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Irfan Nurhadi, ANALISIS PARTIAL DISCHARGE PADA SALURAN KABEL TEGANGAN MENENGAH 20 KV (STUDI ASSESMEN SKTM DI PT PLN (PERSERO) UP3 MENTENG). Dosen Pembimbing : Drs. Ir. Parjiman, M.T dan Mochammad Djaohar, S.T, M.Sc Penelitian ini bertujuan untuk untuk mengetahui status kondisi kabel terhadap tegangan munculnya Partial Discharge, serta status kabel terhadap pelepasan muatan Partial Discharge. Pengukuran dilakukan di PT PLN (Persero) UP3 Menteng pada Penyulang Kambing Segmen TD 09-PM 4A. Penelitian ini menggunakan metode deskriptif. Penelitian ini dilakukan pengukuran pelepasan muatan dan tegangan pada setiap fasa pada segmen tersebut. Setelah dilakukan pengukuran pelepasan muatan satu segmen maka selanjutnya dilakukan analisis data untuk mengetahui nilai Partial Discharge kemudian nilai tersebut diakumulasikan hingga menjadi kesimpulan kondisi resiko kegagalan kabel yang mengacu pada standar yang telah ditentukan oleh PLN. Hasil penelitian menunjukkan bahwa status kabel terhadap tegangan muncul Partial Discharge. Nilai PDIV sebesar 17,3 kV perfasa dapat diartikan PDIV > Uo. Nilai PDEV sebesar 8 kV perfasa, dapat diartikan PDEV U0 dan PDEV < U0 masuk kategori status kabel cukup buruk dengan Point 2. Status Kabel Terhadap Besar Pelepasan Muatan. Nilai PD max dan PD Level berkisar dibawah 500 pC. Sehingga dapat diartikan besar muatan dibawah atau sama dengan 500 pC, Y < 500 pC atau Y = 500 pC masuk kategori status kabel baik dengan point 1. Jika pont 2 dan point 1 dijumlahkan maka hasilnya poin 3. Poin 3 dapat disimpulkan dengan warna hijau tua. Resiko kegagalan kabel pada segmen TD 09 to PM 4A adalah rendah dan status kabel tersebut cukup baik. Tindak lanjutnya yaitu dalam jangka waktu 12 bulan, segmen ini harus kembali diukur untuk mengetahui kondisi resiko kegagalan kabel. Kata Kunci: SKTM, Partial Discharge, PDIV, PDEV, Resiko Kegagalan Kabel Irfan Nurhadi, ANALYSIS OF PARTIAL DISCHARGE ON THE 20 KV MEDIUM VOLTAGE CABLE LINES (STUDY OF SKTM ASSESSMENT IN PT PLN (PERSERO) UP3 MENTENG). Mentor : Drs. Ir. Parjiman, M.T and Mochammad Djaohar, ST, M.Sc This study aims to determine the status of the cable condition to the emergence voltage of Partial Discharge, as well as the status of the cable to discharge the Partial Discharge. Measurements were made at PT PLN (Persero) UP3 Menteng on TD 09-PM 4A Segment Goat Feeders. This research uses a descriptive method. This study carried out measurements of the release of charge and voltage at each phase in the segment. After measuring the discharge of a single segment, data analysis is then performed to determine the value of Partial Discharge, then the value is accumulated to conclude the condition of cable failure risk that refers to standards set by PLN. The results showed that the status of the cable to the voltage appears Partial Discharge. PDIV value of 17.3 kV can be interpreted PDIV> Uo. PDEV value of 8 kV, can be interpreted PDEV U0 and PDEV

This paper presents an experimental verification of a PDIV model for twisted-pair magnet wires (TPMW). The model is physically rooted in an inception criterion based on secondary electron feedback and parametrizes the PDIV of wedge-shaped gas gaps (such as TPMW) solely in terms of its reduced coating thickness—the ratio of coating thickness to its relative permittivity. According to the literature, the coating’s permittivity and thickness should play a significant role in determining the PDIV. Still, no explicit quantification of their concurrent effects is often given, and they are frequently treated as decoupled parameters. Therefore, extensive measurements of PDIV of samples analogous to TPMW coated with dielectric materials of different permittivity (sealed and unsealed alumina, silicone polyester, and perfluoroalkoxy alkane) and thickness (≈45 to 80 μm) are performed. The PDIV of the test samples is determined under sinusoidal test voltage in the frequency between 10 to 60 000 Hz. It is shown that the PDIV can be predicted based on the relative permittivity and thickness of the coating, and the frequency dependence is due only to the change of permittivity with frequency. Temperature and pressure are kept approximately constant at their ambient values (ca. 23 °C & 970 mbar), and only dry air is used to exclude the effect of humidity on the insulation’s permittivity. Ultimately, the role of surface charge is discussed qualitatively by comparing the PDIV with the partial discharge extinction voltage (PDEV) and their repetitive counterparts (RPDIV, RPDEV)., IEEE Transactions on Dielectrics and Electrical Insulation, ISSN:1070-9878, ISSN:1558-4135

