Sjamsjul Anam

Optimal controller for doubly fed induction generator (DFIG) using Differential Evolutionary Algorithm (DE)

Variable-speed wind turbine (VST) with doubly-fed induction generator (DFIG) is one type of wind power that capable of producing electrical energy efficiently, capable of controlling real and reactive power generator, and improves the power quality. However, DFIG wind turbine has a variable-frequency AC / DC / AC converter (VFC) and IGBT switches that very sensitive to overcurrent which occur during transient disturbance. To protect the DFIG rotor circuit from excessive current, the rotor side converter will be blocked when VFC trip, so the DFIG detached from power system. Release of DFIG during disturbances can cause the production of electricity will be disrupted. By applying the proper control design, the quality of electricity supply during a disturbance can be corrected. In this research, the optimal design of PI controller in the rotor side converter (RSC) with DFIG wind turbine using the Differential Evolutionary Algorithm (DE) is proposed to improve the DFIG performance during disturbance. The simulation results indicate that the application of optimal design of PI controller on DFIG using DE can improve the performance of DFIG during disturbances. It shown by the significantly reducing of overshoot rotor current and voltage DC-link of DFIG with the optimized design when compared with the initial controller design system.

Dynamic optimal power flow with geothermal power plant under take or pay energy contract

This paper deals with dynamic optimal power flow (DOPF) considering geothermal power plant under take or pay (TOP) contract. As located in ring of fire, Indonesia has high potential of geothermal resources. Therefore, geothermal power plant becomes promising solution of power shortage in Indonesia. However, it takes high investment cost to develop geothermal power plant. In order to attract the investors to spend their money in developing geothermal power plant, the Indonesian government applies take or pay scheme in buying electric power from geothermal unit. This scheme is aimed to ensure cost recovery of the unit. When applying take or pay scheme, system operator may use DOPF formulation to make daily operation planning. The DOPF problem is solved using Matlab-based quadratic programming (QP). Then, IEEE 30 bus system is employed as tested system to show the effectiveness of the proposed approach.

Comparisons of Cuk, SEPIC and Zeta converter performance for harmonics mitigation and PFC in BLDC speed control

Brushless dc motor (BLDC) is type of dc motor that efficiently use for electric appliances compared with another types of electric motor. BLDC is used in many applications, such as household applications, transportations, aerospace, heating, ventilating, robotics, and many others. BLDC is typically configurated with ac source, DBR (Diode Bridge Rectifier) and connecting capacitor. Because of BLDC needs square waveform current to work therefore, it is necessary to use inverter to convert the dc current to modified ac current. In this case, inverter also required to control the speed of BLDC. Usually, conventional speed control methods which only use DBR and inverter resulting high amount of harmonics and reducing the power factor at the ac input. To overcome this problem in this paper describes several methods that are already designed and examined speed control for BLDC to realize the idea of this research three types of converters, Cuk, SEPIC, and Zeta are utilized to be used for harmonics mitigation and power factor correction (PFC) in BLDC speed control application.

MPPT design on solar farm using perturb and observe technique considering tilt angle and partial shading in Giligenting Island

Giligenting Island is located in Sumenep, Madura. It is very potential for application the renewable energy. Based on the measurement, the maximum potential irradiance solar farm in the Island is accounted 610 W/m2. To convert the irradiance power to electricity, photovoltaic is applied. However, photovoltaic modules are drastically decrease their power output in case of the partial shading conditions. Therefore, perturb and obverse method (PnO) is introduced to track the point to establish the maximum power. In addition, the maximum power point tracking (MPPT) is employed to reduce the shading effects, thus by both method, the power generated is maximum. Besides, this technique is able to overcome the limitations in tracking efficiency, oscillation in steady state, and transient period. In this paper to maximize the irradiance observation, optimal site selection is undertaken by considering the tilt angles of PV and by approaching a sun path diagram model. Based on this study and experiment that have been taken in Giligenting Island, it is summed up that the proposed MPPT algorithm is superior to P&O technique with varies partial shading conditions. The results of the simulation yield that the power output of photovoltaic cover 99.4% of the load demand in Giligenting Island.

