Relevant bibliographies by topics / Switching transient overvoltages

Academic literature on the topic 'Switching transient overvoltages'

Author: Grafiati
Published: 10 December 2022
Last updated: 19 February 2023

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Journal articles on the topic "Switching transient overvoltages"

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Keitoue, Samir, Ivan Murat, Božidar Filipović-Grčić, Alan Župan, Ivana Damjanović, and Ivica Pavić. "Lightning caused overvoltages on power transformers recorded by on-line transient overvoltage monitoring system." Journal of Energy - Energija 67, no. 2 (June 2, 2022): 44–53. http://dx.doi.org/10.37798/201867279.

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Transient overvoltages generated by lightning strikes or switching operations represent a significant risk to bushings and windings of power transformers. They cause stress on the insulation system and can, over time, cause dielectric failure and damage to power transformers. Many transformer failures are reported as dielectric failures and they are not necessarily linked to any particular event when they occur but may be the result of prior damage from transient overvoltage events. Lightning and switching overvoltage waveforms appearing at transformer terminals in real operating conditions may significantly differ from standard impulse voltage waveforms used during laboratory testing. The number and amplitudes of overvoltages which stress the insulation depend on various parameters such as the lightning strike density in the considered area, since it determines how often the transformer is stressed by lightning overvoltages. Since the overvoltage amplitudes at transformer terminals are usually unknown, an on-line overvoltage transient recorder can be used with the ability to sample, analyse and store transients in real-time. In this paper, an on-line transient overvoltage monitoring system (TOMS) for power transformers is presented that is capable to continuously record in real-time various kinds of transient overvoltages such as lightning or switching overvoltages. Special attention is paid to lightning caused transient overvoltages recorded at the terminals of 150 MVA power transformer. Recorded waveforms originating from lightning strikes to overhead lines are correlated with data from the lightning location system (LLS) and supervisory control and data acquisition (SCADA) system. Collected data about overvoltage stresses can be used as the basis for the assessment of the transformer insulation condition, estimation of health index and for analysis of various kinds of events such as faults or equipment failures.
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Furgał, Jakub, Maciej Kuniewski, and Piotr Pająk. "Analysis of Internal Overvoltages in Transformer Windings during Transients in Electrical Networks." Energies 13, no. 10 (May 22, 2020): 2644. http://dx.doi.org/10.3390/en13102644.

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Due to the increasing requirements for the reliability of electrical power supply and associated apparatus, it is necessary to provide a detailed analysis of the overvoltage risk of power transformer insulation systems and equipment connected to their terminals. Exposure of transformer windings to overvoltages is the result of the propagation condition of electromagnetic waves in electrical networks and transformer windings. An analysis of transformer winding responses to transients in power systems is of particular importance, especially when protection against surges by typical overvoltage protection systems is applied. The analysis of internal overvoltages in transformers during a typical transient related to switching operations and selected failures is of great importance, particularly to assess the overvoltage exposure of insulation systems in operating conditions. The random nature of overvoltage phenomena in electrical networks implies the usage of computer simulations for the analysis of overvoltage exposures of electrical devices in operation. This article presents the analysis of the impact of transient phenomena in a model of a medium-voltage electrical network during switching operations and ground faults on overvoltages in the internal insulation systems of transformer windings. The basis of the analysis is simulations of overvoltages in the windings, made in the Electromagnetic Transients Program/Alternative Transients Program (EMTP/ATP) using a model with lumped parameters of transformer windings. The analysis covers the impact of the cable line length and the ground fault resistance value on internal overvoltage distributions.
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Pannila, Earl A. R. L., and Mahesh Edirisinghe. "Signatures of Transient Overvoltages in Low Voltage Power Systems in Tea Factories and Their Implications on Insulation Deterioration and Allied Power Quality Issues." Journal of Electrical and Computer Engineering 2021 (November 19, 2021): 1–12. http://dx.doi.org/10.1155/2021/2623965.

