Дисертації з теми "Transformer Taps"
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Hogg, Robert Andrew. "An adaptive, microprocessor based transformer differential relay with harmonic restraint and transformer tap changer detection." Thesis, University of Newcastle Upon Tyne, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315575.
Повний текст джерелаKang, Pengju. "On-line condition assessment of power transformer on-load tap-changers : transient vibration analysis using wavelet transform and self organising map." Thesis, Queensland University of Technology, 2000.
Знайти повний текст джерелаFERREIRA, CARLOS APARECIDO. "AN IMPROVED STEADY-STATE MODEL FOR TAP-CHANGING TRANSFORMER." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2011. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=21702@1.
Повний текст джерелаO fenômeno de estabilidade de tensão vem despertando grande interesse acadêmico e das principais empresas de energia elétrica do mundo desde que começou a ser observado em sistemas reais, no final da década de setenta. Sua ocorrência está relacionada ao carregamento excessivo das linhas de transmissão. Modelar transformador com tap variável adequadamente é fundamental em análises de estabilidade de tensão, tanto no que diz respeito às informações fornecidas ao operador referentes às margens de estabilidade de tensão, quanto aos efeitos de ações de controle de tensão. O modelo de transformador com tap variável utilizado mundialmente consiste de uma impedância, obtida através do ensaio em curto-circuito e com tap nominal, em série com um transformador ideal. Esta tese mostra que, em estudos de estabilidade de tensão, o uso desse modelo leva a resultados qualitativamente errados. Para demonstração, utiliza-se um circuito pequeno e os conceitos de máxima potência transmitida, impedância equivalente da carga, e efeito do controle de tensão. Propõe-se um novo modelo coerente com os resultados obtidos em laboratório, com as leis de circuitos elétricos e com a teoria de estabilidade de tensão. Esse modelo pode ser utilizado em qualquer estudo em regime permanente. Através de diversas simulações computacionais, diferenças quantitativas e principalmente qualitativas foram obtidas comparando-se os resultados dos dois modelos.
The voltage stability phenomenon is of interest since it began to be observed in real systems in the late seventies. It happens due to excessive loading of transmission lines. The modeling of tap-changing transformers is fundamental in voltage stability analysis, in terms of the information provided to the operator about voltage stability margins and the effects of voltage control actions. The model for tap-changing transformers currently in widespread use consists of an impedance, measured in a short-circuit test with a nominal tap, in series with an ideal transformer. The use of this model in voltage stability studies leads to qualitatively incorrect results, as shown in this thesis. For demonstration purpose a small circuit and the concepts of maximum load, equivalent load impedance and voltage control effects are used. An improved model that takes into account laboratory results, circuit laws and voltage stability theory is proposed. This model can be used in any steady-state study. It gives results that are not only more accurate than those obtained with the conventional model, but also, as shown in this thesis, qualitatively different.
Gao, Chao. "Voltage control in distribution networks using on-load tap changer transformers." Thesis, University of Bath, 2013. https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.607476.
Повний текст джерелаFu, Le. "Voltage stability monitoring and enhancement in electrical power systems using transformer tap changers." Thesis, Imperial College London, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.506484.
Повний текст джерелаStenhammar, Oscar. "Analysis of factory test data of on-load tap-changers for power transformers." Thesis, Uppsala universitet, Avdelningen för systemteknik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-447236.
Повний текст джерелаManeikis, Andrius. "Distribution On Load Tap Changer Control Using IEC61850 Client/Server Architecture." Thesis, KTH, Skolan för elektro- och systemteknik (EES), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-193673.
Повний текст джерелаDistribuerad generation håller på att förändra transmissionsnätet till decentraliserat system där separata enheter som vindkraftverk eller solpanel skall samexistera och fungera tillsammans för att komplettera varandra och att göra ett omfattande system som helhet så kallade smarta elnät. Det är ytterst viktigt att ha en kontroll förmåga över sådana enheter inte bara på ett fältnivå utan även på systemnivå. För att kunna kommunicera med många enheter och bibehålla interoperabiliten som universell standard är ett måste. En av de grundläggande normer som är relevanta för smarta nät är IEC 61850 - Skydd & Automation, som kommer in i bistånd och möter ovan nämnda utmaningar. Detta projekt använder IEC61850-struktur för att implementera klient/server windows applikation för lindningskopplarens fjärrkontroll. Den föreslagna lösningen och utformade applikationer testas tillsammans med en realtidssimulator där enkelt kraftsystem modelleras för att emulera systemets svar på de givna styrsignalerna i realtid. På detta sätt kan de implementerade programmen prövas och bedömas hur de utföras i verklig miljö. Följaktligen kan användare av klientapplikationen fjärrstyra spänningen på transformatorns sekundärsida och manipulera ställverk som simuleras i modellen.
