and 林長青. "The Universal Filter Employing Current-Mode Active Elements." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/46930948861819414536.
Повний текст джерелаАнотація:
碩士中原大學
電子工程研究所
92
Abstract This thesis mainly discusses the applications of current-mode active elements. One of the applications is the structures of current-mode universal filters, and the other is the designing method of a filter. It’s proposed two new universal filters. The first one is a voltage-mode universal filter, and the second one is a universal filter with current input applying KHN (Kerwin-Huelsman-Newcomb) configuration. In this thesis, the Differential Difference Current Conveyors (DDCC’s) are used to realize the first proposed filter circuit structure. The proposed universal filter employs two-integrator Loop structure and signal flow diagram method to collocate transmission-zeros rule for explaining the design and the principle of the filter. Hspice simulator applying UMC 0.5μm 2P2M process parameter is used to simulate the characteristics and feasibility of the proposed circuit. The passive elements of the circuit are all grounded and suitable for high frequency operation and monolithic chip implementation. The second part of the thesis introduces the process of designing impedance simulators and circuits of negative resistors. Simulation results of the negative resistor circuit are used to examine the principle. Finally, this thesis employs Current Feedback Amplifier (CFA) and Current Differencing Buffered Amplifier (CDBA) to synthesize the proposed new KHN filter and construct the configuration using signal flow diagram. Hspice simulation results of the proposed KHN universal filter coincide with the theoretical results.
32
Liu, Zheng-Yang, and 劉政昜. "New Buck Converters with Active-Current-Sensing Circuits." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/5yea94.
Повний текст джерелаАнотація:
碩士國立臺北科技大學
電子工程系
106
The thesis proposes a pseudo-current mode buck converter with Operational Transconductance Amplifier-Capacitor (OTA-C)-current-sensing circuit and an adaptive on-time buck converter with active-current-sensing circuit. The first proposed converter is a pseudo-current mode buck converter with OTA-C-current sensing circuit. The proposed OTA-C-current-sensing circuit does not produce current spike, so the proposed converter does not need a sample and hold circuit to eliminate current spike. The circuit is implemented with TSMC 0.35µm CMOS process, and the total chip area is 1.494 × 1.472 mm2. The input voltage range is from 3 V to 3.6 V and the output voltage range is from 1 V to 2.5 V. The switching frequency of the proposed buck converter is 1MHz. The load transient response time is about 2 µs when the load current changes from 100 mA to 500 mA and from 500 mA to 100 mA. When the output voltage is 2.5 V and the output current is 250 mA, the converter has the highest efficiency of 91.14%. The second proposed converter is an adaptive on-time buck converter with active-current-sensing circuit. This proposed new active current sensing circuit senses the inductor current, and compares the current error compensation path directly with the path of the inductor current sensing circuit. It can achieve fast transient response and high power switching efficiency. The circuit is implemented with TSMC 0.35µm CMOS process, and the total chip area is 1.498 × 1.451 mm2. The input voltage range is from 3 V to 3.6 V and the output voltage range is from 1 V to 2.5 V. The switching frequency of the proposed buck converter is 1MHz. The load transient response time is about 4 µs and 3 µs when the load current changes from 50 mA to 500 mA and from 500 mA to 50 mA, respectively. When the output voltage is 2.5 V and the output current is 250mA, the converter has the highest efficiency of 90.6%.
33
Tsai, Chia-Jung, and 蔡佳容. "Dynamic Optimal Current Modulation for Active Power Conditioners." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/44852224185797598845.
Повний текст джерелаАнотація:
碩士國立臺灣大學
電機工程學研究所
103
A dynamic optimal ac line current modulation (DOCM) method for the active power conditioner (APC) is proposed in this thesis. The proposed DOCM method is able to determine the appropriate input current to stabilize the dc-bus voltage as soon as an abrupt power change of the APC occured. By adopting the proposed method, the dc-bus voltage fluctuation can be minimized while providing the feasibility of the dc-bus capacitance reduction. On the other hand, in order to regulate the voltage variation under different power changing scenarios, the regulating slope of the dc-bus voltage under different operating conditions are discussed. Mathematical equations for the proposed DOCM method are derived thoroughly in this paper. Besides, a Controller Area Network (CAN) communication interface is developed for the system monitoring and the power flow control between two micro-grids. Finally, experimental measurements obtained from a 5kVA prototype circuit are presented to verify the performances of the proposed DOCM method.
