Arif Musthofa

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.

Economic Load Dispatch Unit Pembangkit Termal Mempertimbangkan Penambahan Pembangkit Tenaga Angin Dengan Menggunakan Firefly Algorithm

Maraknya isu global warming serta keterbatasan sumber daya alam membuat mulai banyaknya dibangun pembangkit-pembangkit listrik dengan renewable energy, salah satunya adalah pembangkit tenaga angin. Pada jurnal ini, firefly algorithm diterapkan untuk mengoptimasi total biaya pembangkitan 2 buah sistem uji, tanpa dan dengan mempertimbangkan penambahan tenaga angin. Hasil simulasi menunjukkan bahwa dengan penambahan pembangkit tenaga angin ke dalam sistem tenaga listrik, total biaya pembangkitan tidak selalu lebih murah. Selain itu, hasil simulasi juga menunjukkan bahwa firefly algorithm sebagai metode optimasi dapat menyelesaikan permasalahan economic load dispatch (ELD) lebih baik dibandingkan metode lain yang sudah dilakukan, yaitu particle swarm optimization (PSO), bat algorithm (BA), biogeography-based optimization (BBO) dan plant growth simulation algorithm (PGSA) dengan persentase selisih nilai penghematan total biaya berkisar antara 0.32% (

Vibration analysis for the classification of damage motor PT Petrokimia Gresik using fast fourier transform and neural network

50) hingga 9.27% (

A study on reducing inrush current in Kenjeran 150 KV substation power transformer by installing VCT-ICL

11884).

Design on-line monitoring and sensitive fault detection for three phase induction motor

The electric motor is an important equipment to use in the industrialized world. Because its function is very crucial, so the damage of this electric motor will directly affect the production performance. In this research, the vibration data of electric motor at PT. Petrokimia Gresik has been classified based on physical damage which is using both of Fast Fourier Transform (FFT) and neural network methods. There are 5 types of conditions to classify the damage of electric motors using a neural network, namely normal condition, unbalance, miss-alignment, looseness, and antifriction. From the results obtained, the differences amplitude values from each condition. This level of accuracy of neural network method for detecting the damage motors in this study is 100% accurate.

Investigation of intrinsic breakdown of transformer oil insulation: An experimental approach

Reduction of inrush current at power transformers can be done by using the VCT-ICL which is a modification of the DC-type reactor inrush current limiter with the addition of VCT components which contribute to reducing distortion in the voltage waveform. Through ATP-EMTP program, the simulation is performed by obtaining three modeling conditions, namely the existing modeling system (before being installed VCT-ICL), modeling once ICL (DC reactor) installed, and modeling once VCT-ICL installed. From the modeling results, the comparison inrush currents and voltages of the three conditions of modeling can be evaluated. The value of the impedance at VCT-ICL proportional to the value of inrush current is reduced, so the method is flexible enough to reduce inrush currents such as ICL (DC reactor). However, the simulation results prove that the distortion in the voltage waveform occur in conditions after the ICL (DC reactor) has been installed. Then after VCT mounted on ICL with DC reactor parameter values are the same, the distortion generated due to the installation of DC reactor can be reduced.

Koordinasi Proteksi Saluran Udara Tegangan Tinggi pada Gardu Induk Mliwang – Tuban Akibat Penambahan Penghantar Pltu Tanjung Awar-Awar

On-line monitoring system is one of the solutions to avoid catastrophic failure in machine, including induction motor. The most common fault in induction motor is stator winding failures that initiated by inter-turn short circuit. In this paper, induction motor monitoring and fault detection system is proposed based on microcontroller which is displayed on computer monitor. Several measurement variables are displayed in on-line monitoring interface such as voltage, current, speed, and stator temperature. Moreover, the diagnostic system is developed to detect inter-turn short circuit. Based on the testing result, the proposed system is successfully to detect one-turn short circuit fault or less than one percent of stator winding.

Analisis Medan Magnetik terhadap Operator yang Bekerja di Saluran Transmisi Menggunakan 3D Metode Elemen Hingga

In this study Investigation of intrinsic breakdown of transformer oil insulation has been done. Three samples of transformer oil insulation were tested under impulse voltage stress as well as under ac voltage. These three samples were used, non-treatment, and treatment transformer oil from a same company. The results show that under impulse voltage of 1.2/50 μs oil under tested remarkable difference between used oil and new oil of about 45kV and 87 kV, respectively. This difference results may show that the rise time of applied voltage was not representatively fast to investigate the intrinsic dielectric strength of sample under tested. However, new treated oil as well as non-treated has the same order of breakdown voltage under impulse voltage stress. Moreover under power frequency applied voltage, three sample under tested have notable difference breakdown voltage which the treated oil insulation has the highest breakdown voltage of about 50 kV. These are reasonable result and can be explained by using all of at this juncture developed breakdown mechanism theories.