Baltazar-Lopez, Martin Eduardo. "Applications of TAP-NDE technique to non-contact ultrasonic inspection in tubulars." Diss., Texas A&M University, 2003. http://hdl.handle.net/1969.1/1614.
Повний текст джерелаPieters, Willem Diederick. "Monitoring, protection, and voltage control of parallel power transformers based on IEC 61850-9-2 process bus." Thesis, Cape Peninsula University of Technology, 2019. http://hdl.handle.net/20.500.11838/3067.
Повний текст джерелаThe purpose of an electrical power system is to supply electrical energy to the customers. Power transformers are required to transform the system voltage from generation to transmission and distribution levels. Protection and control systems must ensure that power system high voltage equipment such as transformers operate and deliver save, reliable and secure electricity supply. The aim of the project research work is to develop and implement a strategy, methods and algorithms for monitoring, protection and voltage control of parallel power transformers based on IEC 61850-9-2 process bus standard. NamPower is a power utility in Namibia. The IEC 61850 protocol for electrical substation automation system is used for the protection and control of 5 power transformers operated in parallel in an existing substation system. The IEC 61850-9-2 process bus standard is however not used in regards of Sampled Values (SV). Protection and control devices are connected to a substation communication network, routers and switches using fibre optic linked Ethernet. Inductive Current Transformers (CTs) and Voltage Transformers (VTs) secondary circuits are hardwired to Intelligent Electronic Devices (IEDs) and fibre optic links are not used for this purpose at process level communication. The research focuses on the implementation of the IEC 61850 standard with Merging Units (MUs) and sampled values to improve the existing implemented protection and control system at NamPower. This includes substation communication networks and MUs used for transformer protection, voltage regulator control and cooling fan control. At the present the CTs located at the transformer bushings and switchgear and the VTs located at the switchgear are hardwired to the inputs on protection and control IEDs. The research focuses on issues with the copper wires for voltage and currents signals and how these issues can be eliminated by using the MUs and the SV protocol. The MUs which are considered in this Thesis is to improve the voltage regulator control and the control of the cooling fan motors. The voltage regulator control IED is situated at the tap change motor drive of the On-Load Tap Changer (OLTC). The IED of each transformer is required to regulate the voltage level of the secondary side bus bar it is connected to. All the regulating IEDs are required to communicate with each other and collectively to control the bus bar voltage depending on the switching configuration of the parallel transformers. The control circuit for controlling the cooling fan motors is hardwired. Temperature analogue signal input into a programmable automation controller IED can be used for controlling the transformer cooling fans. A strategy, methods and algorithms for transformer protection, voltage regulator control and cooling fan motor control of parallel power transformers need to be developed and implemented based on IEC 61850-9-2 process bus. Power utilities and distributors can benefit from interpretation of the IEC 61850-9-2 standard and implementing MUs and SV in substations. MUs can be included in the power transformer protection, automation and control systems. A cost reduction in high voltage equipment, substation installation and commissioning costs and better performance of protection and control system are anticipated.
Karimi, Seywan. "Dielectrics calculation of on-load tap-changer VUCL." Thesis, KTH, Hållbar produktionsutveckling (ML), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292536.
Повний текст джерелаDetta är en kandidatexamen i maskinteknik. Avhandlingens huvudämne är den elektriska beräkningen av kranbytarens sköld. Även om det finns många olika typer av lindnings fokuserar denna studie på VUCL modeller. Den teoretiska bakgrunden för avhandlingen är att den nya skölden är lämplig och användbar i alla VUCL-modeller. Det primära ämnet för avhandlingen är att studera det nya sköld skyddar motståndet rutan i mitten av lindningskopplare. För att göra denna studie är Creo Parametric, Comsol och SpaceClaim de program som används.
Chen, Linwei. "Distribution network supports for transmission system reactive power management." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/distribution-network-supports-for-transmission-system-reactive-power-management(abcc8197-fd85-478b-b91a-fd3d0b3220db).html.