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Electrical equipment and supply cables demand a better quality of supply, with the recent advancements in integrated sensitive solid-state controls. Divergently, proliferated heavy inductive motors and some performance additions based on power electronics have introduced power quality issues to the network. Thus, this study mainly investigates the impact of switching transients generated by electromechanical machines in industrial power systems on insulation deterioration while taking transient overvoltages due to capacitor bank switching also to support. Transients with a high rate of rise are likely to catalyze the degradation of the insulation quality and break down the insulating material through ionization. These steeply passing overvoltage stresses let partial discharges ensue, which can attack the insulation over long service. To unveil this danger, 314 common-mode transient waveforms were measured in the electrical machines of five tea factories in Sri Lanka, in a 50 ms measurement window, taken in 55 measuring attempts. Most of the transients observed are in the form of a damped oscillatory waveform tailed by fast exponential collapse. That correlates to insulation degradation having a very steep rise as 30.04 V/ns, the highest at the withering section. When machines are heavily loaded, situations tend to generate transients with high amplitudes. There were transient bursts that spread as 426.3 ms, while 14 ns fast rise times were recorded from withering motors. Unlike electrical resonance and power-frequency overvoltages, electromagnetic switching transients last even less than 100 ms. To underline this, an analysis of the frequency domain of transients was also presented, which proves high density of high-frequency components reaching 107 kHz range. Accepting the fact that frequency and amplitude are always under the influences of innumerable dynamics, the observational evidence of the study endorses that electrical stress built by the transient nature of the factories reduces the life expectancy of electrical insulation.
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Leman, Jon T., and Robert G. Olsen. "Bulk FDTD Simulation of Distributed Corona Effects and Overvoltage Profiles for HSIL Transmission Line Design." Energies 13, no. 10 (May 14, 2020): 2474. http://dx.doi.org/10.3390/en13102474.

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Power system load growth and transmission corridor constraints are driving industry activity in the area of high surge impedance loading (HSIL). Examples include compact structure design and uprating existing transmission lines. Recent research relating electric field uniformity to transmission line capacity and critical flashover voltage underscored the need for better overvoltage data to quantify insulation margins for HSIL design. To that end, this work extends the finite difference time domain (FDTD) method with distributed corona losses to transmission lines with bundled conductors. The model was adapted for practical use in high-volume statistical transient simulation and applied to an example 500 kV line. Transients included line energization and trapped charge reclosing. Overvoltage profiles and statistical distributions were generated from 9500 simulations obtained by random breaker close timing and variation in line length and altitude. Distributed corona losses reduced 98th percentile line-to-ground switching overvoltages by 4%–14% of nominal. The estimated line-to-ground switching surge flashover probability was 54%–80% lower with corona loss. Corona had less impact on line-to-line overvoltages, but the effects were still notable. Results highlight the importance of considering detailed overvoltage profiles and accounting for corona loss attenuation when seeking to carefully quantify insulation design margins.
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Girgis, A. A., C. M. Fallon, J. C. P. Rubino, and R. C. Catoe. "Harmonics and transient overvoltages due to capacitor switching." IEEE Transactions on Industry Applications 29, no. 6 (1993): 1184–88. http://dx.doi.org/10.1109/28.259731.

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Sadeghkhani, Iman, Abbas Ketabi, and Rene Feuillet. "The Study of Switching Overvoltages under Power System Restoration Scenario Using Extended Delta-Bar-Delta Algorithm." International Journal of Emerging Electric Power Systems 14, no. 3 (June 19, 2013): 219–30. http://dx.doi.org/10.1515/ijeeps-2012-0003.

