73 research outputs found

    Artificial Neural Network Application for Thermal Image Based Condition Monitoring of Zinc Oxide Surge Arresters

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    Manual analysis of thermal image for detecting defects and classifying of condition of surge arrester take a long time. Artificial neural network is good tool for predict and classify data. This study applied neural network for classify the degree of degradation of surge arrester. Thermal image as input of neural network was segmented using Otsu’s segmentation and histogram method to get features of thermal image. Leakage current as a target of supervise neural network was extracted and applied Fast Fourier Transform to get third harmonic of resistive leakage current. The classification results meet satisfaction with error about 3%

    EVALUASI SISTEM PENTANAHAN GARDU INDUK PAYAKUMBUH 275KV TERHADAP TEGANGAN SENTUH DAN LANGKAH SERTA GPR MENGGUNAKAN SOFTWARE CYMGRID

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    Sistem pentanahan pada gardu induk memainkan peran penting dalam melindungi peralatan listrik dan mengalirkan arus hubung singkat saat terjadi gangguan. Umumnya, sistem pentanahan gardu induk menggunakan kombinasi grid dan batang pentanahan (rod) yang ditanam dalam tanah. Penelitian ini fokus pada sistem pentanahan Gardu Induk 275 kV di Payakumbuh, dengan simulasi menggunakan perangkat lunak CYMGrd sesuai standar IEEE 80/2000. Hasil analisis menunjukkan bahwa sistem pentanahan ini aman, dengan jumlah elemen konduktor sebanyak 415 batang. Tegangan sentuh dan tegangan langkah pada sistem ini berada di bawah batas yang diizinkan. Selain itu, tahanan pentanahannya juga memenuhi rekomendasi IEEE. Melalui modifikasi jumlah dan geometri konduktor, model ketiga terbukti menjadi pilihan terbaik dari segi ekonomis, dengan hanya 279 batang konduktor tetapi tetap memenuhi standar keselamatan

    Analisa Kinerja Automatic Voltage Regulator Dalam Domain Waktu Menggunakan Metoda Ziegler-Nichols Dengan Pendekatan First Order Plus Dead Time

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    Electric power systems produce power that can be used for various purposes. The distribution of electrical power and its relationship to the voltage and current generated by the generator. Voltage can change with changes in load. The change of voltage is undesirable due to it can cause disturbances to the power system. A device called Automatic Voltage Regulator (AVR) is used to maintain the voltage stable. This AVR is equipped with a control system to get the voltage stability following the specified criteria. In this study, the Ziegler -Nichols (Z-N) method is used with the First Order Plus Dead Time (FOPDT) approach. FOPDT is used for AVR control based on frequency response and transfer function methods. AVR used is direct current type AVR. The design that fulfils the criteria for controlling the voltage transfer response of direct current type AVR systems is the Proportional Integral Differential (PID) controller. This PID is designed using the Ziegler-Nichols method with the FOPDT approach based on the transfer function method. Information on the simulation results of the direct current type of system switching AVR response is obtained where the steady-state error value is 0.0000, the rise time value is 0.6114 seconds, the peak time value is 1.4391 seconds, the peak value is 1.1492 seconds, the maximum throughput is 14.942% and time to state steady reaches value at 2.5562 seconds. The values of parameter control are k of 13.2000, L of 0.4283, T of 1.0817, Proportional constant (Kp) of 0.2296, integral time constant (Ti) of 0.8564 and differential time constant (Td) of 4.6667.Keywords : Ziegler-Nichols, Fisrt order plus dead time, Automatic voltage regulator, Transient analysis AbstrakSistem tenaga listrik menghasilkan daya yang dapat di gunakan untuk berbagai keperluan. Penyaluran daya listrik ini erta hubungan nya dengan tegangan dan arus yang di hasilkan oleh pembangkit. Tegangan dapat berubah-ubah dengan berubahnya beban. Perubahan tegangan ini tidak diinginkan karena dapat mengakibatkan gangguan pada sistem tenaga. Untuk menjaga agar tegangan tetap stabil digunakan Automatic Voltage Regulator (AVR). AVR ini dilengkapi dengan sistim pengendalian untuk mendapatkan kestabilan tegangan sesuai dengan kriteria yang di tetapkan. Pada penelitian ini digunakan metoda Ziegler -Nichols (Z-N) dengan pendekatan First Order Plus Dead Time (FOPDT) berdasarkan tanggapan frekuensi dan metoda fungsi alih sebagai metoda pengendali AVR dan AVR yang digunakan adalah AVR tipe arus searah.Pengendali yang memenuhi kriteria rancangan untuk pengendalian tanggapan peralihan tegangan sistem AVR tipe arus searah adalah pengendali Proporsional Integral Diferensial (PID). Pengendali Proporsional Integral Diferensial (PID) ini dirancang dengan menggunakan metoda Ziegler-Nichols dengan pendekatan First Order Plus Dead Time (FOPDT) berdasarkan metoda fungsi alih. Informasi hasil simulasi tanggapan peralihan sistem AVR tipe arus searah yang diperoleh dimana nilai kesalahan keadaan mantap sebesar 0.0000, nilai waktu naik sebesar 0.6114 detik, nilai waktu puncak sebesar 1.4391 detik, nilai puncak sebesar 1.1492 detik, nilai lewatan maksimum sebesar 14.942 % dan nilai waktu keadaan mantap sebesar 2.5562 detik. Untuk nilai parameter  pengendali yang digunakan adalah k sebesar 13.2000, L sebesar 0.4283, T sebesar 1.0817, konstanta Proporsional (Kp) sebesar 0.2296, konstanta waktu integral (Ti)  sebesar 0.8564 dan konstanta waktu diferensial (Td) sebesar 4.6667.Kata Kunci :Ziegler-Nichols, Fisrt order plus dead time, Automatic voltage regulator, Analis peraliha