Повний текст джерелаLi, Yun. "Voltage balancing on three-phase low voltage feeder." Thesis, University of Manchester, 2015. https://www.research.manchester.ac.uk/portal/en/theses/voltage-balancing-on-threephase-low-voltage-feeder(4320ec9a-f287-4e83-86fd-c8e29e8d49f4).html.
Повний текст джерелаApelfröjd, Senad. "Grid Connection of Permanent Magnet Generator Based Renewable Energy Systems." Doctoral thesis, Uppsala universitet, Elektricitetslära, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-304659.
Повний текст джерелаWind Power
Wave Power
Marine Currnet Power
Korejčík, Michal. "Návrh transformátoru s regulací fáze pro laboratorní výuku." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2012. http://www.nusl.cz/ntk/nusl-219412.
Повний текст джерелаGirbino, Michael James. "Detecting Distribution-Level Voltage Anomalies by Monitoring State Transitions in Voltage Regulation Control Systems." Case Western Reserve University School of Graduate Studies / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=case1550483383962611.
Повний текст джерелаRosa, Filho Raimundo Nonato. "METODOLOGIA PARA REDUÇÃO DE CUSTOS NA MANUTENÇÃO DOS COMUTADORES DE TAP SOB CARGA DOS TRANSFORMADORES DE POTÊNCIA DE EXTRA ALTA TENSÃO DA ELETRONORTE." Universidade Federal do Maranhão, 2005. http://tedebc.ufma.br:8080/jspui/handle/tede/385.
Повний текст джерелаIn this work a methodology for reduction of maintenance cost in the on-load tap changers (OLTC) of extra high voltage is proposed. The methodology is based on the use of Artificial Neural Networks (ANN) for the intelligent processing of input signals of the commutator. The neural nets adequately trained allow to create an information system and dedicated diagnosis of the OLTC. This system can interpret and diagnosis the components through the real time input signals in order to delay the power transformer maintenance intervals, foreseeing when the OLTC is going to maintenance have intervention based on its condition. It has been adopted a multiperceptron ANN architecture in which the input vector has 22 components and the output considers only one component with the status of the OLTC condition in function of its operation time. This output information is used to determine the periods of maintenance of the commutators. It is reported an application of the proposed system considering the on load tap changer of an autotransformer bank of 500/230/13.8 kV, 600MVA of Centrais Elétricas do Norte do Brasil S/A (ELETRONORTE). The results indicate the advantages of the maintenance based on the condition using ANN.
Neste trabalho é proposta uma metodologia para redução de custo de manutenção nos comutadores de tap sob carga (OLTC) dos transformadores de potência de extra alta tensão. A metodologia está baseada na utilização de redes neurais artificiais (RNA) para o processamento inteligente dos sinais de entrada dos comutadores. As redes neurais adequadamente treinadas permitem criar um sistema de informação e diagnóstico dedicado a OLTC que podem interpretar e diagnosticar os componentes através das entradas em tempo real de forma a, postergar os intervalos de manutenção, prevendo quando o OLTC deverá sofrer intervenção de manutenção baseada na condição do OLTC. Foi adotada uma arquitetura de RNA de multiperceptron na qual a entrada considera um vetor com 22 entrada e apenas uma saída com o status da condição do OLTC em função do tempo de operação. Essa informação de saída é utilizada para determinar os períodos de manutenção dos comutadores de tap. É realizada uma aplicação do sistema proposto considerando o comutador de tap sob carga de um banco de autotransformador de 500/230/13.8kV, 600MVA da Centrais Elétricas do Norte do Brasil S/A( ELETRONORTE) e os resultados indicam as vantagens da manutenção baseada na condição usando RNA.
Petersson, Björn. "Design av mikrovågsövergångar." Thesis, Linköping University, Department of Electrical Engineering, 2003. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-1593.
Повний текст джерелаIn this Master thesis, microwave connections between circuit boards are constructed. The primary frequency band is the X-band (8-12 GHz). The purpose of the connections is to enable a more simple and cheaper way of mounting the circuit boards inside a container.
The connections have been designed and evaluated, using different computer programs. A few prototypes have been built and measured.
The main goal of this Master thesis was to design a connection, that would be useful in practice. The connections should be easy to manufacture and have a good performance. They should also have a high tolerance for manufacturing errors.
The main part of this report contains descriptions of different designs. The designs are presented together with simulated and measured results.
