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Abstrak :
This book focuses on oil-paper insulation included in power transformers, especially for EHV and UHV transformers. The importance on insulation ever increased due to a growing voltage rating of transformers. Within the last decades, although research on the transformer insulation and diagnosis methods has advanced a lot, the insulation of HV transformers remained more or less unchanged. The book is divided into five chapters; the first and second chapters explain the basics of oil insulation, while the third chapter focuses on paper insulation. The final two chapters deal with the methods and outcome of testing both techniques. The primary target audience for this book is graduate students and power system engineers.

Abstrak :
Transformator adalah suatu alat listrik yang berfungsi sebagai pengubah tegangan, yakni mengubah tegangan rendah menjadi tegangan tinggi, atau sebaliknya, dengan frekuensi tetap. Dalam transformator terdapat inti besi dengan kumparan serta minyak transformator yang menjadi isolator sekaligus pendingin sistem transformator tersebut. Namun seiring beroperasinya transformator, kualitas dari minyak transformator ini akan mengalami penurunan yang mengakibatkan kualitas isolator dan juga sifat pendingin dari minyak transformator tersebut akan mengalami penurunan pula. Dalam kondisi seperti ini, kapasitansi dapat timbul di dalam transformator akibat adanya beda potensial dalam transformator di antara inti transformator dengan tangki transformator. Dalam skripsi ini akan dibahas bagaimana pengujian minyak transformator dengan metode kapasitansi dan bagaimana kaitannya dengan karakteristik minyak transformator. ...... The transformer is an electrical device that functions as a voltage converter, which is change the low voltage into high voltage, or vice versa, with a fixed frequency. Contained within the iron core transformer with the coil and transformer oil which becomes an insulator once the transformer cooling system. But with the operation of the transformer, the quality of the transformer oil will decline resulting in quality insulators and cooling properties of the transformer oil will decline as well. Under these conditions, the capacitance can arise in the transformer due to the potential difference between the transformer core transformer with the transformer tank. In this paper will discuss how to test transformer oil by capacitance method and how it relates to the characteristics of transformer oil.

Abstrak :
[Skripsi ini membahas tentang kinerja current limiting reactor (CLR) dalam hal membatasi arus saat terjadi tegangan percikan di transformer rectifier (TR) pada electrostatic precipitator (EP). Objek yang dijadikan pada penulisan karya tulis ini adalah EP unit 7 UBP.Suralaya. Penelitian dilakukan dengan melakukan pengukuran nilai input dan output dari TR yang kemudian data tersebut diolah untuk kemudian dibandingkan antara hasil perhitungan dengan data pengamatan, selain itu dilakukan pula pengamatan kinerja CLR jika dilihat dari tata letak TR yang digunakan. Dari hasil penelitian, diketahui bahwa kinerja dari CLR yang digunakan pada EP unit 7 UBP.Suralaya masih baik. Hal ini diketahui dari nilai jatuh tegangan yang didapat pada sisi primer TR masih tidak melenceng terlalu jauh dari nilai rating peralatan yang digunakan. Sehingga dapat dikatakan tidak terlalu berdampak terhadap pengurangan efisiensi penangkapan debu EP. Diketahui pula bahwa jumlah tegangan percikan dipengaruhi oleh tata letak dari TR yang digunakan. Semakin TR tersebut berdekatan dengan kontak terhadap debu, maka semakin besar kemungkinan terjadinya tegangan percikan dan semakin besar pula kemungkinan jumlah tegangan percikan yang terjadi sehingga memungkinkan untuk CLR melakukan kerja yang lebih berat. ...... This thesis discusses the performance of current limiting reactor (CLR) in terms of limiting current occurs when the voltage spark in rectifier transformers (TR) on the electrostatic precipitator (EP). Objects that are used in writing this paper is that the EP unit 7 UBP.Suralaya. The study was conducted by measuring the input and output values ​​of TR and then the data is processed and then compared the results of calculations with observational data, but it also made ​​observations of the performance of CLR when viewed from TR layout used. From the research, it is known that the performance of the CLR is used on the EP unit 7 UBP.Suralaya still good. It is known from the voltage drop value obtained on the primary side of the TR is still not too far from the rating value of used equipment. So it can be said has little impact on the reduction of EP dust capture efficiency. It found that the number of spark voltage is affected by the layout of the TR is used. The TR is getting close to the contact of the dust, the greater the likelihood of the spark voltage and the greater the likelihood that the amount of voltage spark occurs making it possible for the CLR do the heavier work.;This thesis discusses the performance of current limiting reactor (CLR) in terms of limiting current occurs when the voltage spark in rectifier transformers (TR) on the electrostatic precipitator (EP). Objects that are used in writing this paper is that the EP unit 7 UBP.Suralaya. The study was conducted by measuring the input and output values of TR and then the data is processed and then compared the results of calculations with observational data, but it also made observations of the performance of CLR when viewed from TR layout used. From the research, it is known that the performance of the CLR is used on the EP unit 7 UBP.Suralaya still good. It is known from the voltage drop value obtained on the primary side of the TR is still not too far from the rating value of used equipment. So it can be said has little impact on the reduction of EP dust capture efficiency. It found that the number of spark voltage is affected by the layout of the TR is used. The TR is getting close to the contact of the dust, the greater the likelihood of the spark voltage and the greater the likelihood that the amount of voltage spark occurs making it possible for the CLR do the heavier work., This thesis discusses the performance of current limiting reactor (CLR) in terms of limiting current occurs when the voltage spark in rectifier transformers (TR) on the electrostatic precipitator (EP). Objects that are used in writing this paper is that the EP unit 7 UBP.Suralaya. The study was conducted by measuring the input and output values of TR and then the data is processed and then compared the results of calculations with observational data, but it also made observations of the performance of CLR when viewed from TR layout used. From the research, it is known that the performance of the CLR is used on the EP unit 7 UBP.Suralaya still good. It is known from the voltage drop value obtained on the primary side of the TR is still not too far from the rating value of used equipment. So it can be said has little impact on the reduction of EP dust capture efficiency. It found that the number of spark voltage is affected by the layout of the TR is used. The TR is getting close to the contact of the dust, the greater the likelihood of the spark voltage and the greater the likelihood that the amount of voltage spark occurs making it possible for the CLR do the heavier work]

