Alafia, Nurizza Salsa and Drs.Ir. Moch. Dhofir, M.T. and Dr.Rini Nur Hasanah., S.T.M.Sc.IPM. (2022) Analisis Neutral Grounding Resistors Mengatasi Hubung Singkat Satu Fasa ke Tanah Pada Generator GT 1.1 PT. Indonesia Power Grati POMU. Sarjana thesis, Universitas Brawijaya.
Abstract
Generator menjadi salah satu komponen penting dalam sistem pembangkitan. Sehingga diperlukan sistem proteksi yang dapat menjaga generator dari gangguan pentanahan. Saat terdapat gangguan hubung singkat satu fasa ke tanah, sistem pentanahan titik netral akan membatasi arus gangguan dengan mengalirkan arus gangguan ke tanah. Stabilitas sistem kelistrikan dapat terganggu akibat adanya gangguan hubung singkat. Pembangkit listrik memiliki konfigurasi sistem yang antar komponennya saling terhubung untuk dapat menghasilkan energi listrik. Listrik tersebut dibangkitkan oleh generator secara kontinyu, sehingga diperlukan sistem pentanahan yang handal agar sistem terjaga. Penggunaan NGR pada pentanahan akan rentan mengalami kegagalan karena korosi, vibrasi, petir, human error, dan osilasi pada sistem tenaga frekuensi tinggi. Namun, apabila kegagalan NGR tidak terdeteksi akan menyebabkan kerusakan pada perlatan sistem tenaga karena risiko pentanahan langsung (solid grounding). Generator dengan pentanahan langsung memiliki nilai arus gangguan yang sangat tinggi. Arus gangguan yang terlalu tinggi dapat membahayakan generator karena dapat melelehkan seluruh tembaga pada stator. Maka dari itu diperlukan adanya pentanahan dengan menambahkan impedansi pada generator. Pada penelitian ini dilakukan perhitungan dan simulasi running short circuit menggunakan ETAP 12.6 pada pentanahan titik netral generator menggunakan NGR. Penggunaan metode pentanahan NGR, arus gangguan hubung singkat satu fasa ke tanah dapat dikurangi dengan menentukan nilai NGR agar arus gangguan tidak melebihi batas aman pentanahan yaitu 25% dari arus gangguan tiga fasa ke tanah. Nilai NGR yang digunakan merupakan NGR tahanan rendah sesuai dengan yang diterapkan pada PT. Indonesia Power Grati POMU. Sebagai referensi, perhitungan dengan NGR tahanan tinggi juga dilakukan untuk mengetahui perbandingan nilai arus gangguan yang terjadi. Dari hasil penelitian didapatkan hasil bahwa pentanahan titik netral generator menggunakan NGR mampu mengurangi nilai arus gangguan satu fasa ke tanah. Dimana arus gangguan satu fasa ke tanah yang muncul apabila menggunakan NGR tidak lebih dari nilai batas aman arus gangguan generator.
English Abstract
Generator is one of the important components in the generation system. So we need a protection system that can keep the generator from grounding disturbances. When there is a single phase short circuit to ground, the neutral point grounding system will limit the current by passing the fault current to ground. The stability of the electrical system can be disrupted due to a short circuit. Power plants have a system configuration in which the components are interconnected to produce electrical energy. The electricity is generated by a generator continuously, so a reliable grounding system is needed so that the system is maintained. The use of NGR in grounding will be prone to failure due to corrosion, vibration, lightning, human error, and oscillation in high frequency power systems. However, if the NGR failure is not detected it will cause damage to the power system equipment due to the risk of direct grounding (solid grounding). Generators with direct grounding have very high fault current values. Fault currents that are too high can harm the generator because it can melt all the copper in the stator. Therefore it is necessary to ground it by adding impedance to the generator. In this study, calculations and simulations of running short circuits were performed using ETAP 12.6 at the generator neutral point grounding using NGR. Using the NGR grounding method, the single phase short circuit fault current to ground can be reduced by determining the NGR value so that the fault current does not exceed the safe ground limit, which is 25% of the three phase fault current to ground. The NGR value used is a low resistance NGR in accordance with that applied to PT. Indonesia Power Grati POMU. As a reference, calculations with high resistance NGR are also carried out to compare the value of the fault current that occurs. From the results of the study, it was found that the generator neutral point grounding using NGR was able to reduce the value of the single phase fault current to ground. Where the single phase fault current to ground that appears when using the NGR is not more than the safe limit value for the generator fault current.
Other obstract
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| Item Type: | Thesis (Sarjana) |
|---|---|
| Identification Number: | 0522070074 |
| Uncontrolled Keywords: | Kata Kunci : Generator, Neutral Grounding Resistors (NGR), solid grounding |
| Subjects: | 600 Technology (Applied sciences) > 621 Applied physics > 621.3 Electrical, magnetic, optical, communications, computer engineering; electronics, lighting > 621.38 Electronics, communications engineering > 621.381 Electronics |
| Divisions: | Fakultas Teknik > Teknik Elektro |
| Depositing User: | yulia Chasanah |
| Date Deposited: | 27 May 2022 03:07 |
| Last Modified: | 11 Dec 2023 03:59 |
| URI: | http://repository.ub.ac.id/id/eprint/190760 |
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