34
Liu, Cheng-Chia, and 劉政佳. "Active-Clamp Forward Converter with Current Ripple Reduction." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/01282030322079346444.
Повний текст джерелаАнотація:
碩士國立臺灣科技大學
電機工程系
97
A novel low input-current ripple topology named Active-Clamp Forward Converter with Current Ripple Reduction (ACFRR) is proposed in this thesis. In addition to having lower input current ripple and more than 50% duty cycle operation, the fundamental component intensity of the ACFRR’s input current waveform can be reduced by designing the circuit with its embedded filter. To demonstrate ACFRR’s feasibility, the operational principle, simulation and experimental results of the proposed converter operated at 150 kHz switching frequency, 36-75V input and 5V/30A output are presented and its highest efficiency is 84.88%. Moreover, the conversion efficiency of the ACFRR can be further improved by applying the synchronous rectification. According to the experimental results, the highest efficiency, 86.69% of the synchronous rectification ACFRR is achieved.
35
Lin, I.-Pin, and 林逸斌. "Adjoint Filter Realization with Current-Mode Active Elements." Thesis, 2005. http://ndltd.ncl.edu.tw/handle/90460562221453084494.
Повний текст джерелаАнотація:
碩士國立高雄應用科技大學
電子與資訊工程研究所碩士班
93
The implementation of analog signal processing systems in the current domain offers the potential advantages of higher bandwidth capability, less circuit complexity, wider dynamic range, and higher operating speed. Consequently, current-mode approach has been accepted as an alternative mean besides the traditional voltage-mode circuits. It is playing an increasing important role in the development of many new high-performance circuits for signal processing application. In addition, current-mode active devices, which comprise voltage and current variables in their port relations of input and output, have been proved to possess favorable balance of operational flexibility and simplicity over their conventional op-amp counterparts. They are suitable to operate with signals in current-mode and in voltage-mode, rapidly gaining the acceptance of researchers as building blocks in high-performance circuit designs. In this thesis, we proposed all of the current conveyor adjoint elements by using multi-output universal current conveyor. Two biquad filters and their dajoint filters also been proposed by using multi-output universal current conveyor as well as adjoint transform. The cascadability have been considered in the filters design, the filters have these advantages: less passive elements, low sensitivities and grounded capacitors that is very suitable for monolithic implementation. The Simulation result also verified with HSpice and TSMC 0.35μm 2P4M CMOS technology spice model.
36
Hung, Chih-Wen, and 洪志文. "Design of active filters and oscillators using active Multi-Output Current-Mode elements." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/17552621088377983244.
Повний текст джерелаАнотація:
碩士中原大學
電機工程研究所
90
Abstract This paper will be verified that the circuits constructed by current-mode multi-output active elements have the advantages of less number of active and passive element, less power dissipation and simpler configuration than those proposed before as well as low active and passive sensitivities. Especially in 21th-century, the first requirement of circuit design is simple and with many functions in construction. Therefore, traditional current-mode single-output active element will be not powerful again. In this thesis, we successfully present seven multifunction current/voltage-mode biquadratic filters, two current-mode first-order filters, and two oscillators employing current-mode active devices such as operational transconductance amplifier (OTA), second-generation current conveyor (CCII), current-controlled current conveyor (CCCII), third-generation current conveyor (CCIII), and fully differential second-generation current conveyor (FDCCII). “No requirement of critical component matching conditions”, very low active and passive sensitivities, two grounded capacitors ideal for integration, and the simplest structure with minimum components (only for the first circuit) are the advantageous features of all the proposed filters and oscillators. In the part of current-mode universal biquadratic filters: First, a new universal current-mode biquad with two inputs and three outputs or three inputs and single output using one second-generation current conveyor and one third-generation current conveyor is presented. The proposed circuit has two inputs and three outputs and can simultaneously realize low-pass, band-pass, and notch responses. The structure, which has all the passive elements be grounded and two grounded capacitors ideal for integration, presents low sensitivities, high output