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Abstract This paper presents an intelligent approach to evaluate switching overvoltages during power equipment energization. Switching action is one of the most important issues in power system restoration schemes. This action may lead to overvoltages that can damage some equipment and delay ‎power system restoration. In this work, transient overvoltages caused by power equipment energization are analyzed and estimated using artificial neural network (ANN)-based approach. Three learning algorithms, delta-bar-delta (DBD), extended delta-bar-delta (EDBD), and directed random search (DRS), were used to train the ANNs. In the cases of transformer and shunt reactor energization, ANNs are trained with the worst case scenario of switching angle and remanent flux which reduce the number of required simulations for training ANN. Also, for achieving good generalization capability for developed ANN, equivalent parameters of the network are used as ANN inputs. The simulated results for a partial of 39-bus New England test system, ‎show that the proposed technique can estimate the peak values and ‎duration of switching overvoltages with good accuracy and EDBD algorithm presents best performance.
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Schwarz, K. K. "Transient switching overvoltages and compatibility of rotating machine insulation." Power Engineering Journal 1, no. 1 (1987): 43. http://dx.doi.org/10.1049/pe:19870008.

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Hanus, Oleksii, and Kostiantyn Starkov. "STUDY OF THE NATURE OF OVERVOLTAGES IN THE ELECTRICAL NETWORK ARISING FROM VOLTAGE TRANSFORMERS." Bulletin of the National Technical University "KhPI". Series: Energy: Reliability and Energy Efficiency, no. 1 (2) (July 2, 2021): 28–36. http://dx.doi.org/10.20998/2224-0349.2021.01.05.

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A non-linear dynamic mathematical model of voltage transformer has been considered and overvoltages arising on the elements of voltage transformer equivalent circuit during transient processes have been investigated. The influence of voltage transformer secondary circuit capacitance on overvoltage multiplicity in the primary circuits and the duration of transients has been determined. The advantages of approximation of nonlinearity of voltage transformers by hyperbolic sine are used. Mathematical expressions determining the nature of changes in the forced and free components of the transient process in an electrical network with a voltage transformer have been obtained. It is shown that with the increase of the electric network capacitance the duration of the transition process damping increases and the frequency of the forced oscillations and the level of overvoltage decrease. It is proved that even small, in comparison with the primary nominal sinusoidal voltage, aperiodic components of the voltage transient process can lead to significant overvoltages during voltage transformer outages. It has been substantiated that both the secondary resistance and the switching torque influence the overvoltage multiplicity arising in the primary winding of voltage transformers. It is shown that the closed secondary winding worsens the disconnection process of non-linear inductance of voltage transformers. The values to which overvoltages increase in this case are determined. According to the results of calculations it is determined that with open secondary winding of voltage transformers the duration of transient process significantly increases. It has been found that the decrease of frequency of forced oscillations, which occurs in this case, is accompanied by an increase of currents in the primary winding of the voltage transformer, which is dangerous in terms of thermal stability of the winding insulation. It is shown, that closing the secondary winding of voltage transformers leads to significant reduction of transient damping time. It is suggested that this algorithm can be used to provide a rapid breakdown (suppression) of ferroresonant processes. The effectiveness of such a measure of stopping of ferroresonance processes as short-term shunting of secondary winding of voltage transformers has been investigated. The correlation of parameters of electric networks (capacity of busbar sections, nonlinearity of characteristics of voltage transformers, disconnection torque, etc.) at which ferroresonance process may occur and consideration of which may allow, in terms of prevention of ferroresonance processes, to identify substations (electric networks) that require more detailed research has been determined. The results of analytical studies were tested in the electric networks of JSC "Kharkivoblenergo" and used in the electricity distribution system for the selection of specific voltage transformers for certain configurations of electrical networks.
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Barzkar, Ashkan, and Mona Ghassemi. "Precise Evaluation of Repetitive Transient Overvoltages in Motor Windings in Wide-Bandgap Drive Systems." Vehicles 4, no. 3 (July 19, 2022): 697–726. http://dx.doi.org/10.3390/vehicles4030040.

