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All Journal International Journal of Electrical and Computer Engineering Jurnal ELTIKOM : Jurnal Teknik Elektro, Teknologi Informasi dan Komputer Jurnal Teknologi Elekterika Jurnal Teknik Mesin Sinergi Indonesian Journal of Multidisciplinary Scientific Studies
Ahmad Gaffar
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Aerospace Engineering Computer Science & IT Control & Systems Engineering Economics, Econometrics & Finance Education Electrical & Electronics Engineering Energy Engineering Mathematics Mechanical Engineering Social Sciences Other

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ANALISIS GANGGUAN HUBUNG SINGKAT JARINGAN DISTRIBUSI TEGANGAN MENENGAH 20 KV AREA KENDARI Gaffar, Ahmad
Jurnal Teknologi Elekterika Vol 12, No 1 (2015): Edisi Cetak (Januari 2015,Tahun 12, No 1)
Publisher : Politeknik Negeri Ujung Pandang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (835.606 KB) | DOI: 10.31963/elekterika.v12i1.1497

Abstract

Penelitian ini bertujuan  untuk mengetahui penyebab dari Malfunction-nya Directional Ground Fault Relay yang berfungsi untuk memproteksi jaringan Express Feeder 2 yang menghubungkan antara GI Puwatu dan PLTD Wua-wua. Kondisi sistem yang awalnya berjalan secara normal, secara mendadak berubah menjadi Black Out. Sistem mengalami black out, beberapa saat setelah gangguan muncul pada Express Feeder (2) Gardu Induk (GI) Puwatu – Pembangkit Listrik Tenaga Diesel (PLTD) Wua wua dan mengakibatkan under frequency. Kondisi Black Out tersebut  berlangsung cukup lama, hingga akhirnya  sistem mulai normal kembali. Untuk mencapai tujuan tersebut, pertama tama  dilakukan perhitungan Arus hubung singkat, kemudian dibandingkan dengan keadaan pada saat gangguan. Rekonstruksi gangguan juga dilakukan guna mengetahui seperti apa kondisi relay pada saat gangguan terjadi. Berdasarkan penelitian yang dilakukan maka dapat diketahui penyebab malfunction-nya Directional Ground Fault Relay, meliputi  nilai arus hubung singkatnya, lokasi dari gangguannya hingga karakteristik dari gangguan itu sendiri. Arus hubung singkat yang terjadi sebesar 171 A sdang arus setting relay sebesar 26 A;  waktu dari gangguan yang terjadi sebesar 129,048 milidetik dan nilai settingan waktu pada relay adalah sebesar 473 milidetik sehingga Relai Gangguan Tanah Berarah ( Directional Ground Fault Relay ) tidak trip disebabkan karena selang waktu dari gangguan lebih cepat dari pada waktu setting pada relai, sehingga sampai gangguan selesai terjadi, relai hanya mengalami Pick Up
FAKTOR-FAKTOR PENYEBAB TERJADINYA PERUBAHAN TEGANGAN PERMUKAAN TANAH PADA PEMBUMIAN SISTEM GRID-ROD DALAM STRUKTUR TANAH DUA LAPIS (SUATU ANALISA KASUS) Tadjuddin Tadjuddin; Ahmad Gaffar; Bakhtiar Bakhtiar
Jurnal Teknik Mesin Sinergi Vol 11, No 2 (2013): Oktober 2013
Publisher : Politeknik Negeri Ujung Pandang

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (288.513 KB) | DOI: 10.31963/sinergi.v11i2.1106