International audience; This paper provides a robust experimentalsimulation approach in predicting the Partial discharge inception voltage (PDIV) for aeronautical applications. First, two polymers used as insulators in aeronautic components have been selected in this work, a polyimide and a polyetheretherketone. To study the electrical behavior of these materials, extensive dielectric spectroscopy measurements are carried out for different electric fields, temperatures and frequencies (E, T, and f). Then, a needleplane configuration is adopted for PDIV modeling using finiteelement method (FEM). As the model is strongly dependent upon the accurate estimation of the electric field, dielectric characterizations results are integrated in simulations to improve the precision of calculations. Thereafter, the PDIV can be estimated with the aid of Townsend's theory. Finally, a comparison between measured and computed PDIV values is presented and discussed.

Aquest projecte exposa el comportament de les descàrregues parcials (DP’s) en els cables de MT i els seus accessoris. S’estudia quin és el procés de formació, l’evolució, la classificació, i les conseqüències de les DP’s. A més, es comparen les metodologies de detecció Online i Offline, enfrontant els seus avantatges i inconvenients; S’explica el fonament de reflectometria, per la qual es pot determinar la posició física de les DP’s, qüestió imprescindible per una eventual acció correctora. Per últim, la part pràctica consisteix en replicar diferents defectes de muntatge sobre accessoris, i avaluar quin és el comportament de les DP’s segons l’anàlisi del seu patró resolt en fase i la seva empremta dactilar (fingerprints), obrint un camí per a la seva caracterització en diferents instal·lacions. Este proyecto expone el comportamiento de las descargas parciales (DP'S) en los cables de MT y sus accesorios. Se estudia cuál es el proceso de formación, la evolución, la clasificación, y las consecuencias de las DP'S. Además, se comparan las metodologías de detección Online y Offline, enfrentando sus ventajas e inconvenientes; Se explica el fundamento de reflectometría, por la que se puede determinar la posición física de las DP's, cuestión imprescindible para una eventual acción correctora. Por último, la parte práctica consiste en replicar diferentes defectos de montaje sobre accesorios, y evaluar cuál es el comportamiento de las DP s según el análisis de su patrón resuelto en fase y su huella dactilar (fingerprints), abriendo un camino para la su caracterización en diferentes instalaciones. This project exposes the behavior of partial discharges (PD's) in MV cables and their accessories. The formation process, evolution, classification and consequences of PD's are studied. In addition, the Online and Offline detection methodologies are compared, facing their advantages and disadvantages; the basis of reflectometry is explained, by which the physical position of PD's can be determined, an essential issue for an eventual corrective action. Finally, the practical part consists of replicating different assembly defects on fixtures, and evaluating the behavior of the PD's according to the analysis of their phase-resolved pattern and fingerprints, opening a way for their characterization in different installations.