impedance and no requirement of any critical component matching condition. Secondly, a new current-mode current-controlled universal filter with two inputs and three outputs or three inputs and single output is presented. The proposed circuit uses two plus-type current controlled conveyors (CCCIIs) and two grounded capacitors which can simultaneously realize low-pass, band-pass, and notch filter functions with high output impedances. Moreover, the circuit enjoys orthogonal current control of the parametersω0 and ω0/Q without using passive resistors. Thirdly, a novel four inputs and five outputs current-mode universal biquadratic filter with high-output impedance using one plus-type OTA and one plus-type CCCII is presented. The proposed circuit uses two grounded capacitors and can be electronically adjusted. It can simultaneously realize five generic filter functions with high output impedances, and doesn’t need any component matching conditions. The use of only plus-type active elements simplifies the circuit configuration. Finally, a new universal current-mode biquad with two inputs and three outputs or three inputs and single output using only one fully different second-generation current conveyor and four grounded passive elements is proposed. The proposed circuit has the following advantageous features: realization of five generic current-mode filter signals from the same configuration, no requirements of any cancellation constraints, employment of two grounded capacitors ideal for integrated circuit implementation, employment of two grounded resistors suitable for voltage control, orthogonal adjustment of ω0/Q andω0 through two separate grounded resistors, high output impedance good for cascadability, and very low active and passive sensitivities. In the part of current-mode first-order filter: New canonical first-order all-pass filters with three inputs and three outputs based on one current controlled current conveyor and one operational transconductance amplifier are proposed. The proposed first-order all-pass filters employ only a single active element and a bare minimum number of one grounded capacitor. Both of them are electronically adjusted. It should be noted that the proposed filters can simultaneously realize inverting and non-inverting all-pass signal. In the part of voltage-mode multifunction/universal biquadratic filters: A voltage-mode low-pass, band-pass, high-pass, and notch filter with single input and four outputs, employing the minimum components: only one fully differential second-generation current conveyor (FDCCII), two grounded capacitors and two grounded resistors, is proposed. The proposed circuit offers the following advantageous features: realization of voltage-mode low-pass, band-pass, high-pass, and notch filter responses from the same configuration; no requirement of critical component matching conditions; employment of grounded resistors good for adjustment; orthogonal control of ω0/Q andω0 through two separate grounded resistors, high input impedance good for cascadability, and very low active and passive sensitivities. A new universal voltage-mode biquad with two inputs and three outputs or three inputs and two outputs using only one fully different second-generation current conveyor and four passive elements is proposed. The proposed circuit can realize five generic signals. Moreover, it offers the same advantages features as the last one. In the part of oscillators: We have shown that a fully differential second-generation current conveyor (FDCCII) is so versatile that the single-resistance-controlled oscillators (SRCOs) have the perfect configuration: “fully grounded passive components” in addition to the single active building block (ABB). The proposed oscillators offer the following advantageous: employment of three grounded resistors for ease of adjustment, independent frequency control through a single grounded resistor, employment of two grounded capacitors ideal for integration, ease of convertibility into a voltage-controlled oscillator, current-mode output signal with high output impedance, and very good frequency stability. The last part of the paper is concentrated on the realization of a new sinusoidal oscillator by using two plus-type OTAs and two grounded capacitors. The proposed oscillators offer the following advantageous: Use of grounded capacitors beneficial to IC implementation, independent frequency control through the bias current IB1 and IB2, simple oscillation condition and very high output impedance. The feasibility and accuracy of the proposed circuit are verified very well by using Pspice and Matlab simulations.
37
Ming-Chieh, Lee, and 李明杰. "Design of active filters and oscillators using active dual-output current-mode elements." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/86587439045119759516.
