Дисертації з теми "Variable frequency drive schemes"
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Schad, Judah, Cameron Nichols, and Katelyn Brinker. "Permanent Magnet Synchronous Motor Variable Frequency Drive System." International Foundation for Telemetering, 2017. http://hdl.handle.net/10150/627008.
Повний текст джерелаPatel, Sagarkumar. "Speed Control of Three-Phase Induction Motor Using Variable Frequency Drive." Thesis, California State University, Long Beach, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10690223.
Повний текст джерелаThere are various methods for speed control of induction motors. This paper specifically describes one of the methods: speed control using variable frequency. The proposed system is a MATLAB simulink model, which is a closed loop model designed to achieve desired speed control of a three-phase induction motor by varying its frequency. The simulink model has four main blocks, namely the inverter, synchronous machine, proportional integral control and current hysteresis control. For accuracy of output results and simplicity, we have used dq to abc transformation block and sin function block. The inverter is comprised of six integrated gate bipolar transistors (IGBTs), which are fired by gate pulses generated by current hysteresis control block. The inverter generates variable frequency and variable voltage output, which is given to motor terminals. The project presents the working principle of variable frequency drive (VFD), its performance, and the use of Pulse Width Modulation (PWM) in a three-phase inverter to control the frequency and thus the speed. The proposed method conformed to performance predictions and delivered the desired outputs.
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 джерелаGibson, Richard Samuel. "Reduction of variable speed drive IGBT switching loss, utilising the IGBT gate drive, without increasing radio frequency radiated emissions." Thesis, University of Newcastle upon Tyne, 2013. http://hdl.handle.net/10443/2427.
Повний текст джерелаVan, Wiltenburg Philip E. "Mitigation of EMI generated by a variable frequency drive controller for an AC induction motor." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1994. http://handle.dtic.mil/100.2/ADA286045.
Повний текст джерелаPan, Jianyu. "Control of Four-Level Hybrid Clamped Converter for Medium-Voltage Variable-Frequency Drives." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1562943204567575.
Повний текст джерелаAchelpohl, Scott Alan. "Analysis of an Existing Coal Fired Power Generation Facility with Recommendations for Efficiency and Production Improvement." OpenSIUC, 2010. https://opensiuc.lib.siu.edu/theses/378.
Повний текст джерелаHalilovic, Amer. "Experimental Transient Behaviour Characterisation of Induction Motor fed by Variable Frequency Drives for Pump Applications." Thesis, KTH, Elektrisk energiomvandling, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-157319.
Повний текст джерелаAnvändningen av frekvensomriktare i centrifugalpumpar har väckt fr ågan om hur en omriktare skall väljas. Igensättande objekt i avloppsvatten kan ge upphov till transienta laster i pumpsystemen. En oförutsedd lastökning kan sätta igen pumpen om frekvensomriktaren inte kan förse motorn tillräckligt med ström för att möta momentbehovet. För att välja en lämplig omriktare har ett empiriskt tillvägag ångssätt valts i en undersökning av tre olika omriktare. Resultat har visat att det är lämpligast att välja en omriktare med högst överbelastningskapacitet, även om under en kort tid. Vektor hastighetskontroll är metoden som ger stabil körning om omriktaren f ått automatiskt ställa in motorparametrarna.
Su, Heyin. "Modeling of Proposed Changes to SIUC Central Heating, Air-Conditioning, and Power Plant Incorporating Variable Frequency Drive (VFD) and High Efficiency Turbine." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/708.
Повний текст джерелаRuckdaschel, James David. "Harmonic Analysis of a Static VAR Compensated Mixed Load System." DigitalCommons@CalPoly, 2009. https://digitalcommons.calpoly.edu/theses/82.
Повний текст джерелаGuner, Berkay. "Design And Construction Of An Educational Pump Bench With Operational Controls." Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12605754/index.pdf.
Повний текст джерелаAlkan, Deniz. "Investigating CVT as a Transmission System Option for Wind Turbines." Thesis, KTH, Energiteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-121187.
Повний текст джерелаKopecký, Jan. "Řídicí obvody kolejového výtahu." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2020. http://www.nusl.cz/ntk/nusl-413058.