Reducing CO2 emissions is a major challenge for Europe in the years to come. Nowadays, transport is the source of 24% of global CO2 emissions. Aviation accounts for only 2% of global CO2 emissions. However, air traffic is booming and concerns are emerging. For instance, CO2 emissions from air traffic have increased by 61% in Sweden since the 1990s. This explains the emergence of the "Flygskam" movement which is spreading in more and more European countries. It is in this context that the European Union launched in September 2016 the project Hybrid Aircraft Academic research on Thermal and Electrical Components and Systems (HASTECS). The consortium brings together different laboratories and Airbus. This project is part of the program "Clean Sky 2" which aims to develop a greener aviation. The ambitious goal is to reduce CO2 emissions and the noise produced by aircraft by 20% by 2025. To do that, the consortium is studying a serial hybrid architecture. Propulsion is provided by electric motors. Two targets are defined. In 2025, the engines must reach a power density of 5kW/kg, including the cooling system. In 2035, the power density of the engines will be doubled to reach 10kW/kg. To reach these targets, the voltage level will be considerably increased, beyond one kilovolt. The risk of electric discharges in the stators of electric motors is considerably increased. The objective of this thesis is to develop a tool to assist in the design of the primary Electrical Insulation System (EIS) of the stator of an electric motor controlled by a converter. It is organized in 5 parts. The first part begins by clarifying the issues and challenges of a greener aviation. The electric motor stator EIS is developed. Finally, the constraints that apply to the EIS in the aeronautical environment are identified. The second part presents the different types of electric discharges that can be found. The main risk comes from Partial Discharges (PD) which gradually deteriorate the EIS. The main mechanism for explaining the appearance of PD is the electronic avalanche. The Paschen criterion makes it possible to evaluate the Partial Discharge Inception Voltage (PDIV). Different techniques are used to detect and measure the activity of PD. Numerical models are used to evaluate the PDIV. The third part presents an original method for determining the electric field lines in an electrostatic problem. It only uses a scalar potential formulation. The fourth part presents an experimental study to establish a correction of the Paschen criterion. An electric motor winding is very far from the hypotheses in which this criterion was originally defined. Finally, the fifth part is devoted to the development of the SIE design aid tool. Graphs are generated to provide recommendations on the sizing of the various insulators in a stator slot. A reduction in the PDIV due to a combined variation in temperature and pressure is taken into account.; La réduction des émissions de CO2 est un enjeu majeur pour l'Europe dans les années à venir. Les transports sont aujourd'hui à l'origine de 24% des émissions globales de CO2. L'aviation ne représente que 2% des émissions globales de CO2. Cependant, le trafic aérien est en pleine expansion et, déjà, des inquiétudes apparaissent. A titre d'exemple, en Suède, depuis les années 1990, les émissions de CO2 dues au trafic aérien ont augmenté de 61%. Ce constat explique l'apparition du mouvement "Flygskam" qui se repend dans de plus en plus de pays Européen. C'est dans ce contexte que l'Union Européenne a lancé en septembre 2016 le projet Hybrid Aircraft Academic research on Thermal and Electrical Components and Systems (HASTECS). Le consortium regroupe différents laboratoires et Airbus. Ce projet s'inscrit dans le programme "Clean Sky 2" qui vise à développer une aviation plus verte. L'objectif ambitieux est de réduire de 20% les émissions de CO2 et le bruit produits par les avions d'ici 2025. Pour cela, le consortium étudie une architecture hybride de type série. La propulsion est assurée par des moteurs électriques. Deux cibles ont été définies. En 2025, les moteurs doivent atteindre une densité de puissance de 5kW/kg, système de refroidissement inclus. En 2035, la densité de puissance des moteurs sera doublée pour atteindre 10kW/kg. Pour atteindre ces cibles, le niveau de tension sera considérablement augmenté, au-delà du kilovolt. Le risque de décharges électriques dans les stators des moteurs électriques est considérablement accru. L'objectif de cette thèse est de mettre au point un outil d'aide au design du Système d'Isolation Electrique (SIE) primaire du stator de moteur électrique piloté par convertisseur. Elle est découpée en cinq parties. La première partie commence par préciser les enjeux et défis d'une aviation plus verte. Le SIE du stator de moteur électrique est développé. Enfin, les contraintes qui s'appliquent sur le SIE dans l'environnement aéronautique sont identifiées. La deuxième partie présente les différents types de décharges électriques que l'on peut retrouver. Le principal risque vient des Décharges Partielles (DP) qui détériorent peu à peu le SIE. Le principal mécanisme pour expliquer l'apparition des DP est l'avalanche électronique. Le critère de Paschen permet d'évaluer le Seuil d'Apparition des Décharges Partielles (SADP). Différentes techniques permettent de détecter et mesurer l'activité des DP. Des modèles numériques permettent d'évaluer le SADP. La troisième partie présente une méthode originale pour déterminer les lignes de champ électrique dans un problème électrostatique. Elle n'utilise qu'une formulation en potentiel scalaire. La quatrième partie présente une étude expérimentale pour établir une correction du critère de Paschen. Un bobinage de moteur électrique est très loin des hypothèses dans lesquelles ce critère a été originellement défini. Enfin, la cinquième partie est consacrée à l'élaboration de l'outil d'aide au design du SIE. Des abaques sont construites afin de fournir des recommandations sur le dimensionnement des différents isolants dans une encoche de stator. Une réduction du SADP due à une variation combinée de la température et de la pression est prise en compte.