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The increasing interest in employing wide-bandgap (WBG) drive systems has brought about very high power, high-frequency inverters enjoying switching frequencies up to hundreds of kilohertz. However, voltage surges with steep fronts, caused by turning semiconductor switches on/off in inverters, travel through the cable and are reflected at interfaces due to impedance mismatches, giving rise to overvoltages at motor terminals and in motor windings. The phenomena typically associated with these repetitive overvoltages are partial discharges and heating in the insulation system, both of which contribute to insulation system degradation and may lead to premature failures. In this article, taking the mentioned challenges into account, the repetitive transient overvoltage phenomenon in WBG drive systems is evaluated at motor terminals and in motor windings by implementing a precise multiconductor transmission line (MCTL) model in the time domain considering skin and proximity effects. In this regard, first, a finite element method (FEM) analysis is conducted in COMSOL Multiphysics to calculate parasitic elements of the motor; next, the vector fitting approach is employed to properly account for the frequency dependency of calculated elements, and, finally, the model is developed in EMTP-RV to assess the transient overvoltages at motor terminals and in motor windings. As shown, the harshest situation occurs in turns closer to motor terminals and/or turns closer to the neutral point depending on whether the neutral point is grounded or floating, how different phases are connected, and how motor phases are excited by pulse width modulation (PWM) voltages.
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Kaczmarek, Michał, and Dariusz Brodecki. "Transformation of Transient Overvoltages by Inductive Voltage Transformers." Sensors 21, no. 12 (June 17, 2021): 4167. http://dx.doi.org/10.3390/s21124167.

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Overvoltage transients occur after any type of switching activity in a power network, such as breaker operation, fault occurrence/clearance and rapid load change. This distortion of voltage is transformed to the secondary circuit of a voltage transformer. The maximum values of such impulses may many times exceed the rated value of its secondary voltage. This can lead to malfunction of measuring or protection devices connected to the secondary circuit of a voltage transformer and even their damage. The paper presents the application of determined values of ratio error at harmonics of the inductive voltage of the transformer to predict the value of transformed slow-front transient overvoltage to their secondary circuits. This will help to prevent malfunction of measuring or protection devices connected to the secondary side of the voltage transformer and increase their safety of operation. The inductive voltage transformer equivalent circuit for transformation of higher frequency components of distorted voltage must be extended with internal capacitances of windings. This is caused by the fact that the resonance phenomenon of the slow-front transient overvoltage results from leakage inductance and capacitance of primary winding, not from the magnetic core. Therefore, this behaviour is independent from the value of the applied voltage.
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Dissertations / Theses on the topic "Switching transient overvoltages"

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Ramli, Mohd Shamir. "Investigation of circuit breaker switching transients for shunt reactors and shunt capacitors." Thesis, Queensland University of Technology, 2008. https://eprints.qut.edu.au/17822/1/Mohd_Shamir_Ramli_Thesis.pdf.

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Switching of shunt reactors and capacitor banks is known to cause a very high rate of rise of transient recovery voltage across the circuit breaker contacts. With improvements in circuit breaker technology, modern SF6 puffer circuits have been designed with less interrupter per pole than previous generations of SF6 circuit breakers. This has caused modern circuit breakers to operate with higher voltage stress in the dielectric recovery region after current interruption. Catastrophic failures of modern SF6 circuit breakers have been reported during shunt reactor and capacitor bank de-energisation. In those cases, evidence of cumulative re-strikes has been found to be the main cause of interrupter failure. Monitoring of voltage waveforms during switching would provide information about the magnitude and frequency of small re-ignitions and re-strikes. However, measuring waveforms at a moderately high frequency require plant outages to connect equipment. In recent years, there have been increasing interests in using RF measurements in condition monitoring of switchgear. The RF measurement technique used for measuring circuit breaker inter-pole switching time during capacitor bank closing is of particular interest. In this thesis, research has been carried out to investigate switching transients produced during circuit breaker switching capacitor banks and shunt reactors using a non-intrusive measurement technique. The proposed technique measures the high frequency and low frequency voltage waveforms during switching operations without the need of an outage. The principles of this measurement technique are discussed and field measurements were carried out at shunt rector and capacitor bank installation in two 275 kV air insulated substations. Results of the measurements are presented and discussed in this thesis. The proposed technique shows that it is relatively easy to monitor circuit breaker switching transients and useful information on switching instances can be extracted from the measured waveforms. Further research works are discussed to realise the full potential of the measuring technique.
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Ramli, Mohd Shamir. "Investigation of circuit breaker switching transients for shunt reactors and shunt capacitors." Queensland University of Technology, 2008. http://eprints.qut.edu.au/17822/.

