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<![CDATA[Analisis Pengaruh Intensitas Matahari, Suhu Permukaan & Sudut Pengarah Terhadap Kinerja Panel Surya ]]>
<![CDATA[- Suwarti]]>;
<![CDATA[- Wahyono]]>
<![CDATA[ Eksergi Vol 14, No 2 (2018): MEI 2018 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v14i2.1325
<![CDATA[Tujuan penelitian ini adalah untuk mengetahui pengaruh intensitas matahari, suhu permukaan, dan sudut pengarah terhadap daya panel surya. Pengaruh intensitas matahari didapat dengan cara perubahan waktu sehingga intensitasnya bervariasi dengan sudut tetap 90o dan suhu permukaan relatif sama, suhu permukaan didapatkan dengan cara memvariasi suhu dengan sudut pengarah tetap 90o dan intensitas relatif sama, sudut pengarah didapat dengan cara memvariasi sudut pengarah dengan intensitas dan suhunya relatif sama. Pengaruh kinerja panel surya yaitu semakin besar intensitas matahari maka arusnya semakin besar dan tegangannya cenderung tetap. Suhhu permukaan mempengaruhi performa panel surya yaitu semakin besar temperaturenya maka tegangannya semakin kecil dan arusnya cenderung tetap. Sudut pengarah mempengaruhi performa panel surya yaitu semakin mendekati tegak lurus terhadap datangnya cahaya mathari maka tegangan dan arusnya akan semakin besar. Data-data hasil pengujian kemudian diolah untuk mengetahui daya listrik maksimum yang mampu dihasilkan. Hasil tugas akhir ini menunjukkan bahwa pada intensitas matahari 1006 W/m2dengan daya terbesar yang mampu dihasilkan adalah 28,035 watt. Pada temperature permukaan 54,5oC dengan daya terbesar 28,035 watt. Pada sudut pengarah 90odaya terbesar yang dihasilkan adalah 26,7735 watt. Peforma panel surya dipengaruhi oleh intensitas matahari, temperatur permukaan, dan sudut pengarah semakin besar faktor yang mempengaruhinya daya yang dihasilkan juga semakin besar. Kata kunci : Peforma panel surya, Daya yang dihasilkan, Faktor pengaruh.]]>
<![CDATA[Rancang Bangun Motor – Generator Magnet Permanen Jenis NdFeB ]]>
<![CDATA[Budhi Prasetiyo]]>;
<![CDATA[Teguh Harijono Mulud]]>
<![CDATA[ Eksergi Vol 15, No 2 (2019): MEI 2019 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v15i2.1507
<![CDATA[Ketidaktersediaan energi listrik merupakan suatu masalah bagi masyarakat modern khususnya pengguna perangkat elektronik dengan konsumsi daya rendah. Dari permasalahan tersebut dibutuhkan suatu alat motor – generator magnet permanen jenis NdFeB untuk menghasilkan energi listrik. Sumber energi listrik berasal dari baterai 9 volt disusun seri untuk membangkitkan fluks inti besi dengan bantuan kumparan. Fluks inti besi motor impuls menghasilkan kutub magnet yang sejenis pada komponen rotor sehingga timbul gaya tolak menolak dan menyebabkan komponen rotor bergerak dan magnet rotor menginduksi kumparan stator. Metode tugas akhir yang dimulai dari tahapan pembuatan, perakitan dan pengujian seluruh komponen motor – generator. Pengujian menggunakan beban berupa lampu LED, tahanan keramik dan potensiometer. Tegangan keluaran generator yang diperoleh pada karakteristik beban nol ialah 8.83 VDC dan tegangan keluaran tertinggi sebesar 8.84 VDC dan arus 0.009 Ampere menggunakan beban potensiometer 18KOhm. Untuk mendapatkan daya keluaran yang lebih besar dengan melakukan pembuatan ulang komponen dengan ketelitian yang lebih tinggi, memvariasi jumlah magnet, merubah ukuran lilitan dan memperkecil lebar celah udara.]]>
<![CDATA[SOIL TREATMENT ARANG PADA ELEKTRODA PLAT YANG DISUSUN SECARA PARALEL UNTUK MENURUNKAN TAHANAN PEMBUMIAN ± 75% ]]>
<![CDATA[Wiwik Purwati Widyaningsih]]>;
<![CDATA[Teguh Harijono Mulud,]]>;
<![CDATA[Dhevi Saraswati]]>
<![CDATA[ Eksergi Vol 16, No 1 (2020): JANUARI 2020 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v16i1.2204