Reducing CO2 emissions is a major challenge for Europe in the years to come. Nowadays, transport is the source of 24% of global CO2 emissions. Aviation accounts for only 2% of global CO2 emissions. However, air traffic is booming and concerns are emerging. For instance, CO2 emissions from air traffic have increased by 61% in Sweden since the 1990s. This explains the emergence of the "Flygskam" movement which is spreading in more and more European countries. It is in this context that the European Union launched in September 2016 the project Hybrid Aircraft Academic research on Thermal and Electrical Components and Systems (HASTECS). The consortium brings together different laboratories and Airbus. This project is part of the program "Clean Sky 2" which aims to develop a greener aviation. The ambitious goal is to reduce CO2 emissions and the noise produced by aircraft by 20% by 2025. To do that, the consortium is studying a serial hybrid architecture. Propulsion is provided by electric motors. Two targets are defined. In 2025, the engines must reach a power density of 5kW/kg, including the cooling system. In 2035, the power density of the engines will be doubled to reach 10kW/kg. To reach these targets, the voltage level will be considerably increased, beyond one kilovolt. The risk of electric discharges in the stators of electric motors is considerably increased. The objective of this thesis is to develop a tool to assist in the design of the primary Electrical Insulation System (EIS) of the stator of an electric motor controlled by a converter. It is organized in 5 parts. The first part begins by clarifying the issues and challenges of a greener aviation. The electric motor stator EIS is developed. Finally, the constraints that apply to the EIS in the aeronautical environment are identified. The second part presents the different types of electric discharges that can be found. The main risk comes from Partial Discharges (PD) which gradually deteriorate the EIS. The main mechanism for explaining the appearance of PD is the electronic avalanche. The Paschen criterion makes it possible to evaluate the Partial Discharge Inception Voltage (PDIV). Different techniques are used to detect and measure the activity of PD. Numerical models are used to evaluate the PDIV. The third part presents an original method for determining the electric field lines in an electrostatic problem. It only uses a scalar potential formulation. The fourth part presents an experimental study to establish a correction of the Paschen criterion. An electric motor winding is very far from the hypotheses in which this criterion was originally defined. Finally, the fifth part is devoted to the development of the SIE design aid tool. Graphs are generated to provide recommendations on the sizing of the various insulators in a stator slot. A reduction in the PDIV due to a combined variation in temperature and pressure is taken into account., La réduction des émissions de CO2 est un enjeu majeur pour l'Europe dans les années à venir. Les transports sont aujourd'hui à l'origine de 24% des émissions globales de CO2. L'aviation ne représente que 2% des émissions globales de CO2. Cependant, le trafic aérien est en pleine expansion et, déjà, des inquiétudes apparaissent. A titre d'exemple, en Suède, depuis les années 1990, les émissions de CO2 dues au trafic aérien ont augmenté de 61%. Ce constat explique l'apparition du mouvement "Flygskam" qui se repend dans de plus en plus de pays Européen. C'est dans ce contexte que l'Union Européenne a lancé en septembre 2016 le projet Hybrid Aircraft Academic research on Thermal and Electrical Components and Systems (HASTECS). Le consortium regroupe différents laboratoires et Airbus. Ce projet s'inscrit dans le programme "Clean Sky 2" qui vise à développer une aviation plus verte. L'objectif ambitieux est de réduire de 20% les émissions de CO2 et le bruit produits par les avions d'ici 2025. Pour cela, le consortium étudie une architecture hybride de type série. La propulsion est assurée par des moteurs électriques. Deux cibles ont été définies. En 2025, les moteurs doivent atteindre une densité de puissance de 5kW/kg, système de refroidissement inclus. En 2035, la densité de puissance des moteurs sera doublée pour atteindre 10kW/kg. Pour atteindre ces cibles, le niveau de tension sera considérablement augmenté, au-delà du kilovolt. Le risque de décharges électriques dans les stators des moteurs électriques est considérablement accru. L'objectif de cette thèse est de mettre au point un outil d'aide au design du Système d'Isolation Electrique (SIE) primaire du stator de moteur électrique piloté par convertisseur. Elle est découpée en cinq parties. La première partie commence par préciser les enjeux et défis d'une aviation plus verte. Le SIE du stator de moteur électrique est développé. Enfin, les contraintes qui s'appliquent sur le SIE dans l'environnement aéronautique sont identifiées. La deuxième partie présente les différents types de décharges électriques que l'on peut retrouver. Le principal risque vient des Décharges Partielles (DP) qui détériorent peu à peu le SIE. Le principal mécanisme pour expliquer l'apparition des DP est l'avalanche électronique. Le critère de Paschen permet d'évaluer le Seuil d'Apparition des Décharges Partielles (SADP). Différentes techniques permettent de détecter et mesurer l'activité des DP. Des modèles numériques permettent d'évaluer le SADP. La troisième partie présente une méthode originale pour déterminer les lignes de champ électrique dans un problème électrostatique. Elle n'utilise qu'une formulation en potentiel scalaire. La quatrième partie présente une étude expérimentale pour établir une correction du critère de Paschen. Un bobinage de moteur électrique est très loin des hypothèses dans lesquelles ce critère a été originellement défini. Enfin, la cinquième partie est consacrée à l'élaboration de l'outil d'aide au design du SIE. Des abaques sont construites afin de fournir des recommandations sur le dimensionnement des différents isolants dans une encoche de stator. Une réduction du SADP due à une variation combinée de la température et de la pression est prise en compte.