The report contains designs based upon coplanar waveguides and a phase shifting technique. The result shows that designs that are using coplanar waveguides are good. The phase shifting technique has some limitations and need to be developed further.
Athanasius, Germane Information Technology & Electrical Engineering Australian Defence Force Academy UNSW. "Robust decentralised output feedback control of interconnected grid system." Awarded by:University of New South Wales - Australian Defence Force Academy, 2008. http://handle.unsw.edu.au/1959.4/39591.
Повний текст джерелаVasconcelos, Fillipe Matos de. "Uma abordagem Lagrangiana na otimização Volt/VAr em redes de distribuição." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/18/18154/tde-06062017-072758/.
Повний текст джерелаThis work proposes a new model and a new approach for solving the Volt / VAr optimization problem in distribution systems. The Volt/VAr optimization consists, basically, to determine the settings of the control variables of switched capacitor banks, on-load tap changer transformers and voltage regulators, in order to satisfy both the load and operational constraints, to a given operational objective. The problem is formulated as a nonlinear programming problem, multiperiod, and with continuous and discrete variables. Nonlinear programming algorithms were used in order to take advantage of the highly sparse matrices built along the solution method. The discrete variables are treated as continuous along the solution method by means of the use of sinusoidal functions that penalize the original objective function while the control variables do not converge to any of the predefined discrete points in its domain. The multiperiod, or dynamic, characteristic of the problem, however, refers to the use of a constraint that relates the settings of the control variables for successive time intervals that limits the control devices switching operations number for a period of 24-hours. The study is based, methodologically, on Primal-Dual Logarithmic Barrier method. To demonstrate the effectiveness of the proposed model and the robustness of this approach, the data were obtained from theoretical literature surveys, and tests were performed on test-systems of 10, 69 and 135 buses, and in a 442 buses located in the Northwest of the United Kingdom. The computational implementation was accomplished in the softwares MATLAB, AIMMS and GAMS, using the IPOPT solver as solution method. The results have shown the approach for solving nonlinear programming problems is effective to appropriate cope with all the variables presented in Volt/VAr optimization problems.
Chakrabarty, Shantanu. "Algorithms for Adjusted Load Flow Solutions using the Complementarity Principle." Thesis, 2016. http://etd.iisc.ac.in/handle/2005/4161.
Повний текст джерелаRahimpour, Hossein. "The practical field measurement challenges of transformer FRA and developing the fundamentals for an on-line approach." Thesis, 2018. http://hdl.handle.net/1959.13/1393103.
Повний текст джерелаOne of the most effective and powerful tools for the diagnosis of poor mechanical integrity of transformer windings is Frequency Response Analysis (FRA). For large transformers within a power network, which are often critical and expensive, FRA adds enormous value in the diagnosis of winding defects. Which can easily result in the catastrophic failure of a transformer. FRA due to its non-invasive nature and relatively fast assessment, has become an essential tool for the monitoring of transformer winding structural integrity. Enabling utilities to maintain and monitor power transformer windings in a cost-effective manner to minimize the likelihood of an unexpected and costly outage. Transformers are only designed to withstand certain levels of mechanical forces which can be surpassed during short circuit events, transport mishaps or loss of clamping pressure; which may result in winding displacement and deformation. Defects can also occur due to transformer aging, through short circuits and over voltages. To date, FRA has been almost exclusively utilized off-line, which requires a transformer to be completely isolated from the network. However, there is a need to move from off-line to on-line measurement due to the growing importance in the development of smart grid systems. In this study, FRA sensitivities have been investigated through case studies, which inform interpretation of FRA for both off-line and on-line measurements. Real scenarios such as conducting measurements on GSU transformers at power stations, autotransformers at substations and measurements on a rectifier transformer at an Aluminium smelter company have been investigated. This thesis proposes a bushing tap signal injection method using high frequency Current Transformers (CT). The developed technique has the potential to be used for on-line monitoring of power transformers. The technique uses a wide-band signal coupled into the transformer winding via a high frequency CT. The response signal is also measured through another higher frequency CT at a corresponding phase bushing. This non-invasive monitoring tool provides a safe means to access an in-service power transformer, which makes it feasible for permanent onsite monitoring of power transformers.
盧育瑞. "Effects of Transformer Tap Changer on Power System Voltage Stability." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/39357161867555272002.