Abstract

Penelitian ini bertujuan untuk mengetahui faktor faktor yang menjadi penyebab turun/ rendahnya nilai tegangan permukaan tanah khususnya tegangan sentuh sentuh yang timbul saat terjadi gangguan,Besarnya tegangan sentuh dipengaruhi banyak factor shingga dalam merencanakan sisatem pembumian perlu diketahui faktor yang dominan berpengaruh terhadap tegangan sentuh tersebut. Data-data yang digunakan merupakan data sekunder yang diperoleh pada P.T PLN khususnya PIKITRING SULMAPA antara lain nilai tahanan jenis tanah, ketebalan lapisan tanah bagian pertama, tegangan kerja sistem yang direncanakan. Kegiatan ini diawali dengan menghitung: Luas Daerah Pembumian, Ukuran Minimum Elektroda Pembumian, Jumlah Minimum Batang Konduktor serta seluruh panjang batang pembumian yang diperlukan untuk selanjutnya hasilnya digunakan menghitung Tegangan Sentuh. Hasil penelitian menunjukkan bahwa faktor faktor yang dominan berpengaruh terhadap rendahnya atau turunnya tegangan sentuh secara berturut turut adalah sbb: i). Perubahan jarak antara konduktor paralel(D). Semakin kecil jarak konduktor parallel maka semakin panjang elektroda grid yang dibutuhkan. Dengan semakin kecilnya nilai tahanan dari konduktor yang paralel tersebut berarti semakin memudahkan jalan arus gangguan ke tanah sehingga tegangan pada permukaan tanah menjadi semakin kecil. Hasil perhitungan menunjukkan bahwa setiap penambahan 1 meter jarak konduktor paralel (dari 3 meter sampai dengan 12 meter) menyebabkan terjadinya perubaha rata-rata tegangan sentuh sebesar 11,36 %. Untuk ρ1 = 30,4 (Ω.m) dan ρ2 = 11,3 Ω.m ii), Perbandingan tahanan jenis tanah lapisan pertama dan lapisan kedua. Dan iii) kedalaman penanaman elektroda grid. Hasil yang diperoleh, menunjukkan bahwa semakin dalam elektroda tersebut tertanam dalam tanah (dari 0,5 meter sampai dengan kedalaman 1,0 meter) tegangan sentuh semakin kecil. Namun bila kedalaman penanaman elektroda ditambah terus melibihi 1,0 meter ternyata tegangan sentuh menjadi semakin besar. Hal ini sesuai dengan hasil penelitian dalam IEEE, bahwa penanaman elektroda grid akan efektif menurunkan tegangan sentuh hanya sampai pada kedalaman 1,0 meter.
Optimal inverter-based distributed generation in ULP Way Halim considering harmonic distortion Sofyan, Sofyan; Faraby, Muhira Dzar; Akhmad, Satriani Said; Gaffar, Ahmad; Fitriati, Andi; Elviralita, Yoan; Muchtar, Akhyar
International Journal of Electrical and Computer Engineering (IJECE) Vol 13, No 6: December 2023
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijece.v13i6.pp6058-6067

Abstract

Integration of distributed generation (DG) based on the use of new renewable energy is considered to be able to increase the capability of the electric power distribution system. However, the use of inverter-based DG is not optimal, it can worsen the condition of the system, especially in terms of the spread of harmonic distortion which can damage the equipment. This is due to the inverter-based DG technology, apart from supplying electrical energy, DG also injects harmonic currents from existing semiconductor components. This research discusses optimization placement of inverter-based DG using the multi objective particle swarm optimization (MOPSO) method which was tested on the Unit Layanan Pelaksana (ULP) Way Halim 88-bus radial distribution system based on MALTAB 2020b to increase the efficiency of the electrical system by reducing losses and %THDv. The inverter-based DG placed on 24 bus points with a capacity of 690 kW can reduce losses by up to 12.74 kW or 14.96% and all %THDv values for each bus are below 5%.
Perbandingan Efisiensi Aktual Dan Spesifikasi Generator BTG II Power Plant PT. Semen Tonasa 2×35 MW Pada Berbagai Beban Aktual Usman, Usman; Multazam, Ahmad; Gaffar, Ahmad
Jurnal ELTIKOM : Jurnal Teknik Elektro, Teknologi Informasi dan Komputer Vol. 6 No. 2 (2022)
Publisher : P3M Politeknik Negeri Banjarmasin

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31961/eltikom.v6i2.554

Abstract

The efficiency of generators in a power plant decreases as running duration increases. This can also happen to the generator of the PT. Steam Power Plant. The Semen Tonasa Power Plant is also known as the Boiler Turbine Generator (BTG) Power Plant. BTG II has been operating for approximately 8 years and based on generator operation data, there has been a decrease in the power generated by the genera-tor, when viewed from the power input to the current turbine, compared to the initial operation of this plant. The aims of this study are to assess the value of the real generator efficiency and compare it to the efficiency generator based on its specifications. Data loading is required to ascertain the true value of generator efficiency, as the output power created by the generator and the input power is the power gen-erated by the turbine, which is computed using the enthalpy reduction method. According to the research, the average generator efficiency values for generator units C and D are 91.36 percent and 90.34 percent, respectively, with real average loads of 25,56 MW and 25,08 MW. In comparison to the data standards, generator unit C saw a 6.76 percent drop in efficiency, whereas generator unit D experienced a 7.76 per-cent decrease efficiency. Comparison with the data specifications for generator units C experienced a decrease in efficiency of 6,76% while generator unit D experienced a decrease in efficiency of 7,76%. The efficiency of the generator in unit C decreased 0.85% per year, and unit D was 0.97%.
Analysis of Improvement of Distribution Substation Earthing Resistance Values at PT. PLN (Persero) ULP Karebosi Usrha, Ian Maulana; Gaffar, Ahmad; Sultan, Ahmad Rizal
Jurnal Teknologi Elekterika Vol. 21 No. 2 (2024)
Publisher : Jurusan Teknik Elektro Politeknik Negeri Ujung Pandang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31963/elekterika.v21i2.5099