Vegetable oils have been an alternative to mineral oil for oil-immersed transformers due to concern on less flammable, environmental-friendly, biodegradable, and sustainable resources of petroleum-based insulating oil. This paper presents the effect of electrical discharges (200 up to 1000 discharges) under 50 Hz inhomogeneous electric field on the properties (acidity, water content, and breakdown voltage) of two varieties of vegetable based insulating oils; i) natural ester (NE) and ii) low viscosity insulating fluids derived from a natural ester (NELV). Results show the water content, acidity and breakdown voltage of NE fluctuate due to applied discharges, while NELV display insignificant changes. Hence, results indicate that the low viscosity insulating fluids derived from natural ester tend to maintain their properties compared to natural ester.

Partial discharge (PD) detection is a fundamental test for the design and diagnosis of insulation systems, particularly organic materials which must operate throughout their whole life without PD. The measurement of Partial Discharge Inception Voltage (PDIV) and Repetitive Partial Discharge Inception Voltage (RPDIV), the latter defined for power electronic-type supply, is therefore a key issue for the design and qualification tests of Type I insulation system of rotating machines fed by power converters. While experience and technology for PD inception measurements under sinusoidal voltage supply is well established, the same does not hold under repetitive-pulse voltage waveforms, such as those provided by inverters. In addition, electromagnetic noise generated by electronic switch commutation can overlap with PD pulses signals and this is even more cumbersome when fast rise-time components are employed, such as GaN or SiC semiconductors. Moreover, this is also the condition which is the most stressful for stator wire insulation. This work investigates methods to detect PD pulses on enameled wires, rejecting noise efficiently, under repetitive impulsive voltages with different rise times, from 60 ns to 1000 ns. The proposed techniques can be implemented to achieve un-supervised noise rejection, which would be an important goal for both off-line and on-line PD testing.

This paper highlights the effects voltage supply waveform can have on partial discharge, PD, characteristics in insulation systems of rotating machines fed by power electronics drives. While standards allow both sinusoidal and repetitive voltage impulse waveforms to be used for insulation design and type tests, the dependence of PD on the voltage waveform implies that the machine design and performance can be affected significantly by the waveform. Partial discharge inception voltage, partial discharge patterns and insulation life are, in fact, dependent on the type of test waveform. This can affect significantly the design of machine insulation system.

The partial discharge inception voltage (PDIV) and the repetitive partial discharge inception voltage (RPDIV) are key parameters for the characterization of the insulation system of rotating machines fed by power converters. In particular, these quantities have a fundamental role in the design and qualification of Type I insulation which has to last all life without partial discharges (PD). This paper analyzes the two definitions, taken from the IEC 60034-18-41 and IEC 60034-18-42 standards, and shows potential discrepancies which can affect significantly insulation system design, especially going from two-level inverter to sinusoidal waveforms.

The reliability of low-voltage inverter-fed motors is highly dependent on the inception of partial discharges. The effect of impulsive waveform parameters must be investigated to predict the repetitive partial discharge inception voltage (RPDIV) and define test procedures that can indicate properly the behavior in service of the insulation system. This paper focuses on the RPDIV of magnet wires using twisted pairs subjected to repetitive unipolar impulsive voltage waveforms. The effects of supply frequency (5 to 200 kHz) at pressure levels that are typical for aircraft (20 to 100 kPa) is examined. Results show that RPDIV steadily decreases with frequency up to 100 kHz where it reaches a plateau. This behavior is explained as an effect of the oscillations that inevitably exist in the applied voltage waveform. Therefore, a conservative estimate of the RPDIV could be achieved by raising the supply frequency well above the operation frequency. In the experiments, the RPDIV is decreasing linearly with pressure. If this behavior could be confirmed for other insulation systems, the design of systems working at pressures typical of aircraft would result relatively easy.

