Дисертації з теми "Transient overvoltage"
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Laznevoy, A., Ірина Анатоліївна Башлак, Ирина Анатольевна Башлак, and Iryna Anatoliivna Bashlak. "Transient overvoltage and its effect on a substation." Thesis, Sumy State University, 2019. https://essuir.sumdu.edu.ua/handle/123456789/77004.
Повний текст джерелаGalliano, Francois. "Propagation and mitigation of Very Fast Transient Overvoltage in Gas Insulated Substation." Thesis, KTH, Elektroteknisk teori och konstruktion, 2015. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-160516.
Повний текст джерелаMycket snabba transienter (eng. Very Fast Transients) är överspänningar som skapas till exempel när en frånskiljare öppnas eller stängs (DS). På grund av de mycket högfrekventa påkänningar som de utövar på utrustningen och deras storlek (upp till 3 pu), utgör de en viktig fråga i utformningen av ultrahögspännings gasisolerade ställverk. Denna avhandling ger en allmän förståelse för mycket snabba transienta överspänningar (VFTO eller VFT) och undersöker olika metoder för dämpning, främst baserade på förlust av energi. . Främst diskuteras två lösningar för dämpning av VFTO: applicering av en semi resistiv och magnetisk beläggning kring ledaren eller använda magnetiska ringar. Båda är beroende av icke-linjäritet av strömförträngningseffekt och magnetiska förluster, båda metodernabehandlas på liknande sätt. En elektromagnetisk modell av båda systemen föreslås liksom ett sätt att modellera inverkan av anordningen på transienta systemets beteende. Utförandet av båda systemen måste verifieras genom experiment, men de båda bör avsevärt minska effekterna av VFTO.
Khan, Md Nazmus Shakib. "Transient Voltage Distribution in Bushing." Thesis, KTH, Skolan för elektroteknik och datavetenskap (EECS), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-292753.
Повний текст джерелаEn elektrisk genomföring är ett av de viktigaste elementen i en transformator. Spänningsvågor med branta fronter som impulsspänningar från blixtnedslag är ett oundvikligt elektromagnetiskt övergående fenomen som oftast sker i kraftöverförings- och distributionssystem. Genomföringen kan leda till att degraderas på grund av en sådan våg. Detta projekt handlar om fördelning av överspännings på transformatorgenomföringen under påverkan av elektromagnetisk transient respons, såsom blixtimpuls. För att förstå beteendet hos övergående respons på genomföringen är en korrekt modell av transformatorgenomföring inbyggd Comsol-flerfysik för att autentisera spänningsfördelningen. Den elektromagnetiska impulsvågen fortplantas från luftledningen som ansluter till transformatorn. Viss förståelse för det övergående beteendet hos en ledargenomföring har uppnåtts genom att studera påverkan av induktansegenskaper och hudeffektegenskaperna hos en flerskikts koaxialkabel på vågutbredningen, vilket har strukturerats i detta projekt för att förenkla modellen. Å andra sidan har hudeffektanalysen på genomföringens ledare beaktats i detta projekt med användning av verklig ledarsimulering i Comsol-modellen. Således blir det intressant att jämföra den riktiga ledarmodellen med den perfekta ledaren för genomföringen genom att analysera strömtäthetseffekten på den. I detta projekt simuleras flerskikt av koaxialkabel och transformatorgenomföring. Simuleringen utförs för tidsdomän och frekvensdomän i Comsol baserat på modellegenskaperna.
Bátora, Branislav. "Analýza ferorezonančního přepětí v elektrických sítích." Doctoral thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2014. http://www.nusl.cz/ntk/nusl-233633.
Повний текст джерелаEzzeddine, 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.
Повний текст джерелаMany 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.
Haddad, Abderrahmane. "Attenuation and limitation of transient overvoltages on transmission systems." Thesis, Cardiff University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.427994.
Повний текст джерелаQureshi, Suhail Aftab. "Calculation of fast transients in gas insulated substations." Thesis, University of Manchester, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.363514.
Повний текст джерелаGregory, 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.
Повний текст джерелаA 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)
Kunakorn, Anantawat. "A study of transient overvoltages from power electronic converters and their distribution in random-wound electrical machines." Thesis, Heriot-Watt University, 2000. http://hdl.handle.net/10399/565.
Повний текст джерелаGercek, Cem Ozgur. "Optimizing Transient And Filtering Performance Of A C-type 2nd Harmonic Power Filter By The Use Of Solid-state Switches." Master's thesis, METU, 2007. http://etd.lib.metu.edu.tr/upload/12608836/index.pdf.