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Switching of shunt reactors and capacitor banks is known to cause a very high rate of rise of transient recovery voltage across the circuit breaker contacts. With improvements in circuit breaker technology, modern SF6 puffer circuits have been designed with less interrupter per pole than previous generations of SF6 circuit breakers. This has caused modern circuit breakers to operate with higher voltage stress in the dielectric recovery region after current interruption. Catastrophic failures of modern SF6 circuit breakers have been reported during shunt reactor and capacitor bank de-energisation. In those cases, evidence of cumulative re-strikes has been found to be the main cause of interrupter failure. Monitoring of voltage waveforms during switching would provide information about the magnitude and frequency of small re-ignitions and re-strikes. However, measuring waveforms at a moderately high frequency require plant outages to connect equipment. In recent years, there have been increasing interests in using RF measurements in condition monitoring of switchgear. The RF measurement technique used for measuring circuit breaker inter-pole switching time during capacitor bank closing is of particular interest. In this thesis, research has been carried out to investigate switching transients produced during circuit breaker switching capacitor banks and shunt reactors using a non-intrusive measurement technique. The proposed technique measures the high frequency and low frequency voltage waveforms during switching operations without the need of an outage. The principles of this measurement technique are discussed and field measurements were carried out at shunt rector and capacitor bank installation in two 275 kV air insulated substations. Results of the measurements are presented and discussed in this thesis. The proposed technique shows that it is relatively easy to monitor circuit breaker switching transients and useful information on switching instances can be extracted from the measured waveforms. Further research works are discussed to realise the full potential of the measuring technique.
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Felicetti, Roberto. "Voltage Transients in the Field Winding of Salient Pole Wound Synchronous Machines : Implications from fast switching power electronics." Licentiate thesis, Uppsala universitet, Elektricitetslära, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-434652.

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Wound Field Synchronous Generators provide more than 95% of the electricity need worldwide. Their primacy in electricity production is due to ease of voltage regulation, performed by simply adjusting the direct current intensity in their rotor winding. Nevertheless, the rapid progress of power electronics devices enables new possibilities for alternating current add-ins in a more than a century long DC dominated technology. Damping the rotor oscillations with less energy loss than before, reducing the wear of the bearings by actively compensating for the mechanic unbalance of the rotating parts, speeding up the generator with no need for additional means, these are just few of the new applications which imply partial or total alternated current supplying of the rotor winding. This thesis explores what happens in a winding traditionally designed for the direct current supply when an alternated current is injected into it by an inverter. The research focuses on wound field salient pole synchronous machines and investigates the changes in the field winding parameters under AC conditions. Particular attention is dedicated to the potentially harmful voltage surges and voltage gradients triggered by voltage-edges with large slew rate. For this study a wide frequency band simplified electromagnetic model of the field winding has been carried out, experimentally determined and validated. Within the specific application of the fast field current control, the research provides some references for the design of the rotor magnetic circuit and of the field winding. Finally the coordination between the power electronics and the field winding properties is addressed, when the current control is done by means of a long cable or busbars, in order to prevent or reduce the ringing.
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Gregory, Raquel Cristina Filiagi. "Análise computacional do desempenho de estratégia para o religamento controlado de linhas de transmissão." Universidade Federal de Uberlândia, 2016. https://repositorio.ufu.br/handle/123456789/17617.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico
A busca por soluções mitigatórias, no que tange aos efeitos das sobretensões transitórias atreladas às manobras de energizações e religamentos das linhas de transmissão, contemplam um tema desafiador e com fortes impactos sobre a coordenação de isolamento dos sistemas elétricos. Muito embora o reconhecimento de propostas clássicas e comerciais para a atenuação destes fenômenos, outras possibilidades, certamente, ainda são meritórias de destaque e investigações. Neste contexto, a presente dissertação encontra-se alicerçada na exposição dos fundamentos físicos e matemáticos de uma estratégia baseada em chaveamentos controlados, cujos instantes para o religamento da linha são pré-programados. A avaliação computacional da eficácia da metodologia é realizada utilizando o simulador ATP, no qual são efetuados estudos em um sistema elétrico típico submetido à curtos-circuitos sucedidos por desligamentos e subsequentes religamentos, sob a ação da tecnologia aqui focada e na ausência da mesma.
The search for mitigation solutions, with respect to the effects of overvoltages linked to the energization and reclosing maneuvers of transmission lines include a challenging subject with strong impact on the insulation coordination of electrical systems. Although the recognition of classical and commercial proposals to mitigate these phenomena, other possibilities are certainly still worthwhile highlighting and investigations. In this context, the present work is grounded in the exposure of the physical and mathematical foundations of a strategy based on controlled switchings, whose moments to the line reclosing are pre-programmed. The computational evaluation of the effectiveness of the methodology is made using the ATP simulator, which are studies in a typical electrical system subjected to the action of short-circuits fallowed by shutdowns and subsequent reclosing, under the action of technology here focused and lack thereof.
Dissertação (Mestrado)
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Ezzeddine, Kassem, and Robert Oskarsson. "Analys av kondensatorbatteriers tillkopplingsfenomen : Undersökning av de kopplingsfenomen som uppstår vid tillkoppling av kondensatorbatterier och deras påverkan på närliggande komponenter." Thesis, KTH, Data- och elektroteknik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-208948.

