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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of Electrical Engineering and Technology
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Journal DOI :
The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 8, Issue 6 - Nov 2013
Volume 8, Issue 5 - Sep 2013
Volume 8, Issue 4 - Jul 2013
Volume 8, Issue 3 - May 2013
Volume 8, Issue 2 - Mar 2013
Volume 8, Issue 1 - Jan 2013
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A New Battery Approach to Wind Generation System in Frequency Control Market
Nguyen, Minh Y. ; Nguyen, Dinh Hung ; Yoon, Yong Tae ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 667~674
DOI : 10.5370/JEET.2013.8.4.667
Wind power producers face many regulation costs in deregulated environment, which remarkably lowers the value of wind power in comparison with conventional sources. One of these costs is associated with the real-time variation of power output and being paid in frequency control market according to the variation band. This paper presents a new approach to coordination of battery energy storage in wind generation system for reducing the payment in frequency control market. The approach depends on the statistic data of wind generation and the prediction of frequency control market price to determine the optimal variation band which is then kept by the real-time charging and discharging of batteries, ultimately the minimum cost of frequency regulation can be obtained. The optimization problem is formulated as trade-off between the decrease in the regulation payment and the increase in the cost of using battery, and vice versus. The approach is applied to a study case and the results of simulation show its effectiveness.
Solving Mixed Strategy Nash-Cournot Equilibria under Generation and Transmission Constraints in Electricity Market
Lee, Kwang-Ho ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 675~685
DOI : 10.5370/JEET.2013.8.4.675
Generation capacities and transmission line constraints in a competitive electricity market make it troublesome to compute Nash Equilibrium (NE) for analyzing participants' strategic generation quantities. The NE can cause a mixed strategy NE rather than a pure strategy NE resulting in a more complicated computation of NE, especially in a multiplayer game. A two-level hierarchical optimization problem is used to model competition among multiple participants. There are difficulties in using a mathematical programming approach to solve a mixed strategy NE. This paper presents heuristics applied to the mathematical programming method for dealing with the constraints on generation capacities and transmission line flows. A new formulation based on the heuristics is provided with a set of linear and nonlinear equations, and an algorithm is suggested for using the heuristics and the newly-formulated equations.
Application of Opposition-based Differential Evolution Algorithm to Generation Expansion Planning Problem
Karthikeyan, K. ; Kannan, S. ; Baskar, S. ; Thangaraj, C. ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 686~693
DOI : 10.5370/JEET.2013.8.4.686
Generation Expansion Planning (GEP) is one of the most important decision-making activities in electric utilities. Least-cost GEP is to determine the minimum-cost capacity addition plan (i.e., the type and number of candidate plants) that meets forecasted demand within a pre specified reliability criterion over a planning horizon. In this paper, Differential Evolution (DE), and Opposition-based Differential Evolution (ODE) algorithms have been applied to the GEP problem. The original GEP problem has been modified by incorporating Virtual Mapping Procedure (VMP). The GEP problem of a synthetic test systems for 6-year, 14-year and 24-year planning horizons having five types of candidate units have been considered. The results have been compared with Dynamic Programming (DP) method. The ODE performs well and converges faster than DE.
A Novel Line Stability Index for Voltage Stability Analysis and Contingency Ranking in Power System Using Fuzzy Based Load Flow
Kanimozhi, R. ; Selvi, K. ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 694~703
DOI : 10.5370/JEET.2013.8.4.694
In electric power system, the line stability indices adopted in most of the instances laid stress on variation of reactive power than real power variation of the transmission line. In this paper, a proposal is made with the formulation of a New Voltage Stability Index (NVSI) which originates from the equation of a two bus network, neglecting the resistance of transmission line, resulting in appreciable variations in both real and reactive loading. The efficacy of the index and fuzzy based load flow are validated with IEEE 30 bus and Tamil Nadu Electricity Board (TNEB) 69 bus system, a practical system in India. The results could prove that the identification of weak bus and critical line in both systems is effectively done. The weak area of the practical system and the contingency ranking with overloading either line or generator outages are found by conducting contingency analysis using NVSI.