    Optimal Sizing of Micro Hydropower to Improve Hybrid Renewable Power System

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    This paper presents an analysis of optimal micro hydropower (MH) capacity of hybrid systems to improve renewable energy based power systems. The electricity system was designed by considering river water flow data and solar radiation data at the research location, Andalas University. Optimal results obtained for the configuration of the Grid, MH, and PV with a head height of 30 m and a flow rate of 800 L/s with the lowest COE value of $ 0.065. As an optimal sizing system has been able to increase the composition of renewable energy generation in the Unand electrical network. The renewable energy fraction has increased from 26.4% to 36.5%. Therefore, determining the optimal capacity will increase the use of renewable energy generation. Conversely, an increase in electricity supply from renewable energy plants will reduce electricity consumption from the PLN grid. The latest excess power generation at a low load can be sold to the PLN gri

    Feasibility Study of Rooftop Grid Connected PV System for Peak Load Reduction

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    This paper presented the economic feasibility analysis of grid-connected photovoltaic on the roof of building, to reduce peak electrical demand. The Engineering Faculty electrical system is used as case study of PV system economic feasibility. The economic calculation assumptions used are: electricity tariff IDR 1114.74 per kWh based on electricity tariff for medium voltage load, estimated annual module degradation 0.5% and the life expectancy of the solar panels 25 years. The interest rate using of Bank Indonesia (BI) rate for 2018 i.e. 4.25% and inflation rate 3% also considered. The initial investment required to build 117.5 kWp PV system is IDR 2,413 million. The operational and maintenance costs are estimated 1% of initial investment per year. The result of cash flow rate shows that a positive NPV is achievable and payback period less then solar panels life expectancy. The simple payback period is 11 years and discounted payback period calculated by consider multiple parameters to be 14 years. The result of economic analysis using current rate value indicate that the project is profitable

    Sistem Pengatur Tegangan Otomatis : Analisa Peralihan Dengan Pengendali Tunggal Dan Kaskade

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    This journal describes the design and analysis of the response of a single controller and cascade direct current type of Automatic Voltage Regulator (AVR) system. The direct current AVR system is represented form of a transfer function. For single and cascade controllers, it is designed using a parallel architecture using MATLAB software with predetermined design criteria. The types of controllers used consist of Proportional Differential (PD), Proportional Integral (PI), Proportional Integral Differential (PID), Proportional Differential with First Order Filters in the Differential Section (PDF) and Proportional Integral Differentials with First Order Filters in the Differential Section(PIDF). For the transition analysis, the observed parameters consist of rise time, peak time, steady state time, maximum pass value and peak value. The results of the analysis show that the controllers that meet the design criteria are Proportional Differential (PD) controllers and Proportional Differential controllers with First Order Filters in Differential Sections (PDF) for single controllers and cascade controllers. For a single controller, the value of the Proportional constant (Kp) is 0.6280 and the value of the Differential constant (KD) is 0.1710 for the Proportional Differential (PD) controller. Proportional constant value (Kp) is 0.6130, Differential constant value (KD) is 0.1710 and filter constant value (Tf) is 0.0009 for Proportional Differential controller with First Order Filter in Differential Section (PDF). Cascade controllers and Proportional Differential (PD) controllers, the Proportional constant (Kp) is 1.7300 and the Differential constant (KD) is 0.0242 for the inner circle (C2). Outer ring controller (C1), the proportional constant (Kp) is 179,000 and the Differential constant (KD) is 2.4600. Cascade controllers and Proportional Differential controller types with First Order Filters in the Differential Section (PDF), the Proportional constant (Kp) value is 1.5900, the Differential constant (KD) value is 0.0246, the filter constant value (Tf) is 0.0018 for the inner circumference (C2 ). For the outer ring controller (C1), the Proportional constant (Kp) value is 134,0000, the Differential constant (KD) value is 2.2900 and the filter constant value (Tf) is 0.00008

