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29,325 Article Results

Netload-constrained Unit Commitment Considering Increasing Renewable Energy Penetration Levels: Impact of Generation Schedules and Operational Cost

10.11591/ijape.v7.i1.pp87-98
Saleh Y. Abujarad , M. W. Mustafa , J. J. Jamian , Abdirahman M. Abdilahi , N. Zareen
In the context of low carbon power systems, the penetration levels of Renewable Energy Sources (RES) are expected to increase dramatically. In this regard, this paper investigates the maximum RES penetration level constrained by net load while considering an inflexible Unit Commitment (UC) model. To solve the UC problem, an enhanced priority list (EPL) based method is developed. In the proposed method, the plants were activated sequentially based on the operational price. The system constraint violations were repeatedly corrected until all system constraints (such as net load and spinning reserves) were satisfied. The proposed EPL method was efficient to achieve a near optimal solution under high shares of RES. Furthermore, the research work investigates three different scenarios representing penetration levels of 10% solar-only, 14.5% wind-only and 27.5% mixture of both solar and wind. The impact of each penetration level on the system scheduling and operational cost were analyzed in detail. The analysis presented shows that a potential operational cost savings of 21.6 $/MW, 20 $/MW and 11.1 $/MW is feasible under each of the represented scenarios, respectively.
Volume: 7
Issue: 1
Page: 87-98
Publish at: 2018-04-01

Ecological and Economical Friendly Analysis of A Hybrid Solar-Grid-Diesel Connected Power Generation System

10.11591/ijape.v7.i1.pp1-9
Rafat Qonain , Malik Rafi , Imran Khan , Shivley Sageer
This paper presents Importance of hybrid power system. This paper depicts model and simulation of a renewable energy based hybrid power system for improving power quality because optimal utilization of primary energy sources will increase the level of supply reliability. The combination of Grid, Photo Voltaic (PV) Array System, and Diesel generator systems are used for power generation. Due to variation in output power of solar panel, Diesel engine is also coupled to ensure reliable supply under all conditions. The results shows that the proposed hybrid power system can effectively manage the optimal utilization of primary energy sources and improves the power quality in an islanding as well as grid connected mode.
Volume: 7
Issue: 1
Page: 1-9
Publish at: 2018-04-01

Vector Control of VSC HVDC System under Single Line to Ground Fault Condition

10.11591/ijape.v7.i1.pp59-64
Prabodha Kumar Rath , Kanhu Charan Bhuyan
This paper proposes a model of a VSC (voltage source converter) based Back to Back HVDC system and its control technique under fault condition. From the mathematical model of the system relationship between the controlling and the controlled variables is determined to control the system parameters. An appropriate vector control technique is used to control active and reactive power and to maintain DC link voltage. The proposed controlling unit consists of outer control loop and inner control loop which effectively damped out the system oscillation and maintains the system stability. The validity of the model and the feasibility of the control method have been proved by the simulation results. In this paper the system performance is studied under fault condition is studied.
Volume: 7
Issue: 1
Page: 59-64
Publish at: 2018-04-01

Three Area Power System Load Frequency Control Using Fuzzy Logic Controller

10.11591/ijape.v7.i1.pp18-26
C. R. Balamurugan
System frequency is one of the most important parameters of a power system. Du to generation-load mismatches, the system frequency can vary over a small range. When the power consumed by loads and overall losses is greater than the generated power, the operating frequency of the system will decrease, resulting in a situation known as the under frequency condition. In some other case, if some of the loads in a system are disconnected from the system suddenly, or lost, it leads to a condition called as the over frequency condition. This condition is char acterized by greater input power than the consumed power by the loads. The rest of the loads in the system will absorb the extra power and the generator inertia, leading to an increase in the system frequency. In both the cases, the system frequency fluctuates from the power system’s limited frequency range, further leading to tripping off of the substation and further collapsing of the entire system. The paper describes a new method employing a smart meter to monitor and control the power system frequency which changes according to the loading conditions in the system, whether under load condition or overload condition. 
Volume: 7
Issue: 1
Page: 18-26
Publish at: 2018-04-01

The Effects of Segmentation Techniques in Digital Image Based Identification of Ethiopian Coffee Variety