Abstrak :
Text clustering adalah teknik pengelompokan teks sehingga teks di dalam kelompok yang sama memiliki tingkat similaritas yang lebih tinggi satu sama lain dibandingkan dengan teks pada kelompok yang berbeda. Proses pengelompokkan teks secara manual membutuhkan waktu dan sumber daya yang banyak sehingga digunakan machine learning untuk melakukan pengelompokan secara otomatis. Representasi dari teks perlu diekstraksi sebelum dimasukkan ke dalam model machine learning. Metode yang umumnya digunakan untuk mengekstraksi representasi data teks adalah TFIDF. Namun, metode TFIDF memiliki kekurangan yaitu tidak memperhatikan posisi dan konteks penggunaan kata. Model BERT adalah model yang dapat menghasilkan representasi kata yang bergantung pada posisi dan konteks penggunaan suatu kata dalam kalimat. Penelitian ini menganalisis kinerja model BERT sebagai metode representasi data teks dengan membandingkan model BERT dengan TFIDF. Selain itu, penelitian ini juga mengimplementasikan dan membandingkan kinerja metode ekstraksi dan normalisasi fitur yang berbeda pada representasi teks yang dihasilkan model BERT. Metode ekstraksi fitur yang digunakan adalah max dan mean pooling. Sementara itu, metode normalisasi fitur yang digunakan adalah identity, layer, standard, dan min-max normalization. Representasi teks yang diperoleh dimasukkan ke dalam 4 algoritma clustering berbeda, yaitu k-means clustering, eigenspace-based fuzzy c-means, deep embedded clustering, dan improved deep embedded clustering. Kinerja representasi teks dievaluasi dengan menggunakan metrik clustering accuracy, normalized mutual information, dan adjusted rand index. Hasil simulasi menunjukkan representasi data teks yang dihasilkan model BERT mampu mengungguli representasi yang dihasilkan TFIDF pada 28 dari 36 metrik. Selain itu, implementasi ekstraksi dan normalisasi fitur yang berbeda pada model BERT memberikan kinerja yang berbeda-beda dan perlu disesuaikan dengan algoritma yang digunakan. ......Text clustering is a task of grouping a set of texts in a way such that text in the same group will be more similar toward each other than to those from different group. The process of grouping text manually requires significant amount of time and labor. Therefore, automation utilizing machine learning is necessary. Text representation needs to be extracted to become the input for machine learning models. The common method used to represent textual data is TFIDF. However, TFIDF cannot consider the position and context of a word in a sentence. BERT model has the capability to produce text representation that incorporate position and context of a word in a sentence. This research analyzed the performance of BERT model as a text representation method by comparing it with TFIDF. Moreover, various feature extraction and normalization methods are also applied in text representation from BERT model. Feature extraction methods used are max and mean pooling. On the other hand, feature normalization methods used are identity, layer, standard, and min-max normalization. Text representation obtained become an input for 4 clustering algorithms, k-means clustering, eigenspace-based fuzzy c-means, deep embedded clustering, and improved deep embedded clustering. Performance of text representations in text clustering are evaluated utilizing clustering accuracy, normalized mutual information, and adjusted rand index. Simulation results showed that text representation obtained from BERT model outperforms representation from TFIDF in 28 out of 36 metrics. Furthermore, different feature extraction and normalization produced varied performances. The usage of these feature extraction and normalization must be altered depending on the text clustering algorithm used.