Повний текст джерелаRobinson, Kristine. "Internalized Shame as a Moderating Variable for Inhibited Sexual Difficulties in Adult Women Resulting From Childhood Sexual Abuse." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1318.pdf.
Повний текст джерелаTailony, Rauf. "Internal Combustion Engine Cold Test Driveline Modeling, Analysis and Development." University of Toledo / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1564765172535669.
Повний текст джерелаRicciardi, Tiago Rodarte 1986. "Contribuições para a modelagem de cargas para análise estática e dinâmica de sistemas de energia elétrica." [s.n.], 2015. http://repositorio.unicamp.br/jspui/handle/REPOSIP/261201.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
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Resumo: Modelos matemáticos e computacionais precisos dos diversos componentes de um sistema de energia elétrica são importantes para estudos e simulações em um cenário de planejamento e operação da rede elétrica. Dentre os elementos de um sistema de geração, transmissão e distribuição de energia elétrica, as cargas são as que apresentam maiores dificuldades em serem adequadamente representadas. Embora esse tema de pesquisa tenha sido exaustivamente explorado, a modelagem de carga tem recebido renovada atenção do setor produtivo e da academia por uma série de fatores, dentre os quais podemos destacar a proliferação de medidores eletrônicos, o interesse por modelos de novos equipamentos e a necessidade da representação mais fiel do comportamento de diferentes cargas frente a distúrbios no sistema. Esta tese de doutoramento propõe duas contribuições na linha de pesquisa sobre modelagem de carga em sistemas de energia elétrica. A primeira delas trata-se de um método de modelagem de carga baseado em medições e na detecção de distúrbios naturais de tensão. O procedimento proposto emprega medidores eletrônicos simples, que são instalados junto a instalações em sistemas de distribuição com motivo outro que não o de modelagem de carga. A ideia principal é a de utilizar tais medidores para, paralelamente a função que desempenham, fornecer para a concessionária informações sobre modelos de carga, como um subproduto da função principal que desempenham. A segunda contribuição proposta é na linha da modelagem de carga baseada em templates, uma técnica recentemente proposta na literatura para modelagem dinâmica de cargas industriais de grande porte. Nesta tese é proposto um modelo dinâmico simplificado de motores de velocidade variável controlados via conversores eletrônicos (Variable Frequency Drives ¿ VFDs), o qual é baseado em um modelo modificado de um motor de indução. O modelo proposto é adequado ao contexto da estrutura de modelagem de cargas industriais proposta pela técnica de modelagem baseada em templates e pode ser facilmente agregado e analisado em programas de simulação por parte de usuários sem necessidades de alterações do código fonte
Abstract: Accurate mathematical and computational models from various electric power systems components are important in a scenario of power systems studies and simulations for grid planning and operation. Among the elements in the electricity generation, transmission and distribution systems, the loads are probably the most difficult ones to be accordingly represented. Though this research topic has been exhaustively explored, there is a renewed interest in industry and academia for power systems load modeling, due to several reasons, including the proliferation of smart meters, the appearance of non-conventional types of load and the continuing need for even more confident representation of different load response for system disturbances. This Ph.D. thesis proposes two contributions to power systems load modeling research field. The first one deals with a load modeling method based on measurements and the detection of natural voltage disturbances. The proposed scheme uses simple smart meters, installed close to customers with a main goal other than load modeling. The main idea is to use data provided by those meters to, in parallel to the main function performed by this device, provide to the utility information regarding load models, as a byproduct capable to add value to the investment in this meters. The second contribution is in the template based load modeling, a recently methodology proposed for dynamic modeling of large industrial facilities. In this thesis, a simplified Variable Frequency Drive (VFD) dynamic model is proposed, which one is based on a modified induction machine model. The proposed model is suitable to the dynamic load model structure proposed by the template based methodology and can be easily aggregated and analyzed in simulation software by basic users without the need of programming a complex model
Doutorado
Energia Eletrica
Doutor em Engenharia Elétrica
Lokaj, Jakub. "Teslova bezlopatková turbina." Master's thesis, Vysoké učení technické v Brně. Fakulta strojního inženýrství, 2016. http://www.nusl.cz/ntk/nusl-254360.