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Många elektriska apparater är i behov av reaktiv effekt för att kunna fungera. Transport av reaktiv effekt tar onödig plats av den tillgängliga kapaciteten i elnätet, därför används kondensatorbatterier nära slutanvändaren för att generera reaktiv effekt. Därmed genereras och förbrukas den reaktiva effekten i en avskild del av nätet. Tillkoppling av kondensatorbatterier ger upphov till transienter som kan skada andra närliggande komponenter. Utifrån det verkliga ställverket Stallbacka i Trollhättan har denna rapport analyserat de transienter som uppstår efter tillkoppling av ett kondensatorbatteri inom mellanspänningsområdet. Analysen har innefattat hur stora transienterna blir efter olika förutsättningar och scenarier. Resultatet visade att transienterna i detta fall aldrig nådde upp till några allvarliga nivåer, och därmed klarade komponenterna sig med god marginal. Huruvida transienterna påverkar elkvaliteten är oklart, då det inte finns några definierade krav. Slutligen skulle ett beräkningsverktyg för förutspådda transienter tas fram. Beräkningsverktyget blev aldrig fullständigt på grund av den ohanterliga lösningen som erhölls.
Many electrical devices need reactive power to operate. Transmission of reactive power occupies a proportion of the available capacity in the power system and therefore capacitor banks are used near to the end user to generate reactive power. Thus, the reactive effect is generated and consumed in a separate part of the power system. Capacitor banks switching causes transients which may damage the surrounding components. Based on the real substation Stallbacka in Trollhättan, this study has analysed capacitor banks switching transients within the medium voltage level. The analysis has covered the size of these transients according to different conditions and scenarios. The result showed that the transients in this case never reached serious levels, thus there was no impact on the components. It is not clear whether the transients affect the power quality because there are no defined limits.  A calculation tool to the predicted transients was supposed to be created in the process. This calculation tool was never completed due to the unmanageable solution that was obtained.
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Khandelwal, Sulabh. "Artificial Neural Networks Approach For Estimation Of Line Energization Peak Transient Overvoltages During Restoration." Thesis, 2005. http://etd.iisc.ernet.in/handle/2005/1433.

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(9826433), Rodney Peters. "Transient overvoltages in mine power systems." Thesis, 1998. https://figshare.com/articles/thesis/Transient_overvoltages_in_mine_power_systems/20341575.