10.12928/telkomnika.v16i2.8419
Abrham Debasu; Bahir Dar University Mengistu
This paper presents the effects of segmentation techniques in the identification of Ethiopian coffee variety. In Ethiopia, coffee varieties are classified based on their growing region. The most widely coffee growing regions in Ethiopia are Bale, Harar, Jimma, Limu, Sidamo and Welega. Coffee beans of these regions very in color shape and texture. We investigated various segmentation techniques for efficient coffee beans variety identification system. Images of six different coffee beans varieties in Oromia and Southern Ethiopia were acquired and analyzed. For this study Otsu, Fuzzy-C-Means (FCM) and Kmeans segmentation techniques are considered. For classification of the varieties of Ethiopian coffee beans back propagation neural network (BPNN) is used. From the experiment 94.54% accuracy is achieved when BPNN is used on FCM segmentation technique.
Volume: 16
Issue: 2
Page: 713-717
Publish at: 2018-04-01

Research on 4-dimensional Systems without Equilibria with Application

10.12928/telkomnika.v16i2.8507
Ruibin; University of Science and Technology Beijing Hao , Lequan; University of Science and Technology Beijing Min , Hongyan; University of Science and Technology Beijing Zang
Recently chaos-based encryption has been obtained more and more attention. Chaotic systems without equilibria may be suitable to be used to design pseudorandom number generators (PRNGs) because there does not exist corresponding chaos criterion theorem on such systems. This paper proposes two propositions on 4-dimensional systems without equilibria. Using one of the propositions introduces a chaotic system without equilibria. Using this system and the generalized chaos synchronization (GCS) theorem constructs an 8-dimensional discrete generalized chaos synchronization (8DBDGCS) system. Using the 8DBDGCS system designs a 216-word chaotic PRNG. Simulation results show that there are no significant correlations between the key stream and the perturbed key streams generated via the 216-word chaotic PRNG. The key space of the chaotic PRNG is larger than 21275. As an application, the chaotic PRNG is used with an avalanche-encryption scheme to encrypt an RGB image. The results demonstrate that the chaotic PRNG is able to generate the avalanche effects which are similar to those generated via ideal chaotic PRNGs.
Volume: 16
Issue: 2
Page: 811-826
Publish at: 2018-04-01

Street Mark Detection Using Raspberry PI for Self-Driving System

10.12928/telkomnika.v16i2.4509
Sumardi; Diponegoro University Sumardi , Muhammad; Diponegoro University Taufiqurrahman , Munawar A; Diponegoro University Riyadi
Self driving is an autonomous vehicle that can follow the road with less human intervention. The development of self driving utilizes various methods such as radar, lidar, GPS, camera, or combination of them. In this research, street mark detection system was designed using webcam and raspberry-pi mini computer for processing the image. The image was processed by HSV color filtering method. The processing rate of this algorithm was 137.98 ms correspondinig to 7.2 FPS. The self-driving prototype was found to be working optimally for “hue” threshold of 0-179, “saturation” threshold of 0-30, and “value” threshold of 200-255. Street mark detection has been obtained from the coordinates of street mark object which had range 4-167 on x axis and 4-139 on y axis. As a result, we have successfully built the street mark detection by COG method more effectively and smoothly in detection in comparison with Hough transform method.
Volume: 16
Issue: 2
Page: 629-634
Publish at: 2018-04-01

Biometrics Authentication of Fingerprint with Using Fingerprint Reader and Microcontroller Arduino

10.12928/telkomnika.v16i2.7572
Magdin; Constantine the Philosopher University in Nitra Martin , Koprda; Constantine the Philosopher University in Nitra Štefan , Ferenczy; Constantine the Philosopher University in Nitra Ľubor
The idea of security is as old as humanity itself. Between oldest methods of security were included simple mechanical locks whose authentication element was the key. At first, a universal–simple type, later unique for each lock. A long time had mechanical locks been the sole option for protection against unauthorized access. The boom of biometrics has come in the 20th century, and especially in recent years, biometrics is much expanded in the various areas of our life. Opposite of traditional security methods such as passwords, access cards, and hardware keys, it offers many benefits. The main benefits are the uniqueness and the impossibility of their loss. The main benefits are the uniqueness and the impossibility of their loss. Therefore we focussed in this paper on the the design of low cost biometric fingerprint system and subsequent implementation of this system in praxtise. Our main goal was to create a system that is capable of recognizing fingerprints from a user and then processing them. The main part of this system is the microcontroller Arduino Yun with an external interface to the scan of the fingerprint with a name Adafruit R305 (special reader). This microcontroller communicates with the external database, which ensures the exchange of data between Arduino Yun and user application. This application was created for (currently) most widespread mobile operating system-Android.
Volume: 16
Issue: 2
Page: 755-765
Publish at: 2018-04-01