<![CDATA[Abstrak Tujuan penelitian ini adalah untuk mengetahui penurunan nilai tahanan pembumian pada elektroda plat(16x12x0,01) cm yang disusun secara horizontal dengan pengolahan tanah arang di atas dan di bawah elektroda plat dan untuk mencegah terjadinya tegangan sentuh yang dapat membuat manusia dalam bahaya. Metode pengambilan data ini adalah uji tiga titik sejajar dengan elektroda utama. Variasi dalam penanaman elektroda adalah (10, 20, 30, 40, 50, 60) cm dan tinggi arang di dalam tanah adalah (5, 10, 15, 20, 25, 30) cm. Kegiatan ini diselenggarakan di utara ruang kerja Jurusan Teknik Mesin Politeknik Negeri Semarang pada hari yang cerah.Berdasarkan hasil tes dan perhitungan, nilai terkecil dari tahanan pembumian 2 elektroda plat paralel pada kedalaman 60 cm dengan 30 cm soil treatment adalah 13.56 Ω untuk nilai tahanan tanah adalah 6.501 Ω m. Persentase (%) nilai tahanan pembumian sebelum dan sesudah soil treatment pada 2 elektroda plat paralel yang ditanam kedalaman 60 cm dengan 30 cm soil treatment arang adalah 65.646%.]]>
<![CDATA[PENGUJIAN RELAY DIFFERENSIAL GI ]]>
<![CDATA[Hery Setijasa]]>
<![CDATA[ Eksergi Vol 9, No 2 (2013): Mei 2013 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v9i2.192
<![CDATA[Salah satu peralatan proteksi yang digunakan di Gardu Induk adalah Relai Differensial yang digunakan untuk memproteksi Transformator. Relai differensial adalah relai yang bekerja berdasarkan Hukum Kirchof, dimana arus yang masuk pada suatu titik sama dengan arus yang keluar dari titik tersebut. Yang dimaksud titik pada proteksi differensial adalah daerah pengamanan, dalam hal ini dibatasi oleh dua buah trafo arus. Relai ini sangat selektif sehingga biasanya tidak perlu dikoordinasikan dengan relai proteksi lainnya, dan bekerjanya sangat cepat,tidak memerlukan waktu. Proteksi diferensial merupakan salah satu pelindung utama pada transformator daya. Oleh karena itu untuk menjaga keandalannya,dilakukan pemeliharaan dan pengujian pada relai Differensial. Pengujian ini dilakukan untuk Mengetahui apakah relai masih dalam kondisi standar. Kata Kunci : Gardu Induk, Sistem Proteksi Transformator, Relai differensial]]>
<![CDATA[Design of DC Accumulator Charging using Backup Accumulator Based on Inverter and Converter Device ]]>
<![CDATA[Marpaung, Parlindungan Pandapotan]]>
<![CDATA[ Eksergi Vol. 18 No. 2 (2022): MAY 2022 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v18i2.3605
<![CDATA[The charging of DC accumulator thatexperiences a lack of electric charge energy, usuallyutilizes an AC input power from the PLN network. Whenthe AC input power from the PLN network is unavailable,a DC power source is used from the backup DCaccumulator as a substitute. The research objective is todesign an internal DC accumulator charging using abackup DC accumulator equipment based on inverterand converter equipment. The charging system will useinput power from the backup DC accumulator to replacethe AC input power from the PLN network. The electricvoltage of the internal DC accumulator that is filled(charged) is the initial condition of VDC(Acu.Int.)= 8.76 Voltsuntil it reaches the normal condition of 12.05 Volts with acapacity of charging current of 5 Ah (Ampere.hours)absorbs electrical energy of W(Acu.Int.) = 16.45 Wh(Watt.hours). The results show that the equipment supplya DC charger of 13.0 volts and PDCof 21.32 watts to theinternal DC accumulator. The comparison of W(Acu.Int.) to PDC produces time charging, t(charging)of 46.29 minutes]]>
<![CDATA[Solar Cell Performance Test against Load Variations ]]>
<![CDATA[Sumarno, F Gatot]]>;
<![CDATA[Wahyono, Wahyono]]>;
<![CDATA[Mei Hermawan, Baktiyar]]>;
<![CDATA[Hamim Su”™udy, Ahmad]]>;
<![CDATA[Fatowil Aulia, Nur]]>;
<![CDATA[Khoiroh, Ikhwatinah]]>;
<![CDATA[Surindra, Mochammad Denny]]>
<![CDATA[ Eksergi Vol. 18 No. 2 (2022): MAY 2022 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v18i2.3570