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 This thesis investigates the nature and magnitude of switching transient overvoltages that can be expected in inductively grounded underground coal mines. Computer models of power system equipment have been developed to analyse single-phase fault isolations; motor starts (including prestriking) and motor turn offs. The computer models that were developed have been validated against field recordings. The "Alternative Transients Program" (ATP) software was used to conduct the computer simulation studies. 

The underground substations used in Central Queensland coal mines are grounded through a Neutral Earthing Reactor (NER). The primary purpose of a NER is to limit earth fault currents. However, when a single -phase -to -ground fault occurs, energy is stored in the NER. Consequent to the isolation of such a fault, the energy stored in the NER is released. The release of this energy manifests itself as a transient overvoltage. This thesis investigates the effect of the rating of the NER and the value of the electric current at the instant of earth fault isolation on transient overvoltages. 

Two alternate earthing schemes were investigated in an attempt to reduce the severity of the transient overvoltages consequent to the isolation of earth faults. The first alternative that was investigated was the addition of a Resistor -Capacitor Snubber in parallel with a NER. Computer simulations indicate that the proper choice of Snubber parameters is very effective in reducing transient overvoltages following the isolation of earth faults. Consequently, a decision was made to manufacture a R -C Snubber and conduct field tests on the same. A summary of the field tests results has been included in the thesis. 

The other alternate grounding scheme that was investigated was the substitution of a Neutral Earthing Reactor with a Neutral Earthing Resistor. Computer simulations indicate that transient overvoltages following the isolation of earth faults are virtually eliminated if a Neutral Earthing Resistor is used. 

Consequent to this research work, the use of R -C Snubbers has become a recommended practice at various coal mine sites in Australia which use NER grounded, container type substations. The R -C Snubber is the preferred alternative at such installations as it is very compact and also eliminates the heating/reliability problems associated with resistance grounding. 

Vacuum contactors are used throughout the Central Queensland mines to frequently turn motors on and off. One of the most significant characteristics of vacuum contactors is their ability to interrupt high frequency currents. The consequence of this is that a considerable number of high frequency prestriking transients can be generated whenever a motor is turned on. These high frequency transients can lead to the premature aging of insulation. This thesis presents a computer model that was developed to simulate prestriking transients using the TACS (Transient Analysis of Control Systems) programming feature of the ATP software. Further investigation of prestriking transients was considered to be beyond the scope of the present research project. However, the unique TACS based prestriking model of a vacuum contactor that has been developed will be a useful tool for conducting further research.   

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"Investigating Transient Overvoltage Produced by Switching Action on Long Transmission Lines and Its Effect on Substations." Master's thesis, 2018. http://hdl.handle.net/2286/R.I.51756.

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abstract: Switching surges are a common type of phenomenon that occur on any sort of power system network. These are more pronounced on long transmission lines and in high voltage substations. The problem with switching surges is encountered when a lot of power is transmitted across a transmission line/network, typically from a concentrated generation node to a concentrated load. The problem becomes significantly worse when the transmission line is long and when the voltage levels are high, typically above 400 kV. These overvoltage transients occur following any type of switching action such as breaker operation, fault occurrence/clearance and energization, and they pose a very real danger to weakly interconnected systems. At EHV levels, the insulation coordination of such lines is mainly dictated by the peak level of switching surges, the most dangerous of which include three phase line energization and single-phase reclosing. Switching surges can depend on a number of independent and inter-dependent factors like voltage level, line length, tower construction, location along the line, and presence of other equipment like shunt/series reactors and capacitors. This project discusses the approaches taken and methods applied to observe and tackle the problems associated with switching surges on a long transmission line. A detailed discussion pertaining to different aspects of switching surges and their effects is presented with results from various studies published in IEEE journals and conference papers. Then a series of simulations are presented to determine an arrangement of substation equipment with respect to incoming transmission lines; that correspond to the lowest surge levels at that substation.
Dissertation/Thesis
Masters Thesis Electrical Engineering 2018
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Conference papers on the topic "Switching transient overvoltages"

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Azevedo, L. C., I. P. Faria, and G. P. Lopes. "Switching transient overvoltages analysis on 500 kV transmission line." In 2018 Simposio Brasileiro de Sistemas Eletricos (SBSE) [VII Brazilian Electrical Systems Symposium (SBSE)]. IEEE, 2018. http://dx.doi.org/10.1109/sbse.2018.8395818.