Reliability Modeling of Direct Current Power Feeding Systems for Green Data Center
Choi, Jung Yul ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 704~711
DOI : 10.5370/JEET.2013.8.4.704
Data center is an information hub and resource for information-centric society. Since data center houses hundreds to ten thousands servers, networking and communication equipment, and supporting systems energy saving is one of the hottest issues for green data center. Among several solutions for green data center this paper introduces higher voltage direct current (DC) power feeding system. Contrary to legacy alternating current (AC) power feeding system equipped with Uninterruptible Power Supply (UPS), higher voltage DC power feeding system is reported to be a more energy efficient and reliable solution for green data center thanks to less AC/DC and DC/AC conversions. Main focus of this paper is on reliability issue for reliable and continuous operation of higher voltage DC power feeding system. We present different types of configuration of the power feeding systems according to the level of reliability. We analyze the reliability of the power feeding systems based on M/M/1/N+1/N+1 queueing model. Operation of the power feeding system in case of failure is also presented.
Optimal Voltage Regulation Method for Distribution Systems with Distributed Generation Systems Using the Artificial Neural Networks
Kim, Byeong-Gi ; Rho, Dae-Seok ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 712~718
DOI : 10.5370/JEET.2013.8.4.712
With the development of industry and the improvement of living standards, better quality in power electric service is required more than ever before. This paper deals with the optimal algorithms for voltage regulation in the case where Distributed Storage and Generation (DSG) systems are operated in distribution systems. It is very difficult to handle the interconnection issues for proper voltage managements, because the randomness of the load variations and the irregular operation of DSG should be considered. This paper proposes the optimal on-line real time voltage regulation methods in power distribution systems interconnected with the DSG systems. In order to deliver suitable voltage to as many customers as possible, the optimal sending voltage should be decided by the effective voltage regulation method by using artificial neural networks to consider the rapid load variation and random operation characteristics of DSG systems. The simulation results from a case study show that the proposed method can be a practical tool for the voltage regulation in distribution systems including many DSG systems.
Probabilistic Assessment of Voltage Stability Margin in Presence of Wind Speed Correlation
Li, Hongxin ; Cai, DeFu ; Li, Yinhong ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 719~728
DOI : 10.5370/JEET.2013.8.4.719
Probabilistic assessment of voltage stability margin (VSM) with existence of correlated wind speeds is investigated. Nataf transformation is adopted to establish wind speed correlation (WSC) model. Based on the saddle-node bifurcation transversality condition equations and Monte Carlo simulation technique, probability distribution of VSM is determined. With correlation coefficients range low to high value, the effect of WSC on VSM is studied. In addition, two risk indexes are proposed and the possible threat caused by WSC is evaluated from the viewpoint of risk analysis. Experimental results show that the presence of correlated wind speeds is harmful to safe and stable operation of a power system as far as voltage stability is concerned. The achievement of this paper gives a detailed elaboration about the influence of WSC on voltage stability and provides a potentially effective analytical tool for modern power system with large-scale wind power sources integration.
Phase Shift Analysis and Phase Identification for Distribution System with 3-Phase Unbalanced Constant Current Loads
Byun, Hee-Jung ; Shon, Sugoog ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 729~736
DOI : 10.5370/JEET.2013.8.4.729
Power grids are large complicated networks in use around. An absolute phase value for a particular unknown-phase line at a local site should be identified for the operation and management of a 3-phase distribution network. The phase shift for a specific point in the line, as compared with a phase reference point at a substation, must be within a range of
for correct identification. However, the phase shift at a particular point can fluctuate depending on the line constants, transformer wiring method, line length, and line amperage, etc. Conducted in this study is a theoretical formulation for the determination of phase at a specific point in the line, Simulink modeling, and analysis for a distribution network. In particular, through evaluating the effects of unbalanced current loads, the limitations of the present phase identification methods are described.