Повний текст джерелаHe, Shang-Ji, and 何上吉. "Optimization of No Voltage Tap Changer Transformer Settings in Power Plants." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/32q3np.
Повний текст джерела國立臺北科技大學
電機工程系所
104
Transformer tap settings of power plant affects reactive power output and plant equipment performance.It is an important issue. Therefore, this thesis references IEEE C57.116 standard and applys power flow analysis to optimal settings of transformer no voltage tap changer.Because transformers tap are no voltage tap changer and can not switch under the voltage condition, they need to do optimal settings after complete evaluation in every online stage. The thesis derives generator voltage and reactive power relationship by using IEEE C57.116 standard, knowing the system voltage, unit transformer impedance and unit transformer tap is an important factor in the impact of the generator reactive power range,and then applys power flow analysis to reactive power output capability of generator for each tap in the normal system voltage range. Unit auxiliary equipment in power plant is necessary and power supply is powered by a generators.To boost the operating efficiency and stability of the equipment, its voltage must also operate within a limited range by tap setting of unit auxiliary transformer. In this thesis, The common four kinds of power supply mode are used and simulated reactive power range in auxiliary equipment voltage limits.The thesis is based on the maximum absorption of reactive power and proposed optimization setting.The results of analysis can realize that tap -2.5% is maximum absorption of reactive power.Finally, adding loss analysis of power of plant as an additional basis for selecting tap, providing a reference for dispatchers.
LEE, CHUN-TA, and 李俊達. "No-voltage Transformer Tap Changer Selection for a Steam Power Plant." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/42137099408517006515.
Повний текст джерела輔仁大學
電機工程學系碩士在職專班
104
The purpose of this paper is to optimize transformer no-voltage tap changer of main generator step up power transformer, start up power transformer, emergency start up power transformer and auxiliary transformer for a steam power plant. This study determines the step up power transformer tap so that the transformer is capable of absorbing or delivering the maximum MVAR output range within the expected system and generator operating voltage variation ranges based on IEEE Std. C57.116. In order to maintain bus voltage of auxiliary transformer loadings within acceptable range because of system voltage deviation and maximum MVAR output range of generator, no-voltage tap changer of auxiliary transformer, start up power transformer and emergency start up power transformer shall be selected through a series of load flow analysis.
"Development of a predictive maintenance program for transformer tap changing equipment." Tulane University, 1998.
Знайти повний текст джерелаacase@tulane.edu
蘇華宗. "Study of connections characteristics on on-load tap changer for transformers." Thesis, 2004. http://ndltd.ncl.edu.tw/handle/29738444432703559850.
Повний текст джерела國立臺灣科技大學
電機工程系
92
In order to ensure voltage quality during operations in the power systems, the On-Load Tap Changer (OLTC) for transformer were used to keep the voltage output stable. The paper discussed and analyzed the potential distribution along the transformer winding by using an impulse voltage applied across the winding. The distribution of impulse voltage on the OLTC at different taps and connections of 69 kV transformer windings has been simulated by using a voltage oscillation analysis program. The simulation results verify the causes of failures at the different connections for OLTCs of 69/ll.95-23.9 kV, 25 MVA transformers in Taipower’s (Taiwan Power Company’s) secondary substations. In addition, the advantages and disadvantages of OLTCs at different connections were discussed. Moreover, improvement strategies for new and existing OLTCs have been provided, that can avoid OLTC failures which may affect the system reliability if the failure is caused due to potential distribution. Indeed, the proposed solutions are practical in the Taipower system and can reduce the failure rates of line-end OLTCs.
Huang, Chiao-Chun, and 黃巧君. "Optimized Setting of No Voltage Tap Changer Transformers Connected to Generators." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/fy8b2j.
Повний текст джерела國立臺北科技大學
電機工程研究所
105
Based on cost considerations, the transformers connected to generators use no voltage tap changers.They are only operated without voltage conditions, so they must be optimized before the on-line phase. This thesis optimizes the setting of no voltage tap changer transformers connected to generators.The optimal goals are the maximum of reactive power absorbtion and the minimum of active power loss. The optimized setting of tap positions can stabilize the system voltage and reduce the active power loss. First, the thesis refers the IEEE C57.116 standard to learn the relationship between the generator voltage and the reactive power, and analysis the range of reactive power output to the system caused by the system voltage, unit transformer impedance and transformer taps. Second, the thesis use the reactive power corresponds to the system voltage and the generator voltage derivatives the currents cross the transformers high side and low side. The result of active power loss is the sum of the copper loss caused by the currents and the iron loss caused by the operation of transformers. In this thesis, the first simulation uses the full load situation to analysis the range of reactive power and active power loss under the conditions of generator voltage, generator excitation limit and system voltage. The second simulation uses actual generation situation to analysis the maximum of reactive power absorbtion and the minimum of active power loss under every tap position by power flow. Finally, the operators can use the result of the simulations in different generation situation to learn the reactive power output and the active power loss under every tap position.