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Liao, Yanqun, Tingxi Sun, Dai Cao, Xuezhong Liu, Hao Liu, and Man Xu. "Numerical analysis of transient overvoltages from sequential switching of 220 kV tunnel cables." In 2017 4th International Conference on Electric Power Equipment - Switching Technology (ICEPE-ST). IEEE, 2017. http://dx.doi.org/10.1109/icepe-st.2017.8189007.

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Yang, Xiao, Fang Chun-en, Chen Chuanjiang, Li Wei, Zhang Bi-de, and Ren Xiao. "Study on high-frequency transient overvoltages protection in offshore wind farms based on RC snubbers." In 2017 4th International Conference on Electric Power Equipment - Switching Technology (ICEPE-ST). IEEE, 2017. http://dx.doi.org/10.1109/icepe-st.2017.8188994.

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Sabin, D. D., T. E. Grebe, D. L. Brooks, and A. Sundaram. "Rules-based algorithm for detecting transient overvoltages due to capacitor switching and statistical analysis of capacitor switching in distribution systems." In 1999 IEEE Transmission and Distribution Conference (Cat. No. 99CH36333). IEEE, 1999. http://dx.doi.org/10.1109/tdc.1999.756124.

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Ku, Bih-Yuan, and Yuan Tai Hsu. "AC Electrified Rail Train Converter Switching Overvoltage Transients Study." In 2009 Joint Rail Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/jrc2009-63030.

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Abstract:
In this paper we present the result of a case study on the switching overvoltage transients of ac electrified railroad trains equipped with switch-type rectifiers in Taiwan Railway Administration (TRA). It was found that new generation of switch-type converters could result in significant over-voltage of magnitude comparable to lightning surge if no proper snubber circuit be used. The switching surge could damage power equipment of nearby trains in the same service zone, as observed in the TRA system. It is recommended that maximum tolerance of switching over-voltage be clearly specified in the procurement phase of new trains with switch-type converters then accurately verified in the commissioning phase to ensure proper preventive measure be installed.
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Dianchun Zheng, Zhonglin Zhang, Shihua Zhu, and Xiuquan Zhai. "Numerical analysis of very fast transient overvoltage in GIS." In 2011 1st International Conference on Electric Power Equipment - Switching Technology (ICEPE-ST). IEEE, 2011. http://dx.doi.org/10.1109/icepe-st.2011.6122929.

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Shanshan Yang and Gregory A. Franklin. "Effects of segmented shield wires on switching transient overvoltage study." In SOUTHEASTCON 2012. IEEE, 2012. http://dx.doi.org/10.1109/secon.2012.6196892.

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Huamao Zhan, Shaofeng Duan, Linzhi Yao, and Lin Zhao. "Influence of switching properties of the disconnector on very fast transient overvoltage." In 2017 IEEE Electrical Insulation Conference (EIC). IEEE, 2017. http://dx.doi.org/10.1109/eic.2017.8004674.

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Shanshan Yang and Gregory A. Franklin. "Switching transient overvoltage study simulation comparison using PSCAD/EMTDC and EMTP-RV." In SOUTHEASTCON 2012. IEEE, 2012. http://dx.doi.org/10.1109/secon.2012.6196891.

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Yang, Shanshan, and Gregory A. Franklin. "Switching transient overvoltage study simulation comparison using PSCAD/EMTDC and EMTP-RV." In IEEE SOUTHEASTCON 2013. IEEE, 2013. http://dx.doi.org/10.1109/secon.2013.6567369.

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