Abstrak :
Banyaknya aplikasi beban nonlinier pada sistem distribusi tenaga listrik dimana salah satunya komponen penting yang digunakan pada sistem tenaga listrik adalah transformator daya telah membuat arus sistem menjadi sangat terdistorsi dengan persentase kandungan harmonik arus THD (Total Harmonic Distortion) yang sangat tinggi. Dari hasil pengukuran di PT. Indocement Tunggal Prakarsa, Tbk diketahui bahwa pada salah satu transformator daya yaitu pada transformator 3 terdapat harmonik dengan persentase THD arus sebesar 26.3 % yang melebihi batas IEEE 519-1992 yang diijinkan yaitu 15 %, harmonik yang dominan adalah harmonik ke-3, ke-5 dan ke-7. Meski demikian pengaruh distorsi harmonik pada komponen secara umum adalah penurunan kinerja dan bahkan kerusakan suatu alat.

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Nonlinear load applications on electric power distribution system in which one of the important components used in electrical power systems are power transformers making the current system highly distorted caused by high the percentage THD current harmonic content (total harmonic distortion). Results of measurements in PT. Indocement Tunggal Prakarsa, Tbk is discovered in one of power transformer power labeled as transformer 3 has percentage of harmonic current THD in amount of 26.3% that exceeds the IEEE 519-1992 limits standards which is only allow 15% of the dominant harmonic on the 3rd harmonic, the 5 and to-7. Yet the influence of harmonic distortion on the general component is decreased performance and even damage a tool. Therefore, this writing will be explained by result of observation on harmonic distortion effect at transformers performance which is one of the electric power system fundamental components. Power Transformers performance can be determined through Power losses parameter that happened on transformers when operating with non linear and linear Load. Harmonic Distortion cause Power losses on transformers which is proportionally increase to high harmonic components current in loads current.

Abstrak :
Buku yang berjudul "Handbook for electronic engineers and technicians" ini ditulis oleh Harry E. Thomas. Buku ini merupakan sebuah buku panduan mengenai elektronik, diperuntukkan bagi para teknisi.

Abstrak :
Transformator merupakan mesin listrik stastis yang berperan penting dalam sistem distribusi tenaga listrik yang berfungsi mengatur besar tegangan pada masukan maupun keluaran dari sistem distribusi. Kinerja transformator dipengaruhi oleh kondisi beberapa komponen dasarnya salah satunya adalah isolator minyak yang berfungsi untuk memisahkan dua atau lebih konduktor yang berdekatan untuk mencegah adanya kebocoran arus dan juga sebagi pelindung mekanis. Selain itu minyak isolator dapat membantu dalam memprediksi kegagalan pada transformator dengan mengolah konsentrasi gas gangguan menggunakan metode Dissolved Gas Analysis, yaitu metode Total Dissolved Combustible Gas, Gas Kunci, Rasio Roger, Segitiga Duval, dan Pentagon Duval. Data konsentrasi gas diperoleh dari transformator distribusi yang digunakan pada suatu sistem listrik dalam beberapa perushaan. Melalui pengolahan data menggunakan metode-metode DGA, diperoleh bahwa metode Penatagon Duval merupakan metode paling baik dalam memprediksi kegagalan pada transformator dibandingkan metode lainnya, karena menghasilkan hasil prediksi yang tepat dan spesifik, tidak memiliki syarat yang harus dipenuhi oleh suatu data untuk dapat diolah oleh metode tersebut, dan tidak memerlukan tahap lanjutan dalam menentukkan hasil akhir prediksi.

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Transfomer is a static electrical machine that plays important role in power distribution system that serves to set input and output voltage of the system. The performance of the transformer is effected by condition of it components, one of the important components is an isolator oil that works for separate two or more conductors to prevent current leakage and also as a mechanical shielding. In addition, the isolator oil can be use for tools for predicting the failure in the transformer by processing fault gas with dissolved gas analysis method, such as Total Dissolved Combustable Gas, Key gas, Rogers Ratio, Duvals Triangel and Duvals Pentagon. The gas concentration is obtained from distribution transformers that used in electrical system in several firms. By processing fault gas cocentration with DGA methods, it can be concluded that Duvals Pentagon Method is the most excelent method for predicting the failure in transformers since the method predicting results correctly and more specific interm of failure, it doesnt have a condition that must be fulfilled by the data before using this method, and also does not require an advance step in defining prediction result.