<![CDATA[Solar cell is a converter of light energy into electrical energy. This study aims to examine the characteristics of the solar cell to load variations. The research was conducted at the Semarang State Polytechnic Energy Conversion Lab. The solar cell used in the research of the monocrystalline solar cell type KTENG CP-520S. The research method is carried out by measuring the value of solar intensity, voltage and electric current from the solar cell, then calculating the value of the power and efficiency of the solar cell. The greater the intensity of sunlight, the better the characteristics of the solar cell with a note that the solar cell surface temperature must be stable at 250C. The results showed that the highest input power of the solar cell was 5293.69 watts at a lamp load of 115 watts at 833.6 W/m2 of radiation during sunny weather. The highest value of the output power of the solar cell is 191.52 watts when the lamp is loaded with 190 watts of radiation at 739.4 W/m2 during sunny weather. While the highest value of the load output power is 212.43 watts when the lamp is loaded with 200 watts of radiation at 724.4 W/m2 when the weather is sunny. The highest efficiency of the solar cell is 4.13% when the lamp is loaded with 200 watts of radiation at 724.4 W/m2 when the weather is sunny. And the highest value of Solar Power Plant efficiency is 4.61% at a 200 watt lamp loading at 724.4 W/m2 radiation when the weather is sunny.]]>
<![CDATA[Comparison of Injection Characteristics and Droplet Distribution on Crude Palm Oil and Diesel Using CFD ]]>
<![CDATA[Suprianto, Teguh]]>;
<![CDATA[Darmansyah, Darmansyah]]>;
<![CDATA[Hasbi, Muhammad]]>
<![CDATA[ Eksergi Vol. 18 No. 2 (2022): MAY 2022 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v18i2.3225
<![CDATA[CPO (Crude Palm Oil) is a potential renewablefuel as a substitute for fossil fuels used in internal combustionengines. An important parameter that affects the combustion ofan engine with an injection system is the characteristics of thefuel spray. This research was conducted using ComputationalFluid Dynamics (CFD) software to model the atomizationprocess that occurs when CPO and diesel fuel are injected witha pressurized atomizer. The modeling shows the characteristicsof the spray which include the shape of the spray and the dropletdiameter distribution. These characteristics are presented withspray images, droplet diameter distribution graphs, and velocitydistribution graphs. Simulations show that at temperaturesabove 75 °C and 100 °C, CPO spray produces droplet shapes anddistributions that are almost the same as diesel spray. On theother hand, diesel injection spray produces a lower droplet size.The highest droplet size distribution is at 12-16 microns.]]>
<![CDATA[Performance of Magneto Hydro Dynamic (MHD) as a Power Generation Support Tool ]]>
<![CDATA[Purwati W, Wiwik]]>;
<![CDATA[Atmojo, Slamet Priyo]]>;
<![CDATA[Margana, Margana]]>;
<![CDATA[Suwarti, Suwarti]]>;
<![CDATA[Prasetiyo, Budhi]]>;
<![CDATA[Khoiroh, Ikhwatinah]]>
<![CDATA[ Eksergi Vol. 18 No. 2 (2022): MAY 2022 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v18i2.3571
<![CDATA[Magnetohydrodynamics is a method for generating electricity by utilizing the interaction between a magnetic field and an electrolyte fluid. MHD components: salt water electrolyte, Neodymium N52 magnet, and Cu-Zn electrode. The MHD used is a coarse salt water electrolyte. The purpose of the MHD model is as an innovative technological breakthrough that is used to support increasing the efficiency of the power generation system. The lowest efficiency is shown in the second data with variations in salt content of the 5 grams/liter experiment without MHD support, which is 0.08%. The highest efficiency is shown in the twentieth data with variations in salt content of the 95 gram/liter experiment supported by MHD, which is 0.59%. The maximum efficiency increase that can be achieved is 0.37% with variations in salt content of 60 grams/liter.]]>