Effects of Inter-Element Spacing and Number of Elements on Planar Array Antenna Characteristics

10.11591/ijeecs.v10.i1.pp230-240
Noor Hidayah Muhamad Adnan , Islam Md. Rafiqul , AHM Zahirul Alam
Planar array antenna is seen as one of the innovative solutions of massive MIMO and 5G networks since they provide directive beams. In this paper, planar array antenna with square and rectangular arrangements based on 2 x 2 antenna elements as one subarray was proposed. Then, array factor for the the planar array antenna with up to 64 antenna elements was calculated to analyze the effects of inter-element spacing and number of elements on the antenna characteristics. Higher values of inter-element spacing contributed to higher number of side lobes, narrower main lobe, higher directivity and lower half power beamwidth (HPBW). Inter-element spacing equals to 0.5λ was found to be the most suitable value for planar array antenna design based on the analysis. Meanwhile, higher number of antenna elements increased the value of directivity of the planar array with narrower HPBW. Therefore, there is a tradeoff between directivity and HPBW in designing planar array antenna for massive MIMO application.        
Volume: 10
Issue: 1
Page: 230-240
Publish at: 2018-04-01

Kalman Filter Estimation of Impedance Parameters for Medium Transmission Line

10.12928/telkomnika.v16i2.9026
Siti Nur Aishah; Universiti Malaysia Pahangs Mohd Amin , Hamzah; Universiti Malaysia Pahang Ahmad , Mohd Rusllim; Universiti Malaysia Pahang Mohamed , Mohd Mawardi; Universiti Malaysia Pahang Saari , Omar; Universiti Malaysia Pahang Aliman
Accurate knowledge of impedance parameters in transmission line helps to improve the system efficiency and performance. Nowadays, the estimation of impedance parameters in transmission line has become possible with the availability of computational method. This paper aims to develop Kalman filter model by using Matlab simulink to estimate accurate values of resistance (R), reactance (X), and susceptance (B) in medium transmission line. The accuracy of the parameters can be improved by reducing the unknown errors in the system. To demonstrate the effectiveness of the Kalman filter method, a case study of simulated medium transmission line is presented and comparison between Kalman Filter (KF) and Linear Least Square (LLS) method is also considered to evaluate their performances.
Volume: 16
Issue: 2
Page: 900-908
Publish at: 2018-04-01

Miniaturization of Broadband Wilkinson Power Dividers

10.11591/ijeecs.v10.i1.pp241-247
Nadera Najib , Kok Yeow You , Chia Yew Lee , Mohamad Ngasri Dimon , Nor Hisham Khamis
This paper proposed three modified Wilkinson power dividers in order to achieve a size reduction and a wide bandwidth. The first structure presented the power divider using compact folded step impedance transmission lines rather than the uniform microstrip line design for operating center frequency of 3 GHz. The second structure showed the power divider with delta-stub for 2.4 GHz. Finally, the third modified structure introduced the two-section Wilkinson power divider using series-delta stub for center frequency of 2.4 GHz as well. The study managed to get an overall dimension of 15 mm × 9.5 mm for the first proposed design achieving a reduction of 75.6 % and fractional bandwidth of 133 %. For the second proposed structure, the size was 15 mm × 15 mm with a reduction of 56 % and fractional bandwidth of 56 %.  While the third design size was 17 mm × 15 mm with a reduction of 63.6 % and the structure achieved a broadband bandwidth with fractional bandwidth of 220 %.  The proposed power dividers used RT/duroid 5880 substrate with a thickness of 0.38 mm. Simulation and measurement results indicated that the modified power dividers showed equal power division, good phase balance, high isolation between output ports, and good return loss better than -12 dB covering the operating frequency range.
Volume: 10
Issue: 1
Page: 241-247
Publish at: 2018-04-01