The Advanced Voltage Regulation Method for ULTC in Distribution Systems with DG
Kim, Mi-Young ; Song, Yong-Un ; Kim, Kyung-Hwa ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 737~743
DOI : 10.5370/JEET.2013.8.4.737
The small-scaled onsite generators such as photovoltaic power, wind power, biomass and fuel cell belong to decarbonization techniques. In general, these generators tend to be connected to utility systems, and they are called distributed generations (DGs) compared with conventional centralized power plants. However, DGs may impact on stabilization of utility systems, which gets utility into trouble. In order to reduce utility's burdens (e.g., investment for facilities reinforcement) and accelerate DG introduction, the advanced operation algorithms under the existing utility systems are urgently needed. This paper presents the advanced voltage regulation method in power systems since the sending voltage of voltage regulators has been played a decisive role restricting maximum installable DG capacity (MaxC_DG). For the proposed voltage regulation method, the difference from existing voltage regulation method is explained and the detailed concept is introduced in this paper. MaxC_DG estimation through case studies based on Korean model network verifies the superiority of the proposed method.
Multi Area Economic Dispatch using Secant Method
Sudhakar, A.V.V. ; Chandram, Karri ; Jayalaxmi, A. ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 744~751
DOI : 10.5370/JEET.2013.8.4.744
In this paper, Secant method is proposed to solve multi area economic dispatch (MAED) problem. Generator limits of all generators in each area are calculated at given area power demands plus export (or import) using secant method and the generator limits of all generators are modified as modified generator limits. Central economic dispatch (CED) problem is used to determine the output powers of all generators. Here, Secant method is applied to solve the CED problem. The proposed approach has been tested on two-area (two generators in each area) system and four-area (four generators in each area) system. It is observed from various cases that the proposed approach provides optimally best solution in terms of cost with tie line loss with less computational burden.
Fault Diagnosis and Fault-Tolerant Control of DC-link Voltage Sensor for Two-stage Three-Phase Grid-Connected PV Inverters
Kim, Gwang-Seob ; Lee, Kyo-Beum ; Lee, Dong-Choon ; Kim, Jang-Mok ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 752~759
DOI : 10.5370/JEET.2013.8.4.752
This paper proposes a method for fault diagnosis and fault-tolerant control of DC-link voltage sensor for two-stage three-phase grid-connected PV inverters. Generally, the front-end DC-DC boost converter tracks the maximum power point (MPP) of PV array and the rear-end DC-AC inverter is used to generate a sinusoidal output current and keep the DC-link voltage constant. In this system, a sensor is essential for power conversion. A sensor fault is detected when there is an error between the sensed and estimated values, which are obtained from a DC-link voltage sensorless algorithm. Fault-tolerant control is achieved by using the estimated values. A deadbeat current controller is used to meet the dynamic characteristic of the proposed algorithm. The proposed algorithm is validated by simulation and experiment results.
Modeling, Simulation and Fault Diagnosis of IPFC using PEMFC for High Power Applications
Darly, S.S. ; Vanaja Ranjan, P. ; Justus Rabi, B. ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 760~765
DOI : 10.5370/JEET.2013.8.4.760
An Interline Power Flow Controller (IPFC) is a converter based controller which compensates and balance the power flow among multi-lines within the same corridor of the multi-line subsystem. The Interline Power Flow Controller consists of a voltage source converter based Flexible AC Transmission System (FACTS) controller for series compensation. The reactive voltage injected by individual Voltage Source Converter (VSC) can be controlled to regulate active power flow in the respective line in which one VSC regulates the DC voltage, the other one controls the reactive power flows in the lines by injecting series active voltage. In this paper, a circuit model for IPFC is developed and simulation of interline power flow controller is done using the proposed circuit model. Simulation is done using MATLAB Simulink and PSPICE. The results obtained by MATLAB are compared with the results obtained by PSPICE and compared with theoretical values.
