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"The book introduces the reader to the major components of a high voltage system and the different insulating materials applied in particular equipments.During a review of these materials, measurable properties suitable for condition assessment are identified. Analyses are included of some of the insulation fault scenarios that may occur in power equipment.The basic facilities for carrying out tests on the internal and external insulation structures at high and low voltages are described. Tests and measurements according to specifications, on-site requirements and research investigations are considered.Advances in the application of digital techniques for detection and analyses of partial discharges are discussed and methods in use, or under development, for service condition monitoring are described. These include the utilization of new sensors, the solution of online problems associated with noise rejection and the adaptation of artificial intelligence techniques for incipient fault diagnosis.The subject matter of the book is suitable for final year courses in electrical power engineering, short courses in insulation condition assessment and postgraduate programmes. Power system engineers associated with high voltage equipment should find the book of value in relation to fault investigations, maintenance requirements, insulation testing and condition monitoring."

"Skripsi ini dibuat dengan pengkajian dari dua prosedur pengukuran untuk diagnosis sistem isolasi pada generator tegangan tinggi. Pengukuran dapat dibagi menjadi dua bagian, yaitu pengukuran secara online dan offline. pengukuran secara offline terdiri atas resistansi isolator, faktor disipasi, dan peluahan parsial, sedangkan pengukuran secara online hanya terdiri atas peluahan parsial. IEEE and IEC telah membuat standar yang disebut praktik yang direkomendasikan atau spesifikasi teknis untuk mengukur resistansi isolator, faktor disipasi, dan peluahan parsial dengan menggunakan peralatan diagnostik elektris. Pengukuran secara offline akan dibandingkan dengan pengujian sebelumnya untuk melihat sejauh mana degradasi isolator yang terjadi. Pengukuran secara online didasarkan pada perubahan beban dan waktu kerja dari mesin tersebut. Parameter ketika mesin bekerja seperti beban, tekanan gas pendingin akan dianalisis untuk melihat bagaimana parameter tersebut mempengaruhi degradasi dari sistem isolasi. Pengujian secara offline menunjukkan bahwa fasa R memiliki kondisi isolator terburuk, fasa S memiliki penurunan kualitas isolator yang paling signifikan dan, fasa T memiliki kualitas dan stabilitas nilai isolator bila dibandingkan dengan fasa lainnya. Selain itu, pengujian peluahan parsial menunjukkan telah terjadi delaminasi tape layer pada ketiga fasa yang diakibatkan adanya perubahan nilai vibrasi yang signifikan selama pengoperasian mesin. Pengujian secara online menunjukkan bahwa fasa S memiliki perubahan arus dan daya disipasi yang paling besar dibandingkan fasa lainnya seiring bertambahnya waktu pengoperasian dan meningkatnya pembebanan.

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This work is based on the study of two different measurements procedures for the diagnosis of insulation systems of high voltage generators. The measurement can be conducted into two ways, offline or online measurement. The offline measurements consist of Insulation Resistance, Partial Discharge, and Dissipation Factor measurement, meanwhile online measurements consist only partial discharge measurement. The measurements were done in stator windings not only to check the quality but also for the investigation of changes in operating processes.

IEEE and IEC have created standards called recommended practices or technical specifications to address polarization index, dissipation factor, and offline online PD measurement using electrical diagnostic equipment. The offline measurement will be comparated with previous measurement to see how degradation takes place.

The online measurement will be based on on load variable and machine rsquo s working hour. Also, the online parameter such as load, vibration, coolers pressure, and temperature will be analysed to see how it can affect the degradation of the insulation system.

The result of offline measurements show that phase R has the worst condition, phase S has the most significant deterioration, and phase T has the best condition and stability in deterioration.

In addition, partial discharge measurement indicates that the insulation has been undergoing delamination of the tape layer due to significant changes in vibration values during the operation of the machine. The result of online measurements show phase S has the most significant changes in current and power dissipation compared to other phases due to increment of operation time and load."

"The devices described in “Advanced MOS-Gated Thyristor Concepts” are utilized in microelectronics production equipment, in power transmission equipment, and for very high power motor control in electric trains, steel-mills, etc. Advanced concepts that enable improving the performance of power thyristors are discussed here, along with devices with blocking voltage capabilities of 5,000-V, 10,000-V and 15,000-V. Throughout the book, analytical models are generated to allow a simple analysis of the structures and to obtain insight into the underlying physics. The results of two-dimensional simulations are provided to corroborate the analytical models and give greater insight into the device operation."