Повний текст джерелаАнотація:
碩士中原大學
電機工程研究所
86
It has been verified that the circuits constructed by active current-mode elements have the advantages of higher signal bandwidths, larger dynamic range,greater linearity, less power dissipation and simpler circuit structure. However, the active current-mode elements with a single output have never been satisfied by the circuit designer gradually, because we must use additional active and passive elements to duplicate currents. Therefore, in this thesis, we use three kinds of active dual-output current-mode elements: dual-output CCII(dual output second-generation current conveyor), dual-output CCCII(dual-output second-generation current controlled conveyor), and dual-output OTA(dual outpuoperational transconductance amplifier), to design several simpler universal f ilter and a single oscillator . On the design of filters and oscillators, themethod adoptted in this thesis all begin with the relationship of the matrix equation . Through the variation of the elements of the admittance matrix, we can get thedesired transfer function. In this thesis, we use three kinds of dual output elements: dual-output CCII, dual-output CCCII, and dual-output OTA, to realize the circuits by using the synthesis techniques: Nullator-Norator oror Nullator-Current Mirror transformations. We use the method to design nine filters and one oscillator, which are :I. Three filters using the dual-output CCII: 1. Universal current-mode filters with one input and three outputs, 2. Universal current-mode filters with three inputs and one output, 3. Multifunction voltage-mode filters with one input and three outputs, with the following advantageous features : i. realize three or five filtering functions simultaneously, ii. reduce the number of active and passive elements in these circuits, iii. employ grounded capacitors ideal for integration, iv. enjoy low active and passive sensitivities. II. Three filters using the dual-output CCCII:1. Universal current-mode filters with one input and three outputs,2. Universal current-mode filters with three inputs and one output, 3. Multifunction voltage-mode filters with one input and three outputs, with the following advantageous features : i. realize three or five filtering functions simultaneously, ii. reduce the number of active and passive elements in these circuits,iii. employ grounded capacitors ideal for integration, iv. employ no passive resistors. III. Three filters using the dual-output OTA:1.Universal current-mode filters with three inputs and one output, 2. Multifunction voltage-modefilters with one input and three outputs, 3. Universal voltage-mode filters with three inputs and one output, with the following advantageous features : i. realize three or five filtering functions simultaneously,ii. reduce thenumber of active and passive elements in these circuits, iii. employ groundedcapacitors ideal for integration, iv. employ no passive resistors, IV. One oscillator using the dual-output OTA: with the following advantageous features: i. control the condition and the frequency of oscillation independently through the bias current of thecorresponding OTA, ii. reduce the number ofactive and passive elements in thecircuit, iii. employ grounded capacitorsideal for integration, iv. employ no passive resistors. In this thesis, we prove the feasibility and accuracy of these circuits by Pspice. The simulation results of these circuits all agree with the theoretical predictions.
38
Ma, Hao Che, and 馬浩哲. "Investigation of Active Damping Technique Using Capacitor Current Feedback for Active Power Filter." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/cqkr8e.
Повний текст джерела
39
Wang, Cao-Hsiung, and 王照雄. "The design of active filters and sinusoidal oscillators using active current-mode elements." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/21529624316340940073.
Повний текст джерела
40
"Active Power Filters for current harmonics and reactive powercompensation." Tese, Biblioteca Digital de Teses e Dissertações da UFPE, 2006. http://www.bdtd.ufpe.br/tedeSimplificado//tde_busca/arquivo.php?codArquivo=115.
Повний текст джерела
41
Chiang, Chih-Wei, and 江致緯. "Design of low voltage active circuits of current mode." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/40135456623240427835.
Повний текст джерелаАнотація:
碩士中原大學
電子工程研究所
90
The aim of this thesis is to design a low voltage CMOS rail-to-rail fully differential operational amplifier, Second-Generation Current conveyor (CCII), Current feedback amplifier (CFA) and Balanced output transonductor (BOTA). The power supply of the rail-to-rail fully operational amplifier, CCII, CFA and BOTA are only +1.5V. Its input stage is composed of an NMOS differential pair a PMOS differential pair. This operational amplifier has a dc gain of 66dB, a unity-gain bandwidth of 2.1MHz and a phase margin of 64.6o. This CCII has bandwidth of voltage follower of 100MHz and bandwidth of current follower is 100MHz. This BOTA has bandwidth of 100MHz. We used the tools of CAD of Cadence to layout and verify. Those circuit have been fabricated with standard COMS IC process of n-well 0.5μm double poly double metal. Full custom design flow has been used in thesis. And HSPICE simulation results are preformed using level 49 model of 0.5μm CMOS process. There are several methods design electrical parameter had been introduced.
42
Lin, Yu-Hsin, and 林祐忻. "Design of analog filters employing current-mode active components." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/61078613951799190676.