Повний текст джерелаthe resistance of permanently connected damping resistor is to be optimized for minimization of voltage stresses on filter elements arising from switchings in transient state and for maximization of filtering effectiveness in the steady-state. Transformer inrush current during energization of power transformers and connection of filter bank to the supply are the major causes of voltage stresses arising on filter elements in transient state. These can be minimized by designing a highly damped C-type filter (low damping resistor) at the expense of inadequate filtering performance and high losses in the steady-state. On the other hand, higher damping resistance (high quality factor) is to be chosen in the design of C-type filter for satisfactory filtering of 2nd harmonic current component at the expense of higher voltage rating for capacitor bank and hence a more costly filter bank design. This drawback of conventional C-type 2nd harmonic filter circuit can be eliminated by subdividing damping resistor into two parallel parts
one is permanently connected while the other is connected to and disconnected from the circuit by back-to-back connected thyristor assemblies. The use of light triggered thyristors provides isolation between power stage and control circuit, and hence allows outdoor installation.
Mestas, Valero Patricia. "Controle adaptativo para religamento tripolar aplicado a linhas de transmissão com compensação reativa em derivação." [s.n.], 2011. http://repositorio.unicamp.br/jspui/handle/REPOSIP/260992.
Повний текст джерелаTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação
Made available in DSpace on 2018-08-19T10:56:05Z (GMT). No. of bitstreams: 1 MestasValero_Patricia_D.pdf: 4018272 bytes, checksum: 38a65b52b68046f67c3791c9b6ea2f7d (MD5) Previous issue date: 2011
Resumo: O presente trabalho descreve um novo método de controle adaptativo para chaveamento sincronizado de disjuntores durante a manobra de religamento tripolar de linhas de transmissão com compensação reativa em derivação. O objetivo principal do método desenvolvido é controlar as sobretensões transitórias e reduzir o tempo morto antes do religamento. Diferentes estratégias para controlar sobretensões decorrentes do religamento tripolar são descritas com a finalidade de diferenciar as vantagens do chaveamento sincronizado. Os benefícios potenciais a serem obtidos a partir do religamento tripolar rápido são expostos. O método de controle adaptativo desenvolvido consiste em identificar com antecedência a região ótima para o religamento, permitindo fechar o disjuntor já no primeiro mínimo do batimento da tensão entre os contatos do disjuntor após o tempo morto de atuação da proteção. Após os testes realizados utilizando um programa para simulação de transitórios eletromagnéticos (PSCAD/EMTDC), o método proposto foi implementado em protótipo (controlador). Este protótipo foi testado utilizando o Simulador Digital em Tempo Real (RTDS). As simulações em tempo real demonstraram a eficiência do método no controle das sobretensões e na redução do tempo morto. Finalmente, o método foi avaliado parametricamente para uma série de condições simuladas, incluindo diferentes níveis de compensação reativa em derivação, a influência da compensação série, a influência da transposição da linha de transmissão e os efeitos da variação do comprimento da linha. Além disto, outras simulações foram realizadas para comparar o desempenho dos métodos de controle existentes e do método proposto
Abstract: The present thesis describes a new adaptive control method for synchronous switching of circuit breakers during three-phase reclosing of shunt compensated transmission lines. The main objective of the developed method is to control the overvoltages and to reduce the dead time prior of reclosing. Several strategies to control overvoltages resulting from three-phase reclosing are described in order to differentiate the benefits of the proposed method. The potential benefits obtained from the developed controlled reclosing method are exposed. The proposed algorithm identified, in advance, the optimal region for reclosing of transmission line, allowing closing the circuit breaker at the first minimum voltage beat across circuit breaker, after protection dead time. After off-line testing using electromagnetic transients simulation program (PSCAD/EMTDC), the proposed method was also implemented in physical hardware. This hardware was then tested on a real-time transients simulator (RTDS). The real time simulations demonstrate the method efficiency to control overvoltages and to reduce the dead time. Finally, the method has been parametrically evaluated for a range of simulated conditions, including different shunt compensation levels, influence of series compensation, influence of transmission line transposition, effect of line lengths. In addition, simulations have been conducted to compare the performance of existing control method and the proposed method
Doutorado
Energia Eletrica
Doutor em Engenharia Elétrica
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.
Повний текст джерелаRamli, 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/.
Повний текст джерелаThomazella, Rogério [UNESP]. "Implementação computacional para avaliar os níveis de sobretensões atmosféricas induzidas em linhas de distribuição." Universidade Estadual Paulista (UNESP), 2004. http://hdl.handle.net/11449/90810.