<![CDATA[Testing the Effect of Variation of Deflector Shapes on the Performance of the Three Blade Vertical Axis Savonius Water Turbine ]]>
<![CDATA[Gunawan, Gad]]>;
<![CDATA[Susilo, Rizky Dwi]]>;
<![CDATA[Kurniawati, Diniar Mungil]]>
<![CDATA[ Eksergi Vol. 18 No. 2 (2022): MAY 2022 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v18i2.3273
<![CDATA[Hydropower is energy obtained from flowingwater and can be used for mechanical energy or electricalenergy. Electrical energy is energy that is used to fulfill humanneeds in life. The need for electrical energy in Indonesiacontinues to increase by an average of 3.9% from year to yearuntil 2050. There are various water sources in Kalimantansuch as water ditches, as well as reservoirs that have low-speedwater flow and the capacity to accommodate water levels thatare not too high. The Savonius water turbine can be utilized inthese conditions because it has the advantage of a simpleturbine construction, and is suitable for relatively low velocitywater flows. This study analyzes how well the Savonius waterturbine is by applying different deflector shapes. The methodapplied in this experiment is an experimental study using aSavonius turbine. The conclusion in this study is that applyinga deflector will improve turbine performance much better thannot using a deflector. Experiments by applying deflectors,namely convex deflectors, flat deflectors, and concavedeflectors, it was concluded that the application using aconcave deflector resulted in the highest rotational speedproduced by the turbine, the maximum value of turbine powerand the Savonius turbine coefficient of 206.3 rpm, 0.196 Wattand Cp = 0.124.]]>
<![CDATA[Reverse Time During Current Relay Performance to Support the Protection System Practicum ]]>
<![CDATA[Wahyono, Wahyono]]>;
<![CDATA[sumarno, F. Gatot]]>;
<![CDATA[W, wiwik Purwati]]>;
<![CDATA[margana, margana]]>;
<![CDATA[suwarti, Suwarti]]>;
<![CDATA[N., Ajie Pribadi]]>
<![CDATA[ Eksergi Vol. 18 No. 2 (2022): MAY 2022 ]]>
Publisher : <![CDATA[Politeknik Negeri Semarang ]]>
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DOI: 10.32497/eksergi.v18i2.3572
<![CDATA[””Overcurrent Relay is one of the protection system tools in the electricity network. Overcurrent Relay works based on the increase in fault current that exceeds a certain safety value and a certain period of time. The type of relay that will be used in this test is the IDMT NX203A Overcurrent Relay. The purpose of this test is to get a good practicum module and to prove the inverted time relay characteristic curve according to British Standard BS142. In the test, the tool to be assembled is tested for its work function so that in data collection errors can be avoided while the relay on the module will be given a current setting of 2A; 3A; and 4A with TMS0.05; 0.5; and 1.0 which will be connected to a digital timer so that if the fault current exceeds the setting current, the relay will automatically give a signal and the digital timer will show the time when the current is cut off. The final result is a practicum module where each tool functions under normal working conditions and a graph of time against relay current for setting current 2A, fastest time 0.498s at 9A fault current and 0.05 TMS, longest time 12.991s at 4A TM fault current. . 1.0. Current setting of 3A for the fastest time is 0.572s at fault current of 9A and TM 0.05, for the longest time is 35.854s at fault current of 4A and TM 1.0. Current setting of 4A for the fastest time is 0.708s at fault current of 9A and TM 0.05, for the longest time is 55.979s at fault current of 5A and TM 1.0.]]>
