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Optimal Design of Hydrogen Based/Wind/Microhydro Using Genetic Algorithm Soedibyo, Soedibyo; Suryoatmojo, Heri; Robandi, Imam; Ashari, Mochamad
TELKOMNIKA Telecommunication, Computing, Electronics and Control Vol 10, No 4: December 2012
Publisher : Universitas Ahmad Dahlan

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Abstract

The target of stand-alone hybrid power generation system was to supply the load demand with high reliability and economically as possible. To design these criteria the optimal design of the proposed configuration should be done by using intelligent optimization technique. This study utilized Genetic Algorithm method to determine the optimal capacities of hydrogen, wind turbines and micro hydro unit according to the minimum cost objective functions that relate to these two factors. In this study, the cost objective function included the annual capital cost, annual operation maintenance cost, annual replacement cost and annual customer damage cost. The proposed method had been tested in the hybrid power generation system located in Leuwijawa village in Central Java of Indonesia. Simulation results showed that the optimum configuration can be achieved using 19.85 ton of hydrogen tanks, 21 x 100 kW wind turbines and 610 kW of micro hydro unit respectively.
Advanced DVR with Zero-Sequence Voltage Component and Voltage Harmonic Elimination for Three-Phase Three-Wire Distribution Systems P, Margo; Purnomo, Mauridhi Heri; Ashari, Mochamad; P, Zaenal; Hiyama, Takashi
IPTEK The Journal for Technology and Science Vol 20, No 4 (2009)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (878.35 KB) | DOI: 10.12962/j20882033.v20i4.21

Abstract

Dynamic Voltage Restorer (DVR) is a power electronics device to protect sensitive load when voltage sag occurs. Commonly, sensitive loads are electronic-based devices which generate harmonics. The magnitude and phase of compensated voltage in DVR depend on grounding system and type of fault. If the system is floating, the zero sequence components do not appear on the load side. Meanwhile, in a neutral grounded system, voltage sag is extremely affected by zero sequence components. A blocking transformer is commonly installed in series with DVR to reduce the effect of zero sequence components. This paper proposes a new DVR control scheme that is capable of eliminating the blocking transformer and reducing harmonic distortion. The system uses fuzzy polar controller to replace the conventional PI or FL controller that is commonly used. By taking into account the zero sequence components in the controller design, the effects of zero sequence components can be compensated. Simulated results show the effectiveness of the proposed DVR controller
Desain dan Simulasi Switched Filter Compensation Berbasis Tri Loop Error Driven Weighted Modified PID Controller untuk Peningkatan Kualitas Daya Listrik Putra, Mochamad Wahyu Jasa; Ashari, Mochamad; Putri, Vita Lystianingrum Budiharto
Jurnal Teknik ITS Vol 1, No 1 (2012): Jurnal Teknik ITS (ISSN 2301-9271)
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat (LPPM), ITS

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Abstract

SFC (Switched Filter Compensation) merupakan bagian dari FACTS devices yang digunakan untuk meningkatkan kualitas daya listrik pada sistem transmisi yang dipasang pada sisi pengirim daya. SFC terdiri dari sebuah kompensasi seri dan dua kompensasi shunt. Pada tugas akhir ini dilakukan desain SFC yang dikontrol dengan menggunakan tri loop error driven yang tergabung dengan weighted modified PID. Hasil simulasi menunjukkan bahwa pemasangan SFC berbasis dua kompensasi seri dan dua kompensasi shunt dapat menaikkan tegangan bus generator, perbaikan power factor dan mengurangi THD. Pengujian pada sistem menunjukkan bahwa SFC memiliki respon yang baik ketika terjadi gangguan pada sistem.
Simulasi Dinamika untuk Menentukan Stabilitas Sistem Tenaga Listrik Menggunakan Thyristor Controlled Braking Resistor pada Sistem IEEE 34 Node Test Feeder Taufiq, Andi; Penangsang, Ontoseno; Ashari, Mochamad
Jurnal Teknik ITS Vol 1, No 1 (2012): Jurnal Teknik ITS (ISSN 2301-9271)
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat (LPPM), ITS