Повний текст джерелаCoordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
O presente trabalho visa o desenvolvimento de uma ferramenta computacional confiável na análise e estimação dos níveis de tensões induzidas em linhas de distribuição. Neste contexto, utilizam-se ferramentas computacionais consolidadas, como o ATP (Alternative Transients Program), que combinado a um software desenvolvido em Visual Basic, permitem quantificar e avaliar o nível de sobretensões nas linhas de distribuição. Por meio de modificações nas técnicas clássicas de modelagem das descargas atmosféricas, foi possível a construção de um software em Visual Basic capaz de quantificar os valores das tensões induzidas em linhas de distribuição finitas. A avaliação dos níveis de sobretensões induzidas nas mesmas foi implementada pela associação deste software a um programa de simulação (ATP), a fim de se obter resultados fidedignos deste transitório. Tais resultados foram utilizados para se avaliar o desempenho das...
The present work aims at the development of a trustworthy computacional tool in the analysis and estimate of the levels of induced overvoltage in distribution network. In this context, consolidated computacional tools are used, as ATP (Alternative Transients Program), that combined with a software developed in Visual Basic (beginner's all-purpose symbolic instruction code), they allow to quantify and to evaluate the level of overvoltage in the distribution network. By the means of modifications in the classic techniques of modeling of the atmospheric discharges, the construction of a software in Visual Basic was possible to quantify the values of the induced overvoltage in a finite... (Complete abstract click electronic access below)
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.
Повний текст джерелаBukvišová, Zuzana. "Modelování rychlých přechodných dějů." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2017. http://www.nusl.cz/ntk/nusl-316921.
Повний текст джерелаThomazella, Rogério. "Implementação computacional para avaliar os níveis de sobretensões atmosféricas induzidas em linhas de distribuição /." Bauru : [s.n.], 2004. http://hdl.handle.net/11449/90810.
Повний текст джерелаBanca: Ivan Nunes da Silva
Banca: Luiz Gonzaga Campos Porto
Resumo: O presente trabalho visa o desenvolvimento de uma ferramenta computacional confiável na análise e estimação dos níveis de tensões induzidas em linhas de distribuição. Neste contexto, utilizam-se ferramentas computacionais consolidadas, como o ATP (Alternative Transients Program), que combinado a um software desenvolvido em Visual Basic, permitem quantificar e avaliar o nível de sobretensões nas linhas de distribuição. Por meio de modificações nas técnicas clássicas de modelagem das descargas atmosféricas, foi possível a construção de um software em Visual Basic capaz de quantificar os valores das tensões induzidas em linhas de distribuição finitas. A avaliação dos níveis de sobretensões induzidas nas mesmas foi implementada pela associação deste software a um programa de simulação (ATP), a fim de se obter resultados fidedignos deste transitório. Tais resultados foram utilizados para se avaliar o desempenho das... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: The present work aims at the development of a trustworthy computacional tool in the analysis and estimate of the levels of induced overvoltage in distribution network. In this context, consolidated computacional tools are used, as ATP (Alternative Transients Program), that combined with a software developed in Visual Basic (beginner's all-purpose symbolic instruction code), they allow to quantify and to evaluate the level of overvoltage in the distribution network. By the means of modifications in the classic techniques of modeling of the atmospheric discharges, the construction of a software in Visual Basic was possible to quantify the values of the induced overvoltage in a finite... (Complete abstract click electronic access below)
Mestre
Chen, Wei-Hsiang, and 陳韋翔. "Transient Overvoltage Suppression Strategys of Power Capacitors." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/53381838054331982405.
Повний текст джерела國立勤益科技大學
電機工程系
98
This paper aims to reduce the transient overvoltages problem occurred in switching shunt capacitor banks. Capacitor banks installed in power system are used to compensate the reactive power demand for improving the network’s voltage profile and decreasing the network’s losses. Capacitor banks may be switched on and off frequently during a typical day according to certain load curves. The switching actions will produce large transient overvoltages. These transients may cause serious power quality problems. This paper uses Alternative Transients Program (ATP) to compare the responses of several typical switching strategies such as voltage zero closing, voltage peak closing, installing current-limiting reactors and pre-installed resistors, then suggestions for reducing transients are proposed. According to the result, the method of pre-installed resistors has a greater tolerance for time deviation of switch closing than other methods; it also can effectively inhibit the three-phase transient overvoltages.
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.
Повний текст джерелаLee, Chang-Hsing, and 李長興. "Simulation and Analysis of the Very Fast Transient Overvoltage in Medium Voltage Systems." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/00471785969251281818.