Design of Negative Resistance Oscillator with Rocord Low Phase Noise

10.12928/telkomnika.v16i2.6999
Ayoub; University Complex Malki , Jamal; University Complex Zbitou , Larbi; University Complex El Abdellaoui , Mohamed; Microwave group ESEO Angers Latrach , Abdelali; University Complex Tajmouati , Ahmed; University Complex Errkik
The aim of this paper is to use a new design of a negative resistance microwave oscillator in order to fabricate oscillator with very good performance in terms of output power, efficiency, stability and phase noise. In this study the new concept of oscillator using distributed resonator and micro-strip circuit elements improve performances of our structure. A micro-strip microwave oscillator with low phase noise based on an NPN silicon planar epitaxial transistor has been designed, fabricated, and characterized. In this design, each step has been conducted by using Advanced Design System (ADS) and following a theoretical study which enable to optimize the different performances of the whole circuit. The oscillator produce a sinusoidal signal with spectrum power of 12.25 dBm at 2.45 GHz into 50 Ω load when polarized at Vcc=15V with DC to RF efficiency of 16. The obtained phase noise of -120 dBc/Hz at 100 Hz offset is the result of the use of high Q factor resonator and the depth study of the parameters of the oscillator. Simulation and measurement results are in good agreement.
Volume: 16
Issue: 2
Page: 586-593
Publish at: 2018-04-01

Power Efficient Clock Distribuition for Switched Capacitor DC-DC Converters

10.11591/ijeecs.v10.i1.pp27-36
A. S. R. Murthy , Sridhar T.
In various VLSI based digital systems, on-chip interconnects have become the system bottleneck in state-of-the-art chips, limiting the performance of high-speed clock distributions and data communication devices in terms of propagation delay and power consumption. Increasing power requirements and power distribution to multi-core architectures is also posing a challenge to power distribution networks in the integrated circuits. Clock distribution networks for the switched capacitor converters becomes a non-trivial task and the increased interconnect lengths cause clock degradation and power dissipation. Therefore, this paper introduce low swing signaling schemes to decrease delay and power consumption. A comparative study presented of low voltage signaling schemes in terms of delay, power consumption and power delay product. Here, we have presented a power efficient signaling topology for driving the clocks to higher interconnect lengths.
Volume: 10
Issue: 1
Page: 27-36
Publish at: 2018-04-01

Implementation of Controlled Robot for Fire Detection and Extinguish to Closed Areas Based on Arduino

10.12928/telkomnika.v16i2.8197
Ihsan A.; Al-Esra'a University Taha , Hamzah M.; Al-Esra'a University Marhoon
The wireless control systems are taking a special importance in the recent years, where the wireless control system provide several advantages; including the disposal of the using wire and periodic maintenance of data transmission wires, in the science of robot wireless control unit is the main part of the fire treatment and extinguish robot system. The lives of firefighters exposed to the risk of death and Rima, therefore the use of remote control systems more secure is necessary. In this, paper a fire-extinguish robot used for extinguishing the fire in general and in treatment fires in the closed areas for protecting employees in the field of fire suppression from combustion, exposure or inhalation to the toxic gases. The basic idea of fire detection and treatment robot based on detect the fire by the wireless camera and flame sensor then suppression the fire by send command from mobile phone through Bluetooth connection to make water pump turn "ON", and the fire then extinguished.
Volume: 16
Issue: 2
Page: 654-664
Publish at: 2018-04-01

Task Scheduling in Heterogeneous Multiprocessor Environments – An Efficient ACO-Based Approach

10.11591/ijeecs.v10.i1.pp320-329
Nekiesha Edward , Jeffrey Elcock
In heterogeneous computing environments, finding optimized solutions continues to be one of the most important and yet, very challenging problems. Task scheduling in such environments is NP-hard, so efficient mapping of tasks to the processors remains one of the most critical issues to be tackled. For several types of applications, the task scheduling problem is crucial, and across the literature, a number of algorithms with several different approaches have been proposed. One such effective approach is known as Ant Colony Optimization (ACO). This popular optimization technique is inspired by the capabilities of ant colonies to find the shortest paths between their nests and food sources. Consequently, we propose an ACO-based algorithm, called rACS, as a solution to the task scheduling problem. Our algorithm utilizes pheromone and a priority-based heuristic, known as the upward rank value, as well as an insertion-based policy and a pheromone aging mechanism to guide the ants to high quality solutions. To evaluate the performance of our algorithm, we compared our algorithm with the ACS algorithm and the ACO-TMS algorithm using randomly generated directed acyclic graphs (DAGs). The simulation results indicated that our algorithm experienced comparable or even better performance, than the selected algorithms.
Volume: 10
Issue: 1
Page: 320-329
Publish at: 2018-04-01
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