Повний текст джерелаTzelepis, Vasileios. "Electromechanics of an Ocean Current Turbine." ScholarWorks@UNO, 2015. http://scholarworks.uno.edu/td/2112.
Повний текст джерелаBinoj, Kumar A. C. "Experimental Studies on Acoustic Noise Emitted by Induction Motor Drives Operated with Different Pulse-Width Modulation Schemes." Thesis, 2015. http://etd.iisc.ernet.in/2005/3960.
Повний текст джерелаLU, MAO-LIN, and 呂茂霖. "Energy Saving Performance of Variable Frequency Drive Screw Chiller." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/772vw2.
Повний текст джерела國立臺北科技大學
能源與冷凍空調工程系
107
According to the US Department of Energys survey on the use of electricity in buildings, the most power-consuming part in air-conditioning systems is chiller unit, accounting for 60% of all systems. 99% of typical chiller units are partially loaded. Therefore, the use of high-efficiency inverters will make the energy-saving effect very significant. This paper shows that the Exchange efficiency COP(Coefficient of Performance, COP)value of the spiral-type chiller units driven by frequency conversion in Taiwans climatic conditions are much better than that of the general fixed-frequency chiller units. This paper takes the air conditioning system of the teaching hospital in the eastern region as an example. After the air conditioning system is replaced and integrated, the monitoring system is used to calculate the required air-conditioning tonnage of the building, control the frequency converting host and auxiliary equipment to load and off-load, and record the electricity consumption to do analysis in order to understand the actual energy saving situation after the replacement of air conditioning equipment. When the equipment is used, the COP value can reach more than 5.50 when operating at 40%~60%. Because the on-site cooling water temperature conditions cannot be matched, there is no expected efficiency. However, the efficiency of the operational state is better than the national standard after comparing with the energy efficiency standards of the chiller unit of the Bureau of Energy, Ministry of Economic Affairs. After the completion of the replacement, the electricity consumption in 2015 was saved by 14.22%, the savings in 2016 was 17.78%, and the emission of CO2 was reduced by about 284,539 kg.
Lin, Feng-Ching, and 林峰慶. "Color Reflective Dual-Frequency Cholesteric Liquid Crystal Displays and the Drive Schemes." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/87192384662755142577.
Повний текст джерела中原大學
物理研究所
99
We propose a color reflective dual-frequency (DF) cholesteric liquid crystal display (CLCD) characterized by the short switching time of merely ~ms from the focal conic (FC) texture to the planar (P) state. Because of the existence of the bistable—P and FC—states at zero field, it is not necessary to hold the driving voltage for operation. Three distinct cholesteric pitches are prepared such that the Bragg reflections take place in red, green and blue in order to realize a color pixel. The cholesteric cells can be directly switched from the bright (reflecting) P state to the dark (light-scattering) FC state by a low-frequency voltage pulse and reversibly from the FC to P state by a high-frequency pulse. We present two drive schemes for the passive- and active-matrix DF-CLCDs. Gray levels are achievable by either amplitude tuning or frequency tuning of the applied voltage pulse.
Han, Xu. "Analysis and Simulation of Mechanical Trains Driven by Variable Frequency Drive Systems." Thesis, 2010. http://hdl.handle.net/1969.1/ETD-TAMU-2010-12-8666.
Повний текст джерелаHsu, King-Huei, and 徐金輝. "A Study on Energy Saving Performance of Variable Frequency Drive Centrifugal Chiller." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/g3fktr.
Повний текст джерела國立臺北科技大學
冷凍空調工程系所
94
Centrifugal chiller is the single largest electrical load in central air-conditioning system. Energy efficiency of a chiller is critical to energy saving performance for a building. This thesis presents that the COP of a variable frequency drive (VFD) centrifugal chiller at operating conditions here in Taiwan is far better than a constant speed drive (CSD) chiller. An ARI certified computer program is used to simulate operation of two 350 tons centrifugal chillers, one is VFD and the other one is constant speed. Analyzed results show that COP of a VFD chiller operates between 100% and 40% load is up to 70% higher than that of the CSD chiller if ECWT drops to 20 ℃ from 30 ℃. COP can be further improved by resetting leaving chilled water temperature if relative humidity is not a concern. The conclusion of this thesis may provide some guidelines for those professionals when they make a selection of centrifugal chillers. Then VFD chillers may be more popularly applied in air-conditioning system design as an effective measure to achieve energy saving requirements.