Повний текст джерела國立清華大學
電機工程學系
99
The very fast transient overvoltage (VFTO) is a common transient phenomenon caused by the switching operation in the extra-high-voltage (EHV) gas insulated substation (GIS), and is characterized by its fast rising wavefront within nanoseconds. Besides the peak of VFTO higher than the breakdown voltage of insulation material, the main affection of VFTO on the equipments is the fast rising wavefront, causing the non-uniform electric field inside the insulation material, then leading the partial overvoltage inside the insulation material, and resulting in the accelerating aging of the insulation material. Furthermore, the very fast transient may cause electromagnetic interference and result in the malfunction of control instruments. As for the equipments in the secondary side of power transformer, the VFTO is thought to be small and less dangerous due to the mismatch of impedance. Therefore, most researches involving VFTO usually focus on the affection of VFTO on the GIS itself, and the equipments adjacent GIS or directly connected to GIS. Hence, there are few researches dealing with the VFTO in the secondary side of power transformer. However, a few field experiments showed that some root causes of medium voltage events were suspected to be the switching surge of GIS operation. Moreover, the authors measured the VFTO in 4.16 kV system in the 3rd nuclear power plant of Taipower at 2002, and the VFTO was, hence, confirmed to be able to transmit into medium voltage system. Therefore, this thesis takes the analysis of VFTO in medium voltage system as the major topic by simulating and measuring the VFTO in medium voltage system. Limited by the capabilities of software, ElectroMagnetic Transient Program (EMTP), it is impossible to simulate the transient phenomena of whole process of switching operation by the 1 ns time step. Therefore, most literatures estimated the affection of VFTO by the single strike simulation with the most series situation, such as 2.0 PU inter-contact breakdown voltage. However, according to the field measurement results in the 3rd nuclear power plant and the study of this thesis, the characteristics of VFTO in medium voltage system are not only affected by the inter-contact breakdown voltage, but also affected by the properties of whole process. Hence, this thesis is devoted to develop simulation method to simulate the whole process phenomena of disconnect switch (DS). This thesis gets the following results: 1. By the analysis of components’ characteristics, the notice is addressed for the simulation, and the simulation method for whole process phenomena of switching operation is proposed, which includes the proposition of an adequate simulation timestep and the high frequency recovery factor (HFRF) to adjust the maximum peak of VFTO simulated at this timestep; 2. By analysis of the simulation results, the properties of the VFTO transmitting into medium voltage system are characterized: the capacitive transfer of high turn-ratio transformer, the superposition effect of the oscillation caused by former restike superimposing into the following restrike, the three phases coupling caused by three-phase system, the duration of arcing time, and the properties of DS opening/closing; 3. By simulating the DS operating at different operation angle, the property of VFTO in medium voltage system is discussed including aforementioned factors; 4. By the several field measurement results, the recommendation is made for the measuring of VFTO in the medium voltage system.
(9826433), Rodney Peters. "Transient overvoltages in mine power systems." Thesis, 1998. https://figshare.com/articles/thesis/Transient_overvoltages_in_mine_power_systems/20341575.
Повний текст джерелаThis 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.
"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.
Повний текст джерелаDissertation/Thesis
Masters Thesis Electrical Engineering 2018
Gumede, Makhosonke. "In-service condition monitoring of polymer housed surge arrester within eThekwini Electricity." Thesis, 2015. http://hdl.handle.net/10321/1677.
Повний текст джерелаThe primary objective of this research was to investigate the failures occurring in the family of surge arresters used within EThekwini Electricity, making use of different diagnostic methods, such as leakage current testing (LC), infrared scanning (IR), and partial discharge (PD) measurements. The different diagnostic tests were used to assess the degradation process of the polymer housed surge arresters and their failure. The measurements were used for diagnosis of 120 kV/65 kA surge arresters of different brands. Tests were performed on surge arresters that were still in the system and these test results were compared with results from tests performed on failed units. Results obtained from the different tests were compared to the test results for different families or designs. An imperfect arrester will exhibit excessive heating when an electrical surge is discharged. The aforementioned tenets are the primary factors influencing degradation and causing failure of Metal Oxide Surge Arrester (MOSA) in a system. These factors can decrease creepage and flashover distance on insulation, which could result in a substantial increase in resistive leakage current, (which is a few microamperes in ideal condition), overheating, and PD formation on the zinc oxide varistor element. Therefore, it is extremely important to assess the status of the surge arresters whilst they are in service, firstly so that they can be removed from the system before they fail and, and secondly, to verify their condition, and their ability to effectively protect the substation apparatus. Using infrared inspection, valuable information of condition of surge arresters was obtained, heat inside the surge arresters was detected and this shows that IR analysis can therefore be considered as an additional method to assess the condition of polymer housed surge arresters. It was observed that partial discharge activity is an indication of degradation in arrester varistor. LC test, IR, and PD measurement were valuable in obtaining sufficient information for failure of surge arresters. In additional, during the visual internal inspection of arresters, evidence of punctures, treeing, tracking, and moisture masks were noted on ZnO blocks and seals. These results indicate that the moisture ingress through the sealing collar can cause unnecessary outages.
M