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Abstract

Terdapat berbagai macam metode untuk meningkatkan stabilitas sistem  tenaga listrik. Salah satunya adalah dengan menggunakan metode pengereman dinamis (dynamic braking). Generator sinkron sebagai distributed generator yang digerakkan oleh mesin diesel. Pada saat terjadi gangguan pada sistem, digunakan sebuah Thyristor Controlled Braking Resistor (TCBR) untuk meredam osilasi yang terjadi. Sistem yang hendak dianalisis dinamika dan stabilitasnnya adalah IEEE 34 node test feeder. Dengan sistem ini diilustrasikan karakteristik dan keefektifan TCBR untuk meredam osilasi frekuensi rendah dan mencegah terjadinya ketidakstabilan transien sistem. Dari hasil analisis diperoleh bahwa dengan adanya penambahan TCBR (Thyristor Controlled Braking Resistor) maka respon transien sistem akan menjadi lebih baik. Hal ini ditunjukkan dengan adanya penurunan overshoot dan settling timenya. Dengan demikian sistem akan menuju kondisi stabil dengan lebih cepat setelah terjadi gangguan.
Performance Fuzzy Logic Control to Minimize Output Voltage Ripple and Balanced Current Distribution of DC-DC Converters in Parallel Non-Identical Suprianto, Bambang; Ashari, Mochamad; Purnomo, Mauridhi Hery
IPTEK The Journal for Technology and Science Vol 21, No 1 (2010)
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (942.79 KB) | DOI: 10.12962/j20882033.v21i1.28

Abstract

Analysis of DC-DC converters are arranged in parallel with the inductor parameters which are different from what discussed in this paper. Buck DC-DC converter using non-identical model, that is different in the value of inductance which is L1 ≠ L2 ≠ L3. Research techniques are taken from the difference of current flows of each converter i.e. I1-I2 and I1- I3 and the reference current is I1. This current difference results are used as input controller. PID and Fuzzy Inference System with 5 gbell membership function are used as a controller. The results of this study indicate a significant system performance. Output voltage ripple is 10 mV with the total output current is 63.7 Ampere. Each DC-DC converter provides a current of contribution to the load 21.28 Ampere. The difference of the current distribution of each converter module range is 1mA - 4mA RMS (Root Mean Square) using PID control, while using Fuzzy Logic Control for differences in the distribution of current is 0.1 mA RMS and the output voltage is 48 volt. Fuzzy Logic Control performance has shown an improvement of control systems to reduce the output voltage ripple and the ability to share load current equally into each DC-DC converter.
Maximum Output Power Tracking of Wind Turbine Using Intelligent Control Yuhendri, Muldi; Ashari, Mochamad; Hery Purnomo, Mauridhi
TELKOMNIKA Telecommunication, Computing, Electronics and Control Vol 9, No 2: August 2011
Publisher : Universitas Ahmad Dahlan

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Abstract

The output power of wind turbine is determined by wind speed. The Output power can be adjusted by controlling the generator speed and pitch angle of wind turbine. When the wind speed below the wind turbine rated, the output power of generator can be maximized by controlling the generator speed at point of maximum power coefficient. When the wind speed above the wind turbine rated, output power of wind turbine will exceed the power generators rated. In this condition, the output power of wind turbine needs to be regulated to conform to the generator power rate. Output power of wind turbine can be regulated by adjusting the pitch angle of wind turbine. In this paper is developed the control strategies based intelligent control for controlling the generator speed and pitch angle of wind turbine, so the maximum output power tracking (MOPT) of wind turbine can be obtained at any wind speed variations. Generator speed is controlled using PI Fuzzy Logic Controller (PI-FLC) based Direct Field Oriented Control (DFOC). Pitch angle of wind turbine is controlled using Elman Recurrent Neural Network (RENN). The simulation results with Matlab Simulink shows that the both controller was successfully regulates the output power when the wind speed above the wind turbine rated and the output power can be maximum when the wind speed below the wind turbine rated.
Desain dan Simulasi Konverter Boost Multilevel Sebagai Catu Daya Kendaraan Listrik Fanani, Akhmad Zaky; Ashari, Mochamad; Yuwono, Teguh
Jurnal Teknik ITS Vol 3, No 1 (2014)
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat (LPPM), ITS