Abstract

The grounding system at the distribution substation is an essential component closely related to maintaining the reliability of the electrical system. In this regard, this study aims to examine the impact of applying certain grounding methods to improve grounding resistance values at the distribution substation. The research was conducted over five months, from January 15, 2024, to June 15, 2024, at the Pannampu feeder managed by ULP Karebosi. MATLAB GUI was used to theoretically calculate using the Dwight equation related to grounding resistance (Ω) and soil resistivity (Ωm). The results of this study show that the measured grounding resistance values after applying the multiple grounding rod method decreased by 52.49% for the grounding electrode of the lightning arrester GD. KPPKU, 49.45% for the grounding electrode of the transformer body and PHB-TR GD. KPPKU, and 48.94% for the grounding electrode of the lightning arrester GD. KPPDK, which had grounding resistance values of 5.43Ω, 5.44Ω, and 8.42Ω before reconfiguration.
Analysis of Main Protection Replacement of Bay Line Parepare - Suppa from Distance Relay to Line Current Differential Relay of 150 kv Parepare Substation Fattah, Darmin; Sultan, Ahmad Rizal; Gaffar, Ahmad
Jurnal Teknologi Elekterika Vol. 22 No. 1 (2025)
Publisher : Jurusan Teknik Elektro Politeknik Negeri Ujung Pandang

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Bay Line Parepare - Suppa uses relay distance as the main safety. With a short transmission line distance, a reliable protection system is needed to overcome disturbances that occur in the system. With the development of time, and also to further improve the main transmission safety, the distance relay as the main protection is replaced with LCD (Line Current Differential) with changes in SPLN T5.002: 2010 to SPLN T5.002: 2021. This study aims to characterize the impedance value, the results of the SIR (Source Impedance Ratio) process and the effect of revenue obtained in replacing the main protection of the Parepare - Suppa bay line from relay distance to LCD (Line Current Differential) relay. Based on the calculation of the impedance seen in the relay distance on the Parepare - Suppa high voltage overhead line, the results are very small (0.1286 - 0.321 ohms). The results of the analysis show that the Source Impedance Ratio (SIR) obtained on the Parepare - Suppa conductor is 4.015 Ohm, while after replacing the relay, the gain or profit obtained is Rp. 1,112,340,880, -
Design and Development of an IoT-Based Escalator Control System Using WhatsApp as a Learning Medium at Makassar Aviation Polytechnic Irfan; Andi.Muh. Kautsar Jeddawi. Bn; Andi Athaya Endra Zaki; Ahmad Gaffar
Indonesian Journal of Multidisciplinary Scientific Studies Vol 3 No 4 (2025): Edisi Juli 2025
Publisher : Lembaga Penelitian Dan Pengabdian Masyarakat (LPPM) STAI Raudhatul Akmal

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33151/ijomss.v3i4.657

Abstract

The limited practical laboratory facilities at Makassar Aviation Polytechnic, especially for the Airport Equipment course, force students to make direct visits to the airport to study equipment such as escalators. This condition not only hampers the effectiveness of learning but also adds to the cost and time burden. This research aims to design and test an Internet of Things (IoT)-based escalator control system integrated with WhatsApp application as an interactive learning media. The system is controlled through WhatsApp message commands using ESP32, which is connected to the SSR module, LCD, buzzer, and AC motor. The tool development was carried out using the Research and Development (R&D) method and tested using a black box testing approach. The test results show that all system components work optimally, and a survey involving 29 respondents showed an average effectiveness rate of 97.8%. The system proved to be easy to understand, responsive, and suitable for learning needs. Thus, this tool not only accelerates students' understanding of IoT-based automatic control systems, but also becomes an efficient solution to overcome the limitations of practicum facilities in the campus environment. This system also opens up the potential of utilizing popular communication platforms as a means of controlling engineering devices in the world of vocational education.
Co-Authors Ahamad Rizal Sultan Ahmad Multazam, Ahmad Akhmad, Satriani Said Akhyar Muchtar, Akhyar Andi Athaya Endra Zaki Andi Fitriati Andi.Muh. Kautsar Jeddawi. Bn Bakhtiar Bakhtiar Bakhtiar, Bakhtiar. Fattah, Darmin MMSI Irfan ,S. Kom Muhira Dzar Faraby, Muhira Dzar sofyan sofyan Tadjuddin Tadjuddin Usman Usman Usrha, Ian Maulana Yoan Elviralita