Chen, Pi-Wen, and 陳湢文. "A Study on Energy Saving Performance of Variable Frequency Drive Screw Chiller." Thesis, 2008. http://ndltd.ncl.edu.tw/handle/u99f5j.
Повний текст джерела國立臺北科技大學
能源與冷凍空調工程系碩士班
96
As chiller for central air-conditioning system is the largest power equipment in the project, the crucial importance of energy-saving impact. The performance tests of the VSD mode and slide-valve mode are in accordance with the ARI Standard ARI-550.590. The curve fitting data of the testing results are inputted for DOE-2 energy simulation models of the office, hotel and hospital building types to do energy-saving analysis and comparison. This research showed that the part load efficiency of variable speed drive control mode of flooded screw chiller is 17% to 30 percent better than that of the slide-valve control mode. Under the climate conditions of Taiwan , the energy consumption of variable speed drive control mode of flooded screw chiller is much lower than that of the slide-valve control mode. The simple pay back year of the additional cost of VSD is about 1 year.
Chen, Wei-Xian, and 陳威憲. "High power factor high efficiency variable frequency three-phase external rotor induction motor ceiling fan drive." Thesis, 2012. http://ndltd.ncl.edu.tw/handle/48976575747821253482.
Повний текст джерела國立勤益科技大學
電機工程系
100
The advantages of dc motors are starting easy and speed control convenient, but the dc motors require frequent maintenance because of the presence of commutators and brushes, which make the motor unsuitable for dirty and explosive environments. In this paper, a high- power-factor high-efficiency inverter drive for three-phase outside rotor induction motor of ceiling fan is presented. First, a control board applying dsPIC30F3010 based on voltage-frequency ratio (V/F) to generate PWM signals is established. Second, the power stage using power MOSFETs as power switches and with protection circuit is developed. Third, a power factor correction (PFC) is designed to improve input current waveform and power factor, and a radio frequency (RF) wireless remote device is established for users to control ceiling fan easy. Experimental results confirm the effectiveness of the proposed drive for ceiling fan.
Wei, Yu-Chun, and 魏宇君. "Study of the Position Control of Linear Ultrasonic Motor Using the Variable Frequency and Amplitude Drive." Thesis, 2007. http://ndltd.ncl.edu.tw/handle/05519584281964671578.
Повний текст джерела國立成功大學
工程科學系碩博士班
95
The piezoelectric actuators have been applied popularly for servo systems, such as the Rotary Traveling-Wave LUSM and the standing-wave Linear Ultrasonic Motor (LUSM). The standing-wave LUSM attracts special interest as direct drive type actuator in industry, medical science, consumers, robotics and automotive application. The speed and position of the conventional LUSM can be manipulated by controlling the frequency, the difference of phases and the voltage amplitude of the sinusoidal voltage waveforms. However, the two-phase sinusoid output voltages of the conventional LUSM are unbalanced under the same switching frequency. Therefore, a good dynamic performance of the conventional LUSM is difficult to be obtained due to the unbalanced two-phase voltages. Because the standing-wave LUSM could be supplied a single phase sinusoidal wave, there is an outstanding performance in practical application without the demerit of the unbalanced two-phase voltages. The driving circuit for the standing-wave LUSM combines the two control circuits to regulate the frequency and the amplitude of the driving voltage. The driving circuit is composed of four stages: voltage-controlled oscillator circuit, voltage-controlled gain amplifier circuit, power amplifier and transformer. The hardware of experiment system is implemented with a low-cost digital signal processor based microcontroller and the separate-type linear scale system. The experiment system reduces the size and cost of hardware and measures the relative position coordinate by feedback signals. According to the experiment results, the driving circuit for the standing-wave LUSM gives more flexible control range and more variable control condition than the other driving circuits.
Kai-MingHo and 何鎧名. "Comparison of the Energy Savings with Variable Frequency Drive and Throttling Valve Control for Sea Water Cooling Pumps." Thesis, 2013. http://ndltd.ncl.edu.tw/handle/03719370633950550918.