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Abstract

Konverter boost multilevel merupakan jenis dc-dc konverter yang dapat  menaikkan tegangan output. Prinsip kerja konverter ini sama dengan konverter boost konvensional akan tetapi memiliki keuntungan yaitu besar ratio tegangan output yang lebih tinggi. Keuntungan ini dapat diterapkan pada motor listrik sebagai pengendali catu daya.  Konverter boost multilevel berfungsi untuk menaikkan tegangan dari baterai ke motor.Pada tugas akhir ini dibahas desain dan simulasi konverter boost  dengan dua induktor yang dilengkapi dengan transformator tambahan dan konverter boost multilevel menggunakan kapasitor yang di 3 tingkat. Simulasi yang dilakukan pada tugas akhir ini adalah penerapan konverter boost  dengan dua induktor yang dilengkapi dengan transformator tambahan dan konverter boost multilevel yang diberi beban berupa motor dc. Dari hasil simulasi diamati karakteristik tegangan output pada konverter-konverter boost tersebut sehingga dapat ditentukan jenis konverter boost yang tepat untuk catu daya kendaraan listrik
Perancangan dan Simulasi Full Bridge Inverter Lima Tingkat dengan Dual Buck Converter Terhubung Jaringan Satu Fasa Fuadi, Zamratul; Ashari, Mochamad; Pamuji, Feby Agung
Jurnal Teknik ITS Vol 3, No 1 (2014)
Publisher : Lembaga Penelitian dan Pengabdian Kepada Masyarakat (LPPM), ITS

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Abstract

Inverter merupakan perangkat elektronika daya yang berfungsi mengonversi sumber searah menjadi bolak-balik. Full bridge inverter adalah satu jenisnya yang mampu menghasilkan tegangan tiga tingkat jika menggunakan teknik modulasi unipolar. Penambahan sirkuit dual buck converter pada full bridge inverter mampu menghasilkan tegangan dalam lima tingkat. Dua saklar pada rangkaian dual buck converter switching pada frekuensi tinggi 20 kHz, sedangkan empat saklar pada full bridge inverter switching pada frekuensi rendah 50 Hz. Teknik modulasi in phase disposition PWM (PDPWM) digunakan untuk mengatur penyalaan saklar dual buck converter. Keluaran inverter lima tingkat dibandingkan dengan tiga tingkat. Total harmonic distortion tegangan (THDV) dan arus (THDi) inverter lima tingkat bernilai 23.2281 % dan 23.0975 %, sedangkan inverter tiga tingkat sebesar 51.9302 % dan52.2458 %. Ketika daya 1004.08 watt disumbangkan ke jala-jala, inverter lima tingkat menghasilkan power factor senilai 0.99 dan THDi 4.1 %. Pada sumbangan daya yang sama, inverter tiga tingkat menghasilkan power factor sebesar 0.919 dan THDi bernilai 45.64 %.
Distribution Network Efficiency Improvement Based on Fuzzy Multi-objective Method Syahputra, Ramadoni; Robandi, Imam; Ashari, Mochamad
IPTEK Journal of Proceedings Series Vol 1 (2014): International Seminar on Applied Technology, Science, and Arts (APTECS) 2013
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v1i1.422

Abstract

This paper presents a reconfiguration methodology based on a fuzzy multi-objective approach for achieving the minimum active power loss and the maximum voltage magnitude of radial distribution networks with distributed generations in order to improve the distribution system efficiency. Multi-objective function are considered for load balancing among the feeders, minimization of the real power loss, and deviation of bus voltage, while subject to a radial network structure in which all loads must be energized. These objective functions are modeled with fuzzy sets to evaluate the imprecise nature of each objective. Originality of the research is that the fuzzy-based multi-objective optimization in reconfiguration of distribution network including the distributed generation. The implementation of the fuzzy multi-objective for distribution reconfiguration on a 77 bus distribution network with distributed generation is described. The simulation results show that a 1.80% of electric power distribution network efficiency improvement is achieved by the method
Design and Implementation of Photovoltaic Single Stage Inverter Connected to Grid Prasetyo, Bayu; Ashari, Mochamad; Riawan, Dedet Candra
IPTEK Journal of Proceedings Series Vol 1 (2014): International Seminar on Applied Technology, Science, and Arts (APTECS) 2013
Publisher : Institut Teknologi Sepuluh Nopember

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.12962/j20882033.v1i1.413

Abstract

Photovoltaic system that connected to grid is a system which applied for an area that can be reach by transmission line. This system as a support for conventional generating system. If there is a power from PV system, then power demand supplied from photovoltaic generating system. Otherwise, power demand supplied from conventional generating system. As a support conventional generating system, there is many methods to convert photo energy into AC system that connected to grid. One of conventional methods as a two stage inverter, this methods need two process to convert photovoltaic into AC system. First stage, conversion photovoltaic power to DC system. In this stage PV processed by buck boost converter. Second stage, that DC power from first stage changed into AC power system. This two stage process has low efficiency, so we try to make the process simply and more efficiency. New method called single stage inverter can be applied. With this methods, conversion DC power system from PV can be done by single stage process. From this single process, we expext that more efficiency can be achieved.