Nowadays the massive adoption of electronic converters to supply electrical motors leads to critical problems during the normal operation. In fact when the motors are supplied by electronic converters, the stator insulating system could be subjected to over voltages due to reflection and resonance phenomena. Frequently this over voltages exceed the partial discharge inception voltage and partial discharge activity incepts. The presence of partial discharge activity implies the degradation of the dielectric characteristics of the type I insulating system and in the short-medium time, leads to a total breakdown discharge. Three different types of type I insulating system used in rotating electrical machines fed from inverters have been considered and studied. The PDIV and RPDIV at different temperatures have been measured and compared. During this research study the stators of asyncronous motors have been subjected to sinusoidal waveform and unipolar positive voltage pulses at different temperatures. In order to perform the RPDIV measurements a modified surge tester has been used so to apply unipolar positive voltage pulses at the terminals of the windings. The correlation between the repetitive partial discharge inception voltage and the partial discharges inception voltage measured at different temperatures has been studied.

The dielectric strength of pure nynas oil can be enhanced by adding various nanoparticles such as nanoalumina (Al2O3). To see the effect of the addition of alumina nanoparticles, 4 types of nynas oil have been prepared with the addition of nanoalumina particles by 0.00%, 0.010%, 0.015% and 0.020%. All samples were tested for dielectric breakdown voltage and partial discharge inception voltage (PDIV) test at room temperature with reference to IEC 60156 test standards. The results showed that the nanonynas oil breakdown voltage increased by 6% and the value of the partial discharge inception voltage also higher than that of pure oil. Keywords : Mineral oil , alumina , brekadown voltage, partial discharge inception voltage Abstrak Kekuatan dielektrik minyak transformator nynas nitro murni dapat ditingkatkan dengan menambahkan berbagai partikel nano seperti nanoalumina (Al 2 O 3 ).Penelitian ini bertujuan untuk melihat effek penambahan partikel nano alumina terhadap karakteristik tegangan tembus dan tegangan insepsi peluahan sebagian. Empat jenis minyak nynas dengan komposisi penambahan partikel nanoalumina sebesar 0.00%, 0.010%, 0.015% dan 0.020% diuji tegangan tembus dielektrik, tegangan insepsi peluahan sebagian (PDIV) pada suhu ruang dengan merujuk kepada standar pengujian IEC 60156. Hasil menunjukkan bahwa tegangan tembus minyak nanonynas meningkat sebesar 6% dan nilai tegangan insepsi dan peluahan sebagian lebih tinggi dibandingkan dengan minyak murni. Kata Kunci : Minyak nynas nitro libra, alumina (AL 2 O 3 ), tegangan tembus, PDIV

U ovom radu smo opisali osnovne principe mjerenja parcijalnih izbijanja (PI) kabela off-line i on line metodom te pojasnili osnovne pojmove za razumijevanje i korištenje ove metode. S obzirom na veliki broj kabela u distribucijskoj mreži, nije realno očekivati da se svi kabeli dijagnostički detaljno analiziraju. U tu svrhu je korisno pomoću ručnog detektora PI napraviti on- line predselekciju kabela na kojima će se raditi detaljnija dijagnostička analiza. Odabrane dionice se detaljno analiziraju off-line, pomoću uređaja za dijagnostiku PI. PI u kabelu se mogu locirati analizom izmjerenih podataka. Kod ostalih dijagnostičkih metoda dobijemo opći uvid u stanje izolacije dok PI imaju u pravilu lokalni karakter. Na ovaj način možemo locirati loše napravljenu spojku ili kabelsku glavu i preventivno ih zamijeniti.

International audience; The presence of conducting particles is a well-recognized threat to Gas-Insulated System (GIS) equipments. This study computes the electric field strength in simulated GIS model in the presence of conducting particle adhering to the spacer surface. The simulation results will be helpful to address the difficulties in acquiring accurate measurement and analysis of electric field non-uniformity in GIS due to the presence of conducting particles. The degree of electric field non-uniformity was identified by evaluating the electric field on large number of points within the area between the two electrodes. The information gathered from the simulation was used in estimating partial discharge inception voltage (PDIV) for the parallel-plane electrode configuration. The estimated PDIV values were confirmed by the experimental investigation using the IEC 60270 method.