Control of Radial Force in Double Stator Type Bearingless Switched Reluctance Motor
Peng, Wei ; Xu, Zhenyao ; Lee, Dong-Hee ; Ahn, Jin-Woo ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 766~772
DOI : 10.5370/JEET.2013.8.4.766
Modeling and control of radial force in the double stator type bearingless switched reluctance motor (BLSRM) is researched. The rotational torque is controlled independently from the radial force control. And the radial force is constant which is independent from the rotor position. In order to realize steady suspension, analytical models of torque and radial force for the proposed structure are derived. Meanwhile, in order to realize steady suspension, control scheme for proposed BLSRM is proposed. In the control method, the radial force can be controlled in arbitrary direction and magnitude by selecting some combinations of radial force windings. The validities of structure and control method are verified by the experimental results.
An Efficient Pulse Width Measurement Method using Multiphase Clock Signals for Capacitive Touch Switches
Seong, Kwang-Su ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 773~779
DOI : 10.5370/JEET.2013.8.4.773
We propose an efficient method to measure a pulse width using multiphase clock signals generated from a ring oscillator. These clocks, which have the same frequency and are evenly spaced, give multiple rising edges within a clock cycle. Thus, it is possible to measure a pulse width more accurately than with existing single clock-based methods. The proposed method is applied to a capacitive touch switch. Experimental results show that the capacitive touch switch with the proposed method gives a 118 fF resolution, which is 6.4 times higher than that of the touch switch with a single clock-based pulse width measurement method.
A Second-Order Design Sensitivity-Assisted Monte Carlo Simulation Method for Reliability Evaluation of the Electromagnetic Devices
Ren, Ziyan ; Koh, Chang-Seop ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 780~786
DOI : 10.5370/JEET.2013.8.4.780
In the reliability-based design optimization of electromagnetic devices, the accurate and efficient reliability assessment method is very essential. The first-order sensitivity-assisted Monte Carlo Simulation is proposed in the former research. In order to improve its accuracy for wide application, in this paper, the second-order sensitivity analysis is presented by using the hybrid direct differentiation-adjoint variable method incorporated with the finite element method. By combining the second-order sensitivity with the Monte Carlo Simulation method, the second-order sensitivity-assisted Monte Carlo Simulation algorithm is proposed to implement reliability calculation. Through application to one superconductor magnetic energy storage system, its accuracy is validated by comparing calculation results with other methods.
Parameter Design and Power Flow Control of Energy Recovery Power Accumulator Battery Pack Testing System
Bo, Long ; Chong, Kil To ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 787~798
DOI : 10.5370/JEET.2013.8.4.787
This paper proposes a special power circuit topology and its corresponding control strategy for an energy recovery power accumulator battery pack testing system (PABPTS), which is particularly used in electric vehicles. Firstly, operation principle and related parameter design for the system are illustrated. Secondly, control strategy of the composite power converter for PABPTS is analyzed in detail. The improved scheme includes a high accuracy charge and discharge current closed loop. active power reference for the grid-side inverter is provided by the result of multiplication between battery pack terminal voltage and test current. Simulation and experimental results demonstrate that the proposed scheme could not only satisfy the requirements for PABPTS with wide-range current test, but also could recover the discharging energy to the power grid with high efficiency.
Proposed Equivalent Circuit and Parameter Identification Method for Electro-Magnetic Resonance Based Wireless Power Transfer
Kawamura, Atsuo ; Kim, Tae-Woong ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 799~807
DOI : 10.5370/JEET.2013.8.4.799
The proper equivalent circuit is newly presented for electro-magnetic resonance based wireless power transfer. Based on the proposed equivalent circuit of open-ended helical antennas, the parameter identification of helical antennas can be well derived for highly efficient wireless power transfer. The well-established equivalent circuit in high frequency ranges is developed for analyzing a resonance enhanced-electromagnetic coupling helical antennas and the unknown parameters for helical antennas are identified by experiments. The effectiveness based on the proposed equivalent circuit is verified through experiments.