Повний текст джерелаАнотація:
碩士明志科技大學
電子工程研究所
100
In this thesis, two current-mode biquadratic filters and three voltage-mode biquadratc filters by using current-mode active components are proposed. The first proposed current-mode filter uses three second generation current conveyors, two grounded capacitors and two grounded resistors. The second proposed current-mode filter uses three plus-type differential voltage current conveyors, two grounded capacitors and three grounded resistors. The proposed current-mode filters can realize low-pass, band-pass, high-pass, band-reject and all-pass filtering responses, simultaneously, without changing the passive elements. Moreover, the current-mode filters still enjoys (i) employment all grounded passive elements, (ii) no need component-matching conditions, and (iii) low active and passive sensitivities. On the other hand, three voltage-mode biquadratc filters are proposed. The first proposed voltage-mode filters uses one single-output differential difference current conveyor, one dual-output inverting second-generation current conveyor, three resistors and two grounded capacitors. It can simultaneously realize low-pass, band-pass, high-pass and band-reject filtering responses. The second proposed voltage-mode filters uses one single-output differential voltage current conveyor, one dual-output inverting second-generation current conveyor, three resistors and two grounded capacitors. The third proposed voltage-mode filters uses two differential difference current conveyors, three resistors and two grounded capacitors. Each of the second and third proposed voltage-mode filters can realize low-pass, band-pass, high-pass, band-reject and all-pass filtering responses. Moreover, the proposed voltage-mode filters still enjoys (i) employment two grounded capacitors, (ii) no need component-matching conditions, (iii) orthogonal controllability of the quality factor and resonance angular frequency, and (iv) low active and passive sensitivities. Finally, we use HSPICE to prove the accuracy of the circuit with TSMC 0.18µm 1P6M process technology. The results show close agreement between theory and simulation.
43
Hao, Teng-Cheng, and 鄧政豪. "Design of oscillators employing the active current-mode elements." Thesis, 2000. http://ndltd.ncl.edu.tw/handle/84775184107487034605.
Повний текст джерелаАнотація:
碩士中原大學
電機工程學系
88
Six novel sinusoidal oscillators are presented in the paper and we divided the paper into four parts. The first part of the paper is concentrated on the realization of three novel single-resistance-controlled current- / voltage-mode sinusoidal oscillators using dual-output second-generation current conveyors (DO-CCII’s). The current-mode sinusoidal oscillator employing one DO-CCIIpn, one CCII+, two grounded capacitors and three grounded resistors is presented. The proposed circuit offers the following advantageous features: employment of three grounded resistors for ease of adjustment, employment of two grounded capacitors ideal for integration, independent oscillation control through a single grounded resistor and independent frequency control through a single grounded resistor. The two voltage-mode sinusoidal oscillators employing two DO-CCII’s, two grounded capacitors and three grounded resistors are presented. The proposed circuits offer the following advantageous features: employment of three grounded resistors for ease of adjustment, employment of two grounded capacitors ideal for integration, independent oscillation control through a single grounded resistor and independent frequency control through a single grounded resistor. The second part of the paper is concentrated on the realization of novel sinusoidal oscillator employing a single plus-type second-generation current conveyor(CCII+), two grounded capacitors and two resistors. The proposed circuit offers the following advantageous features: employing the minimum active element(one CCII+)and the minimum passive elements (two capacitors and two resistors) and employing only two grounded capacitors which are ideal for integration The third part of the paper is concentrated on the realization of a novel sinusoidal oscillator employing one dual-output second-generation current conveyor (DO-CCII), two grounded capacitors and three resistors. The proposed circuit offers the following advantageous features: employment of only two grounded capacitors, ideal for integration, independent oscillation control through a single grounded resistor, and independent frequency control through a single grounded resistor. The fourth part of the paper is concentrated on the realization of one OTA-C sinusoidal oscillator by using two OTA’s and two grounded capacitor are presented. The proposed circuit offers the following advantageous features: employment of only two grounded capacitors which are ideal for integration, orthogonal control of oscillation condition and oscillation frequency through two separate grounded resistors. Finally, we use PSPICE and Matlab to prove the feasibility and the accuracy of the circuit. The results show that the simulation value agrees well with the simulation value.
44
Feng, An Hsuan, and 馮安萱. "Ocean Current Power System featuring an Active Mooring Concept." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/9657qc.
Повний текст джерела
45
Cheng, Mei-Lung, and 鄭美龍. "Design of multifunction filters using active current-mode elements." Thesis, 1996. http://ndltd.ncl.edu.tw/handle/85266733417534686611.