"Banyak komponen tenaga listrik yang sedang beroperasi, seperti transformator dan circuit breaker, telah mengalami penuaan. Hal ini dapat mengakibatkan gangguan pada sistem transmisi tenaga listrik. Penuaan pada komponen ini meningkatkan aging failure rate yang juga berimplikasi pada meningkatnya probabilitas power outage serta kerugian biaya. Pemeliharaan pada komponen tua dapat menjadi tidak layak untuk dilakukan karena masalah finansial, sehingga penggantian komponen dapat lebih pantas untuk dilakukan. Dalam penelitian ini, keputusan penggantian diambil dengan membandingkan jumlah investasi dan kerugian dari gangguan penyaluran tenaga listrik. Biaya kerugian diperoleh dengan mengevaluasi reliabilitas dari sistem tenaga listrik berdasarkan pada probabilitas dan frekuensi power outage. Setiap komponen tenaga listrik pada sistem direpresentasikan dengan Markov state model, dimana karakteristik aging state setiap tipe komponen diperoleh dari hasil evaluasi data condition monitoring. Berdasarkan data yang digunakan pada penelitian ini, didapatkan bahwa penggantian terhadap komponen-komponen tenaga listrik, seperti transformer, harus dilakukan ketika memasuki umur 46 tahun, dan hal ini sesuai dengan umur operasional standar, yaitu sekitar 40 tahun.

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Many existing operating electric power equipment, including transformers and circuit breakers, have aged which may result interruption into electric power transmission. Aging equipment has increasing aging failure rate which also implicates to the rising number of system unavailability and its interruption cost. Since aging equipment tends to be impractical for maintenance due to economical constraint, a replacement is needed.

In this study, a replacement decision was made by comparing the interruption and investment cost. The interruption cost was obtained by evaluating the power system reliability based on outage probability and frequency. In order to perform this reliability evaluation, each equipment in the system was represented into Markov state model, where the aging state characteristic was obtained based on condition monitoring data assessment.

As based on the data given in this study, it was found that electric equipment, such as transformers, needs replacement at the age of 46 years which complies to the standard operational period of 40 years."

"Telah dibangun sistem pengendali syringe pump dengan rentang debit 3.2 mL⁄h-202.35 mL⁄h dan high voltage power supply dengan rentang tegangan 0-30 kV untuk sistem electrospinning. Sistem penggerak piston syringe menggunakan linear actuator yang dibangun dari ball screw 1510 dengan penggerak stepper motor. Untuk meningkatkan daya dorong piston syringe, kecepatan stepper motor direduksi dengan gearbox rasio 100:1. Pengaturan debit setiap syringe pump diatur dengan pulsa clock yang diberikan ke driver motor yang frekuensinya dapat diatur dengan persamaan frekuensi versus debit sebesar y=3.9815e^(-5) x-0.0026712. Modul tegangan tinggi AHV24V30KV1MAW dari Analog Technologies membutuhkan suplai tegangan 24 V/2 A yang dapat mengeluarkan output 0-30 kV proporsional dengan input tegangan control 0-5 V. Sistem pengendalian tegangan tinggi digunakan dua metode yaitu metode otomatis dan manual. Tegangan tinggi dan syringe pump digunakan untuk menghasilkan nanofiber menggunakan larutan polimer polyvinyl alcohol (PVA) 15wt%. Proses pengeluaran PVA dengan debit 3.2 mL/h dan tegangan tinggi minimal 10 kV dapat menghasilkan taylor cone dan tumpukan serat di collector.

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A syringe pump control system has been built with a flow rate range of 3.2-202.35 mL/h and a high voltage power supply with a voltage range of 0-30 kV for electrospinning system. Piston of the syringe is driven by a linear actuator built from a 1510 ball screw connected by a stepper motor. To increase the thrust of the syringe piston, the speed of the stepper motor is reduced by a 100:1 ratio gearbox. The flow rate setting of each syringe pump is regulated by clock pulses given to the motor driver whose frequency can be adjusted by the equation of frequency versus discharge of y=3.9815e^(-5) x-0.0026712. The high-voltage module AHV24V30KV1MAW from Analog Technologies requires a 24 V/2 A supply voltage that can output 0-30 kV proportional to the 0 -5 V control voltage input. The high-voltage control system uses two methods, namely automatic and manual methods. High voltage and a syringe pump were used to produce nanofibers using a 15wt% polyvinyl alcohol (PVA) polymer solution. PVA solution is discharged from the syringe with a flow rate of 3.2 mL/h and a high voltage at least 10 kV can produce Taylor cones and piles of fiber in the collector."