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"This paper deals with the electrical insulation of a gap bridged by a solid dielectric between a pair of electrodes in a vacuum, where the dielectric is a model of an insulating spacer holding electrodes in various vacuum devices. Such gap configuration is typical as a model for studying physical mechanisms of an electrical breakdown or a flashover in a vacuum, in which the insulation ability isconsiderably lower than a gap without any insulating spacers. Many researchers have long investigated the mechanisms of flashover, and it is believed that the charging of the insulator surface is the primary drive of such weakness. One of the effective approaches for studying mechanisms is to analyze the characteristic of charge accumulated on the insulator surface both by experiments and bynumerical analyses. This paper reviews previous works conducted by the author’s research group and demonstrates the difficulties we have encountered upon conducting the numerical analyses."

"A series of laboratory tests for electrical fires have been carried out by researchers, and some of the results have confirmed and been adopted as standard. However, the studies focus on electrical fires in PVC insulation material and the melting temperature and toxicity of PVC insulation. By focusing on heat conductors, the growth and spread of a fire can be eliminated by reducing the oxygen concentration, especially inside the compartment. Electrical fires are the most common cause of compartment and building fires both internationally and nationally, according to statistics (Liu & Benichou, 2008). Whatever the triggers are inside the electrical compartment on the connection, termination, or cable, this research looks into electrical fires caused by 1.0–1.5 mmsq electrical cables. Electrical fires in cables are normally started by increasing temperatures inside the cable conductor. By controlling and adjusting the oxygen concentration inside the electrical compartment under atmospheric concentration, one can hamper a fire’s start, trigger, propagation, and growth. This study investigates the effectiveness of oxygen concentration on preventing the growth of fires triggered by electrical cabling. A series of studies were created in laboratory scale in a horizontal compartment with oxygen levels of 19%, 17%, and 15%. This paper presents the results of this experiment by studying the effects of reducing oxygen concentration on the fire growth in cable network in a horizontal orientation. The results show that controlling the oxygen concentration at levels lower than atmospheric concentrations can effectively reduce the propensity for cable ignition and lower the fire propagation rate."

"Minyak transformator merupakan salah satu bahan isolasi yang paling baik digunakan untuk menjaga sistem isolasi pada semua transformator daya. Seiring dengan tingginya pengoperasian pada transformator dapat mengakibatkan temperatur dari minyak transformator meningkat. Kejadian tersebut dapat mengakibatkan deteriorasi pada minyak transformator seperti terjadinya gangguan thermal decomposition yang mengakibatkan menurunnya kekuatan isolasi dari minyak. Oleh karena itu kondisi minyak transformator perlu diperiksa secara berkala untuk mencegah terjadinya kegagalan pengoperasian. Analisis dilakukan berdasarkan kandungan gas yang terurai pada minyak transformator dengan membandingkan beberapa metode analisis, yaitu metode TDCG,Roger’s Ratio, Doernenburg Ratio dan Duval Triangle. Analisis dilakukan dengan membandingkan dengan standar internasional yang berlaku untuk mendapatkan hasil analisis yang valid. Hasil analisis yang didapatkan adalah transformator dengan kondisi baik tidak memerlukan analisis lebih mendalam pada masing-masing parameternya, sedangkan pada transformator dengan kondisi buruk dapat dilakukan analisis lebih mendalam untuk mendiagnosa gangguan yang mungkin terjadi. Gangguan yang terjadi pada Transformator 2 berdasarkan metode TDCG adalah berada di kondisi 4, berdasarkan metode Roger’s Ratio dan Duval Triangle mengalami thermal fault dengan t>700° Celcius dan metode mengalami kondisi thermal decomposition

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Transformer oil is one of the best insulating materials used to maintain an insulating system on all power transformers. Along with the high operation of the transformer can cause the temperature of the transformer oil to increase. This incident can result deterioration of transformer oil such as thermal decomposition which will cause a decrease especially for the insulating strength of the oil. Therefore, the condition of transformer oil needs to be checked periodically to prevent operating failures. The analysis was carried out based on the dissolved gas content in the transformer oil by comparing several analytical methods, namely the TDCG method, Roger’s Ratio, Doernenburg Ratio and Duval Triangle method. The analysis is carried out by comparing with applicable international standards to obtain valid analysis results. The results of the analysis obtained are transformers with good conditions do not require more in-depth analysis of each parameter, while transformers with bad conditions can be analyzed more deeply to diagnose possible disturbances. The disturbance that occurs in Transformer 2 based on the TDCG method is in condition 4, based on the Roger's Ratio  and the Duval Triangle experiencing a thermal fault with t>700° Celsius and the Doernenburg Ratio experiencing thermal decomposition conditions."

"Gardu Induk Tegangan Ekstra Tinggi (GITET) 500 kV KEMBANGAN merupakan Salah satu gardu induk di wilayah operasi PLN RJKB ? UPT Jakarta Barat. GITET 500 kV Kembangan terdiri dari 2 (dua) buah IBT 500/150 kV, 500 MVA dijadikan sebagai salah satu pemasok utama di wilayah Jakarta Barat diantaranya : menyuplai GI 150 kV Kembangan, New Senayan, Ciledug, Cikupa, Pasar kemis, Sepatan, Teluk naga, Jatake, Tangerang dan Maximangando. Pada tanggal 27 September 2009 pukul 08.06 WIB terjadi gangguan pada instalasi IBT-1 500/150 kV phasa T dengan indikasi relai : Differential (87T), REF (87NT), OCR moment (50), Bucholz, Jansen, Suddent Pressure, Oil Temperature dan Winding Temperature. Dari hasil perolehan data disimpulkan bahwa gangguan disebabkan oleh pemburukan kertas isolasi yang telah berlangsung lama, sehingga terjadi hubungan pendek (short circuit) pada internal transformator. Pada saat gangguan terjadi, beban yang disuplai oleh IBT-1 dan IBT-2 masih rendah (IBT-1: 108 MW = 27% dari beban nominal dan IBT-2: 113 MW=28.25% dari beban nominal) dan IBT-2 sebesar 113 MW, sehingga akibat kejadian ini tidak terjadi pemadaman, karena beban yang ada dapat ditanggung oleh IBT-2 yang tidak terganggu.

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Kembangan High Voltage sub station (GITET) 500 kV is One of the substations in the area of operations of PLN RJKB - UPT West Jakarta. 500 kV Kembangan Sub-station consists of two (two) IBT 500/150 kV, 500 MVA used as one of the main suppliers in the West Jakarta area including: supplying the 150 kV Sub station Kembangan, New Senayan, Ciledug, Cikupa Market Thursday, Sepatan, Gulf dragon, Jatake, Tangerang and Maximangando. On September 27, 2009, at 8:06 pm disruptions occurred at IBT-1 installation phase-T with an indication of relay: Differential (87T), REF (87NT), OCR Moment (50), Bucholz, Jansen, Suddent Pressure, Oil Temperature and winding temperature.

From the results of data acquisition is concluded that the disruption caused by the deterioration of insulating paper that has lasted a long time, resulting in short circuit on the internal transformer. At the time disturbance occurs, the load supplied by the IBT-1 and IBT-2 was relatively low (IBT-1: 108 MW = 27% of the nominal load and IBT-2: 113 MW = 28,25% of the nominal load), so this incident does not occur due to extinction, because the load can be borne by the IBT-2 is not discupted."