Design and Analysis of Electrical Properties of a Multilayer Ceramic Capacitor Module for DC-Link of Hybrid Electric Vehicles
Yoon, Jung-Rag ; Moon, Bong Hwa ; Lee, Heun Young ; Jeong, Dae Yong ; Rhie, Dong Hee ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 808~812
DOI : 10.5370/JEET.2013.8.4.808
Multilayer capacitors with high ripple current and high capacitance were manufactured. The electrical properties of these capacitors were characterized for potential application for DC-link capacitors in hybrid electric vehicle inverters. Internal electrode structures were designed to achieve high capacitance and reliability. A single multilayer capacitor showed
of capacitance, 0.65% of dielectric loss, and 1450 V to 1650 V of dielectric breakdown voltage depending on the design of the internal electrode. The capacitor module designed with several multilayer capacitors gave a total capacitance of
, which is enough for hybrid electric vehicles. In particular, an equivalent series resistance of
or less will result in 60
, thereby reaching the allowed ripple current for hybrid electric vehicles.
Development and Application of Distributed Multilayer On-line Monitoring System for High Voltage Vacuum Circuit Breaker
Mei, Fei ; Mei, Jun ; Zheng, Jianyong ; Wang, Yiping ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 813~823
DOI : 10.5370/JEET.2013.8.4.813
On-line monitoring system is important for high voltage vacuum circuit breakers (HVCBs) in operation condition assessment and fault diagnosis. A distributed multilayer system with client/server architecture is developed on rated voltage 10kV HVCB with spring operating mechanism. It can collect data when HVCB switches, calculate the necessary parameters, show the operation conditions and provide abundant information for fault diagnosis. Ensemble empirical mode decomposition (EEMD) is used to detect the singular point which is regarded as the contact moment. This method has been applied to on-line monitoring system successfully and its satisfactory effect has been proved through experiments. SVM and FCM are both effective methods for fault diagnosis. A combinative algorithm is designed to judge the faults of HVCB's operating mechanism. The system's precision and stability are confirmed by field tests.
Considering on the Ground Reflection Effect on the Electromagnetic Fields due to Lightning Channel
Izadi, Mahdi ; Ab Kadir, Mohd Zainal Abidin ; Hajikhani, Maryam ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 824~831
DOI : 10.5370/JEET.2013.8.4.824
Lightning electromagnetic fields are important issues for the evaluation of lightning induced overvoltage on power lines and for setting the appropriate protection level for power networks. Such electromagnetic fields are strongly dependent on lightning return stroke currents at different heights along the lightning channel. On the other hand, the ground reflection factor due to the difference between the return stroke channel impedance and the equivalent ground impedance at channel base can have an effect on the shape of the return stroke currents by entering additional reflected currents into the channel. In this paper, the effect of the ground reflection factor on the return stroke currents at different heights along a channel and the electromagnetic fields associated with the lightning channel at close distances are considered. Moreover, the behavior of the electromagnetic fields versus the reflection factor changes and the radial distance changes are considered and the results are discussed accordingly. The results illustrate that the reflection factor has a direct relationship with the values of the electromagnetic fields while this is usually ignored in earlier studies.
Partial Discharge Simulation and Analysis Based on Experiment in Underground Distribution Power Cables
Jung, Chae-Kyun ; Kim, Jeong-Tae ; Lee, Jong-Beom ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 832~839
DOI : 10.5370/JEET.2013.8.4.832
This paper describes the simulation and experiment for partial discharge (PD) pulse propagation in 22.9kV CNCV power cables. To investigate the propagation characteristics of PD, experiments are carried out by injecting the PD pulse in 100m-long 60
CNCV cable in the laboratory. The characteristics of PD are also simulated using EMTP to investigate and analyze PD in the same cable. By comparing the simulation and test results, parameter permittivity is recalculated by considering semiconducting screen in the process of simulation and analysis of PD. After it is proved that simulation results and test results are almost similar in the laboratory, extensive simulations are performed to analyse various PD characteristics such as propagation velocity, attenuation, etc. in 60
CNCV cables. Authors are confident that results obtained in this paper will be used as important technical materials to detect and investigate PD generated in transmission and distribution power cables.