Analisa Arc Flash pada Sistem Kelistrikan Di PT. Asahimas Flat Glass Tbk. Sidoarjo

Arc Flash adalah total energi yang dilepaskan ketika terjadi gangguan hubung singkat. Energi akan dilepaskan melalui udara mengalir ke fasa lain, netral atau mengalir ke tanah. Ketika pekerja yang tidak dilengkapi alat pelindung diri berada di dekat dengan Arc Flash, maka akan menyebabkan cedera serius dan bahkan kematian. Berdasarkan standar IEEE 1584-2002 yang mengatur tentang analisa bahaya busur api pada sistem tegangan rendah dan menengah, pengguna dapat dengan mudah menentukan batas keamanan untuk para pekerja. Menurut rekomendasi standar IEEE perhitungan arus hubung singkat selalu memperhatikan kontribusi arus gangguan dari generator, motor induksi dan sinkron. Besar kecilnya energi arc flash dapat ditentukan dari beberapa sudut pandang. Diantaranya ialah nilai energi arc flash akan besar apabila dihitung dengan menggunakan arus bolted three phase fault, sedangkan dari sudut arc clearing time yang didapat dari waktu dimana arus gangguan saat itu terjadi akan menghasilkan nilai energi busur api yang lebih rendah. Untuk mengurangi atau menurunkan nilai dari arc clearing time ini banyak metode yang digunakan, diantaranya adalah melakukan resetting koordinasi proteksinya seperti yang dilakukan dalam tugas akhir ini. Untuk hasil yang didapat pada tugas akhir ini adalah pada tipikal 1 nilai insiden energi tertinggi 31.576 cal/cm2 turun menjadi 10.764 cal/cm2 , pada tipikal 2 nilai insiden energi tertinggi 30.387 cal/cm2 turun menjadi 16.8 cal/cm2, pada tipikal 3 nilai insiden energi nya mengalami penurunan yaitu dari 30.513 cal/cm2 menjadi 15.94 cal/cm2.

Evaluasi Koordinasi Proteksi Akibat Penambahan Pembangkit Dan Rekonfigurasi Jaringan di Joint Operation Body Pertamina-Petrochina East Java (JOB P-PEJ), Tuban

Joint Operation Body (JOB) Pertamina-Petrochina East Java adalah sebuah kerjasama dua perusahaan besar berskala internasional yang sedang melakukan eksplorasi di Indonesia Untuk meningkatkan produksi pada Central Processing Area (CPA) ditambahkan dua pembangkit dengan daya 4X600HP, 4.16kV. Dengan penambahan beban dan pembangkit muncul permasalahan pada sistem kelistrikannya, yaitu sering terjadi padam total (blackout) pada saat terjadi gangguan, sehingga kontinuitas daya terganggu. Melalui tugas akhir ini dilaksanakan evaluasi koordinasi proteksi pada Joint Operation Body (JOB) Pertamina-Petrochina East Java yang tepat dalam mendeteksi dan mengisolir gangguan sehingga tidak mengganggu sistem yang berjalan dan mencegah kerusakan peralatan listrik. Dari hasil plot koordinasi kurva arus waktu kondisi existing dapat diketahui bahwa terdapat misscoordination dan overlaping. Melalui hasil analisis dan perhitungan manual direkomendasikan penyetelan pick up rele arus lebih dan penyetelan grading time rele. Rele yang perlu disetel ulang adalah rele arus lebih gangguan fasa (overcurrent relay) dan rele arus lebih gangguan tanah (ground fault relay). Setting rele dengan penambahan pengaman pada rele 88. Dengan memakai konfigurasi stand alone harus ditambahkan trafo sebesar 4 MVA pada sisi outgoing generator centaur 2 sehingga dapat digunakan data Load Flow & Short Circuit