Повний текст джерела
46
Ruoh-Fei, Chaw, and 趙若飛. "Design of active filters employing the second generation current conveyors, differential voltage current conveyors and voltage or current followers." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/70905788768139095820.
Повний текст джерелаАнотація:
碩士中原大學
電機工程研究所
86
It has been verified that the circuits constructed by active current-mode elements have the advantage of higher signal bandwidths, larger dynamic range, greater linearity, less power dissipation and simpler circuit structure. So, the circuits which are designed by employing the current conveyor and the current feedback amplifier have been received considerable attention recently. In addition, the differential voltage curre-nt conveyor was presented by H. O. Elwan and A. M. Soliman in 1997. This active element is a powerful building block, especially for applica-tion demanding differential or floating inputs like impedance converters and current-mode instrumentation amplifiers.We proposed two filters using the second-generation current conve-yor, which are one multifunction voltage-mode filter with one input and three outputs and one universal current-mode filter with three inputs and one output, respectively.Comparing with the published paper, the proposed circuits offer the following advantageous features: use fewer active and passive components, suit for integration and enjoy low active and passive sensitivities.Moreover, we design a serial voltage-mode or current-mode filters employing the differential voltage current conveyor. We also discuss their characteristics and feasibilities.The last, we proposed a current-mode filter with one input and three outputs using the voltage follower and current follower which are with low tracking errors.The results of experiments and simulations using the IC-AD844 or the Design Center 6.1 are obtained to confirm the theoretical predictions.
47
Chang, Chao-Kuei, and 張昭貴. "The Design of Analog Circuit Using Current-Mode Active Components." Thesis, 2002. http://ndltd.ncl.edu.tw/handle/64985760795378868193.
Повний текст джерелаАнотація:
碩士中原大學
電子工程研究所
90
In recent years, the current-mode active components is popular in scholastic discussion and commercially used. Current-mode active components have the advantages of wider bandwidths, larger dynamic range, lower power-consumption, smaller area and easier to design. The object of this study is the design analog filter circuit using current-feedback amplifier. This thesis divided into two topics. First, several current-feedback amplifiers to carry out the three-inputs and single-output, second-order universal filter and the single-input and multi-outputs second-order universal filter published in the recent years. I study them in order to find out the skills of designing analog circuits. Second, a voltage-mode four-inputs and single-output second-order universa filter is proposed. The proposed circuit employs only one current-feedback amplifier, two capacitors and three resistors. The use of only one active components simples configuration. PSpice simulation and experimental results of the proposed circuit consist with the theoretical results.
48
Fu-Ji, Teng, and 鄧福智. "The Design of Analog Circuits Using Current-Mode Active Components." Thesis, 1998. http://ndltd.ncl.edu.tw/handle/11041254551055526619.
Повний текст джерелаАнотація:
碩士中原大學
電子工程研究所
86
Recently, the current-mode circuits havebeen popular, because of their high bandwidths,large dynamic ranges and simple circuit configurations. The design of analog circuitsusing current-mode active components suchas current conveyors, current feedback amplifiers and operational transconductanceamplifiers is discussed in this thesis. The thesis is consisted of two topics and described as follows : Voltage-mode and current-mode filters : The designs of three-input and single-output voltage-mode universal biquadraticfilter employing second-generation current conveyors and of single-input and two-outputcurrent-mode multifunctional filter employingone current feedback amplifier are proposed. The advantages of these filters are (1) using fewer elements ; (2) low active and passivesensitivities ; (3) no requirements for componentmatching conditions (except the first circuit show in Fig. 3-3) ; and (4) the realizations of different filters from the same configuration. Impedance simulators : It employs operational transconductanceamplifiers. Two circuits which are composed of positive and negative impedance simulators are designed. Therefore, the given value of impedanceis available for the adjustable transconductance gains of operational transconductance amplifiers. The circuits depicted as above could be verifiedby experiments or simulations.
49
Hsieh, Ming-Yuan, and 謝明原. "Design of Quadrature Sinusoidal Oscillators Using Active Current-Mode Elements." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/k79mrb.
Повний текст джерела
50
Liou, Yu-Fan, and 劉與凡. "Modified predictive current control for the active power filter application." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/j7twa3.
Повний текст джерела