Joannou, Andrew John Lucas. "An investigation of primary tap changing transformers in high frequency isolated converters." Thesis, 2012. http://hdl.handle.net/10210/5363.
Повний текст джерелаIn this thesis, a new isolated DC-DC converter topology is designed which implements a high frequency primary tap changing transformer. This converter is designed to be implemented into renewable energy applications. Renewable or alternative energy resources are becoming more popular by necessity. The voltage generated by renewable energy resources is dependent on the weather conditions, thus the voltage may vary. This novel topology can maintain a regulated DC output voltage for a wide input voltage range by implementing a high frequency primary tap changing transformer. This converter is thus designed to accommodate the voltage changing conditions of renewable energy resources. This converter only requires output bus capacitance for DC bus stiffening. The overall required bus capacitance is therefore effectively reduced compared to other converter topologies. This isolated topology also improves the fundamental power quality. Other power quality components of this new converter are also analysed.
Hung, Wen-Chung, and 洪文忠. "Development of an Auxiliary Controller for Transformers with On-Load-Tap-Changer." Thesis, 2017. http://ndltd.ncl.edu.tw/handle/c4pr2h.
Повний текст джерела國立臺灣科技大學
電機工程系
105
Regarding the case of a power company that has used power transformers with the On-Load-Tap-Changer (OLTC) mechanical device, a mishap attributable to voltage control of power transformers caused system voltage to become too high or too low and resulted in an accident. After reviewing the analysis, it is found that the cause of this kind of accidents is related to an OLTC control system. How to avoid the above accidents and improve the weakness of the current OLTC control system is the purpose of this study. In this study, the research method is to collect the previous representative cases of mishaps involving voltage control of power transformers. After exploring the reasons and in-depth understanding of the OLTC operation control mode, it is proposed that an "auxiliary controller" be added to the current OLTC control system. Using the simple rules of four electrical signals of CTIV monitoring, namely sampling action numbers (C), action time (T), action current (I) and action voltage (V) to correctly monitor the operation of the OLTC, we will be able to improve the weaknesses of the current OLTC control system and avoid accidents related to voltage control. In addition, the design of the "auxiliary controller" has abandoned the current EM circuit, and changed with the application of PLC, PM and MMI interface as the main units, which are already mature in the industry and considered user-friendly. Finally, through laboratory simulation tests and field tests in two substations, it was proved that the "auxiliary controller" can achieve the purpose of enhancing stable power supply and safe operation of the power transformer.
Tsai, Jin-Long, and 蔡進隆. "Influencing of Steel Plants on On-load Tap Change and Voltage Control of Primary Substation Transformer." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/jz66dy.
Повний текст джерела國立虎尾科技大學
電機工程研究所在職專班
99
Operations of electric arc furnace in steel plants cause serious variation of bus voltage amplitude on primary substation, then On-load Tap Changer (OLTC) of main transformer in the substation happens too many switching times. The switching events affect extreme reliability of the transformer. Based on measured data of the transformer by power SCADA system, the thesis applies Back-propagation neural network method to study the effectiveness of Auto Voltage Regulation (AVR) on OLTC and qualities of secondary bus voltage of the transformer. Besides, the under-voltage electronic fault indictor of AVR is improved also. As a result, acting times of OLTC of the transformer can satisfy a proper operating requirement.
Hou, Jun-Kai, and 侯鈞凱. "Measurement and Analysis of Voltage Fluctuation Impacts on On-Load Tap Changer of Substation Transformers." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/45273784878433650914.