Повний текст джерела國立成功大學
系統及船舶機電工程學系碩博士班
101
In a ship’s central cooling system, seawater cooling pumps are normally designed to operate for the temperature of in-take seawater at 32°C when the pumps are under full speed to reach the flow nowadays. However, seawater temperatures have ever gone up this high only in limited areas in the seas around the world within certain seasons. Thus, the actual in-take seawater flow rate can be reduced, resulting in a large reduction of the required amount of electrical energy. This thesis investigates energy consumption reduction in seawater cooling pumps using variable frequency drives (VFDs) and throttle valves to supply continuously variable flow rates to a ship’s central cooling system. A pump characteristic curve is determined in this study to calculate the minimum flow rate of seawater cooling pumps for overcoming the friction losses in the pipe and the actual needs of seawater flow is learned by using thermal equilibrium calculation. Then, the seawater flows are substituted into the pump characteristic equation obtained from the simulation in order to calculate the energy consumption for seawater cooling pumps. In addition, the theoretical results obtained from this thesis are validated by an experiment of a small-scale ship cooling system and the energy-saving benefit of an actual voyage for a practical ship is theoretically assessed by applying the developed equations. Hopefully, the results obtained from this study can be used for ship design for future reference.
Kaarthik, R. Sudharshan. "Multilevel Dodecagonal Space Vector Structures and Modulation Schemes with Hybrid Topologies for Variable Speed AC Drives." Thesis, 2015. http://etd.iisc.ernet.in/handle/2005/2765.
Повний текст джерелаJiang, Dong. "Design and Control of High Power Density Motor Drive." 2011. http://trace.tennessee.edu/utk_graddiss/1196.
Повний текст джерелаPark, Sangtak. "Low Voltage Electrostatic Actuation and Displacement Measurement through Resonant Drive Circuit." Thesis, 2011. http://hdl.handle.net/10012/6269.
Повний текст джерелаTrautman, Neal L. "Chilled Water System Modeling & Optimization." Thesis, 2020. http://hdl.handle.net/1805/23572.
Повний текст джерелаThe following thesis looks into modeling a chilled water system equipped with variable speed drives on different piece of equipment and optimization of system setpoints to achieve energy savings. The research was done by collecting data from a case-study and developing a system of component models that could be linked to simulate the overall system operation.
Moreira, Pedro Miguel Dias. "Sistema de controlo e gestão em equipamentos de elevação." Master's thesis, 2019. http://hdl.handle.net/1822/74277.
Повний текст джерелаDesde a revolução industrial do século XVIII que a rentabilidade depende, em grande parte, do volume de matéria produzido, que permite às empresas baixar preços e ser competitivas. Um equipamento vastamente utilizado na indústria mundial para movimentação de cargas, que atuam como agentes importantes numa linha de produção convencional, são as pontes rolantes e seus homólogos (pórticos, etc). Visto que o transporte de materiais é uma operação diária e não rentável, todo o tempo desperdiçado com esta tarefa é algo a evitar. Esta dissertação de mestrado é direcionada à agilização de processos e modernização destas máquinas. As principais áreas de interesse passam pela interatividade entre a máquina e o utilizador, a soma de cargas entre múltiplos diferenciais e a integração de inversores de frequência. Inerente a estes pontos espera-se um aumento da fiabilidade da máquina e alerta para a responsabilidade que o movimento de grandes materiais implica. Este projeto realizou-se na empresa Norcranes - Equipamentos, Lda [1], fabricante nacional de pontes rolantes, sediada no concelho da Trofa.
Since the industrial revolution that took place in the 18th century profit relies significantly on the amount of matter produced which allows companies to low their prices and get competitive. A widely used equipment in world’s industry to load transportation, that plays as a key element on a traditional production line, are cranes and its counterparts (gantries, etc). Since material transportation is a daily task and a non-profitable one, every second spent doing it is something to avoid. This master’s thesis is oriented to the processes streamlining and cranes renewal. The main fields of interest are the Human-Machine interactivity, load sum between multiple hoists and variable frequency drives integration. Inherent to those topics, it’s expected to increase machine reliability and alert about the responsabilty that movement of big dimensions materials involves. This project was developed in Norcranes - Equipamentos, Lda, national manufacturer of cranes, headquartered in Trofa.