    Pemodelan Dan Simulasi Sistem Pengontrolan Tegangan Dan Frekuensi Generator Induksi Tipe Doubly Fed Aplikasi Pada Pembangkit Listrik Tenaga Angin

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    Simulasi ini menghasilkan suatu keluaran berupa tegangan, arus, daya, dan kecepatan angin per detik. Hasil dari keluaran simulasi ini dapat digunakan untuk menganalisa karakteristik suatu turbin angin yang sedang dirancang atuapun turbin angin yang akan dipasang di suatu daerah yang telah diketahui kecepatan angin rata-ratanya. Masing-masing bagian dibangun dalam bentuk blok-blok tersendiri dan data-data dari bagian tersebut dapat dimasukkan secara terpisah dari sistem. Persamaan rotor turbin yang diperoleh dari literatur dikonversikan kedalam bahasa matlab/simulink sehingga diperoleh satu blok rotor turbin dimana data-datanya dimasukan melalui dialog box yang lebih dikenal dengan grafik user interface (GUI) yang merupakan fasilitas dari matlab simulink.Demikian juga untuk bagian-bagian yang lain seperti : transmisi mekanik (gear box), generator, pengaturan tegangan dan frequensi, beban dan kapasitor. Setelah semua blok terbentuk dan telah diuji sesuai dengan karakteristik masing-masing, maka selanjutnya blok-blok tersebut dirangkai sesuai dengan turbin angin sesungguhnya dan simulasi turbin angin siap dijalankan. Hasil simulasi menunjukan tegangan yang dihasilkan sesusai dengan yang diharapkan yang berarti pengaturan tegangan frekuensi bekerja dengan bai

    Karakteristik Medan Listrik-Dekat Petir Positive Cloud to Ground

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    This study was conducted on 19 electric field data near positive lightning cloud to ground (+CG). The electric field change of +CG lightning consist of preliminary breakdown (PB) and return stroke (RS). The analysis conducted in this research are: PB/RS ratio, PB-RS separation, pre-return stroke duration, pulse train duration, and individual pulse duration. Furthermore, the relationship between +CG lightning and cloud image satellite was observed the average value of PB/RS ratio, PB-RS separation, prereturn stroke duration, pulse train duration and individual pulse duration were 13,89%, 91,53 ms, 102,23 ms, 1,20 ms,150,31 μs, respectively

    Peningkatan Faktor Penuaan Arester Tanpa Sela Isolasi Polymer Akibat Kontaminan Kalsium Karbonat

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    Gapless arester leakage current can be used as an indicator to determine the aging level of the arester. Leakage current is influenced by contaminants present in the arester insulation. This paper analyzes the effect of contamination on arester leakage currents as an indicator of arester aging. Contaminants used are calcium carbonate plus kaolin dissolved into water, to determine the level of calcium carbonate contaminants, the ESDD (Equivalent Salt Deposit Density) method is used. Contaminated aresters are measured as leakage currents flowing to the block elements and to the arester insulation. Based on experiments that have been carried out, the increase in leakage current of the arester on the block element that increases the leakage current to the level of light, medium and heavy contamination rises by an average of 17.5% for the voltage of all test voltages. While at low and moderate contamination the leakage current that occurs in the polymer arester insulation does not significantly change, the leakage current generated is linear with the level of contaminants in the arester body. It can clearly be concluded that the effect of contamination is very significant in changes in leakage currents. Keywords : Gapless arester, Leakage current, Kontamination, Aging, Abstrak Arus bocor arester tanpa sela dapat digunakan sebagai indikator untuk menentukan tingkat penuaan arester. Arus bocor dipengaruhi oleh kontaminan yang ada pada isolasi arester. Paper ini menganalisa pengaruh kontaminasi terhadap arus bocor arester sebagi indikator penuaan arester. Kontaminan yang digunakan adalah kalsium karbonat di tambah kaolin yang di larutkan kedalam air, untuk menentukan tingkat kontaminan kalsium karbonat maka digunakan metode ESDD (Equivalent Salt Deposit Density). Arester yang sudah berkontaminasi diukur arus bocor yang mengalir pada elemen blok dan pada isolasi arester. Berdasarkan percobaan yang telah dilakukan, kenaikan arus bocor arester pada elemen blok bahwa kenaikan arus bocor untuk tingkat kontaminasi ringan,sedang dan berat naik rata-rata 17.5 % untuk semua tegangan uji. Sementara pada kontaminasi rendah dan sedang arus bocor yang terjadi pada isolasi polimer arester tidak. singnifikan perubahannya,Arus bocor yang dihasilkan linier dengan tingkat kontaminan pada badan arester. Secara jelas dapat disimpulkan bahwa pengaruh kontaminasi sangat signifikan dalam perubahan arus bocor. Kata Kunci : Arester tanpa sela, Arus bocor, Kontaminasi, Penuaan
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