Повний текст джерела國立中正大學
電機工程所
98
As the countries all over the world face the demand of economical developments, many large electric loads, such as steel and petrochemical plants, semiconductor parks, and others have been widely operated in the power system network, meanwhile many manufacturers start to increase the productivity by expanding more power-consuming equipment. Among many electric loads, the operations of steel plants play as one of the most important roles since they provide steel materials which are essential to economical developments. Electric arc furnaces (EAFs) are commonly used in steel industries for steel-making; however, the operation of EAFs present violent and random characteristic which may cause considerable power quality problems. One of significant power quality pollution comes from the voltage flicker. In this study, the goal is to investigate the power quality problems that occur in a Taipower Primary substation system, Sinying P/S, where the P/S feeds electric power to several steel-making customers. Recently, due to the operations of these EAF loads, it is observed that serious voltage fluctuations occurred at the bus that connected to the P/S transformers. The on-load tap changers (OLTCs) of the transformers have thus frequently switching on and off, which deteriorate transformers life and also affect the supply power quality. For mitigating such disturbances, it is necessary to estimate if it needs to set up any flicker control devices, such as static var compensators (SVCs). The main studies of this thesis include following tasks: (1) Performing field measurements for observation of the actual power quality problems occurred on Sinying P/S; (2) Review the related standards to assess the voltage flicker index; (3) Investigation of the inter-operation between SVC and OLTC; (4) Providing appropriate improving strategies to deal with voltage flicker or other power quality problems.
Cui, Wei. "Study of transient impulse voltage distribution and evaluation of tap-lead insulation of a power distribution transformer." 1997. http://hdl.handle.net/1993/19396.
Повний текст джерелаTuson, Paul Matthew. "Transmission transformer tap changer optimisation while minimising system losses using security unconstrained Optimal Power Flow (OPF) techniques." Thesis, 2012. http://hdl.handle.net/10539/11632.
Повний текст джерелаLin, Kun-Yeh, and 林昆燁. "Coordination Control of Static Var Compensator and Onload Tap Changer Transformerby Using Fuzzy Logic." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/88834152008028644983.
Повний текст джерела國立中正大學
電機工程研究所
99
In this study, the goal is to investigate the power quality problems that occur in a Taipower’s primary substation system (P/S), where the P/S feeds electric power to several steel-making customers. Recently, due to the operations of these EAF loads, it is observed that serious voltage fluctuations occurred at the bus that connected to the P/S transformers. The on-load tap changers (OLTCs) of the transformers have thus frequently switched on and off, which deteriorate the transformer life and also affect the supply power quality. This study analyzes the power quality impact of severely load variations on the feeder under the area where has several steel industry customers. It uses simulation techniques and accurate equipment models to test the simulation, and assess the effects of installing SVC to support the installation of SVC in the existing area. In order to improve the switching situation of OLTC, this study adopts the fuzzy control for OLTC and SVC coordination. And it explores the relation between the OLTC operation and the voltage flicker to clarify the result of OLTC malfunction. Finally, it assesses the power quality of a primary substation with large arc furnace loads.
Yan-HoWu and 吳彥和. "Design and Implementation of Alarm Equipment for Auxiliary System of On-Load Tap Changer of Transformers." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/33914542361552363341.
Повний текст джерела國立成功大學
電機工程學系碩士在職專班
104
This thesis proposes alarm equipment for auxiliary system of on-load tap changer of transformers. The proposed system is capable of filtering the abnormal signal and delivering the alarming signal. This design is motivated because the occurrence of abnormal operation of on-load tap changer often results in the abnormal increment or decrement of voltage at the secondary side of transformers. Therefore, the thesis is devoted to designing the alarm equipment for auxiliary system of on-load tap changer based on the number of times of signal changes. From the test result, it was found that the method proposed in this thesis along with the developed system come with the functions of noise detection, noise filtering, and system forewarning. The outcome gained from these tests serve as beneficial references for electric power applications.
Chang, Tsang-Bin, and 張倉賓. "THE ANALYSIS OF ON-LOAD TAP-CHANGER TRANSFORMER REGULATING THE DISTRIBUTION SYSTEM VOLTAGE BY USING DIFFERENT REFERENCE VOLTAGE." Thesis, 2003. http://ndltd.ncl.edu.tw/handle/60866907021517531925.
Повний текст джерела大同大學
電機工程研究所
91
Generally the on-load tap-changer transformers of Taiwan Power Company’s conventional power distribution system only detect and gather the low-voltage side single-phase voltage for reference values. Because the unbalance of distribution system will cause the different three phase voltage that will make the on-load tap-changer transformers inappropriate adjustment of the voltage. The thesis is using DSP collocated wavelet transformation filtering the noise, then calculated the positive voltage accurately as the reference voltage of three-phase voltage transformer to avoid the voltage at the end points of the consumer feeder is too high or too low. The thesis adopts Simulink release 13 to simulate a five bus distribution system. The results of simulation are the comparison between the distribution system voltages that the reference voltages of on-load tap-changer transformer is adopted the single phase voltage and the reference voltages of on-load tap-changer transformer is adopted the positive sequence voltage. According to the results of simulation, using the positive sequence voltage as the reference value of the on-load tap-changer transformer can avoid the inappropriate adjustment of the voltage that was used the single phase as the reference value and the lifetime of tap-changer increase because of the less position shift. Therefore using the positive sequence voltage as the reference value of the on-load tap-changer transformer is the better choice.
Chiu, Cheui-Lu, and 邱垂祿. "VLSI Architectures for 2-D Forward and Inverse Discrete Wavelet Transform Using 4-tap Daubechies Filters." Thesis, 2006. http://ndltd.ncl.edu.tw/handle/87912371214070891187.
Повний текст джерела中華大學
電機工程學系碩士班
94
In the field of digital image processing, the JPEG-2000 standard uses the discrete wavelet transform for image compression; hence, the two-dimensional (2-D) forward discrete wavelet transform (FDWT)/ inverse DWT (IDWT) has recently been used as a powerful tool for image coding/decoding systems. 2-D FDWT/IDWT demands massive computations, hence, it requires a parallel and pipelined architecture to implement high-efficiency application-specific integrated circuits (ASIC) or field programmable gate array (FPGA). At the heart of the analysis stage of the system is the FDWT. In the synthesis stage, the IDWT recovers the original image from the coefficients of FDWT. This paper proposes two architectures with computing time for 2-D FDWT and IDWT. The first high-efficiency architecture comprises a transform module, an address generator, and a RAM module. The transform module has uniform and regular structure, simple control flow. The second architecture features parallel and pipelined computation and high throughput, both of the proposed architectures are 100% hardware-utilization and suitable for 2-D digital image processing, such as JPEG-2000. The proposed VLSI architectures are realized with Verilog HDL, synthesized by the Synopsys Design Compiler. Finally, the layouts for those designs are generated with the Synopsys Astro Tools in a 0.18 1P6M CMOS technology.
Παππά, Αγγελική. "Μελέτη σφαλμάτων σε μετασχηματιστές υψηλής τάσης με αυτόματο μεταγωγέα τάσης (TAP changer)". Thesis, 2010. http://nemertes.lis.upatras.gr/jspui/handle/10889/4085.
Повний текст джерелаThe particular project deals with the detailed description of the layout and the operation of the on load tap changer belonging to a transformer of high tension 150kV/21 kV. Furthermore, it describes and analyzes faults that occurs to transformers with on load tap changer using empirical data from DEI S.A. (Public Power Corporation) as well as theoretical analysis and explanation based on bibliography. In particular, there are described the reasons behind these faults , the symptoms that appear to the transformer and the tap changer and the consequences to the transformer and the layout of the tap changer. Moreover, there is reference to the protection systems that the transformer and the tap changer have in order to be protected from the consequences of the faults. Further on, a particular troubleshooting is studied that occurred at the transformer 150 kV/21 kV no1 of the high voltage substation 150 kV/21 kV at the Hellenic Shipyards of Skaramagas and its handling is reported step by step in association with PARALOS TECHNICAL S.A. , the company which was assigned to solve the troubleshooting. Finally, the operation of the on load tap changer is studied in depth through simulation of a high voltage transformer with on load tap changer using MatLab/SimuLink software package. The simulation includes the application of voltage variations at the transformer, occurred to the high voltage network in the case of orderly or disorderly operation of the voltage regulator, as the faulty operation of the voltage regulator was the reason behind the troubleshooting of the transformer of the substation of 150 kV/ 21 kV at the Hellenic Shipyards of Skaramagas.
Yesuratnam, G. "Development Of Algorithms For Security Oriented Power System Operation." Thesis, 2007. https://etd.iisc.ac.in/handle/2005/573.
Повний текст джерелаYesuratnam, G. "Development Of Algorithms For Security Oriented Power System Operation." Thesis, 2007. http://hdl.handle.net/2005/573.
Повний текст джерела