Statistical Analysis of Electrical Tree Inception Voltage, Breakdown Voltage and Tree Breakdown Time Data of Unsaturated Polyester Resin
Ahmad, Mohd Hafizi ; Bashir, Nouruddeen ; Ahmad, Hussein ; Piah, Mohamed Afendi Mohamed ; Abdul-Malek, Zulkurnain ; Yusof, Fadhilah ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 840~849
DOI : 10.5370/JEET.2013.8.4.840
This paper presents a statistical approach to analyze electrical tree inception voltage, electrical tree breakdown voltage and tree breakdown time of unsaturated polyester resin subjected to AC voltage. The aim of this work was to show that Weibull and lognormal distribution may not be the most suitable distributions for analysis of electrical treeing data. In this paper, an investigation of statistical distributions of electrical tree inception voltage, electrical tree breakdown voltage and breakdown time data was performed on 108 leaf-like specimen samples. Revelations from the test results showed that Johnson SB distribution is the best fit for electrical tree inception voltage and tree breakdown time data while electrical tree breakdown voltage data is best suited with Wakeby distribution. The fitting step was performed by means of Anderson-Darling (AD) Goodness-of-fit test (GOF). Based on the fitting results of tree inception voltage, tree breakdown time and tree breakdown voltage data, Johnson SB and Wakeby exhibit the lowest error value respectively compared to Weibull and lognormal.
A Study on Improved Isolation of Indoor Repeating Antenna using Metamaterial Absorber for WCDMA System
Kim, Hyoungjun ; Moon, Yong ; Seo, Chulhun ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 850~855
DOI : 10.5370/JEET.2013.8.4.850
This paper proposes a novel design for a compact, high-isolation WCDMA indoor repeater antenna. The proposed antenna consists of a patch antenna and metamaterial absorber. The required WCDMA bandwidth is obtained by utilizing the coupling between the main and the parasitic patches. In addition, high isolation is achieved using the metamaterial absorber, which has an absorption of about 98% at 2.1 GHz. Overall, the proposed antenna has a gain of over 7 dBi, a Voltage Standing Wave Ratio (VSWR) of less than 2, more than 85 dB of isolation between the service and donor antennas over the WCDMA band and a total volume of the proposed antenna only
Cavity-backed Two-arm Spiral Antenna with a Ring-shaped Absorber for Partial Discharge Diagnosis
Kim, Han-Byul ; Hwang, Keum-Cheol ; Kim, Hyeong-Seok ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 856~862
DOI : 10.5370/JEET.2013.8.4.856
A cavity-backed two-arm spiral antenna for partial discharge diagnosis is presented. The proposed antenna consists of a two-arm Archimedean spiral, a tapered microstrip balun as spiral antenna feed, and a ring-shaped absorber-loaded cavity. The Archimedean spiral antenna is designed for the operating frequency band of 0.3 GHz to 1.5 GHz and fed by the tapered microstrip balun. The cavity is utilized to transform the bidirectional beam into a unidirectional beam, thereby enhancing gain. The ring-shaped absorber is stacked in the cavity to reduce the reflected waves from the cavity wall. The proposed antenna is designed and simulated using CST Microwave Studio. A prototype of the proposed antenna is likewise fabricated and tested. The measured radiation patterns are directional to the positive z-axis, and the measured peak gain is 8.13 dBi at a frequency of 1.1 GHz.
Adaptive Control of Pitch Angle of Wind Turbine using a Novel Strategy for Management of Mechanical Energy Generated by Turbine in Different Wind Velocities
Hayatdavudi, Mahdi ; Saeedimoghadam, Mojtaba ; Nabavi, Seyed M.H. ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 863~871
DOI : 10.5370/JEET.2013.8.4.863
Control of pitch angle of turbine blades is among the controlling methods in the wind turbines; this measure is taken for managing mechanical power generated by wind turbine in different wind velocities. Taking into account the high significance of the power generated by wind turbine and due to the fact that better performance of pitch angle is followed by better quality of turbine-generated power, it is therefore crucially important to optimize the performance of this controller. In the current paper, a PI controller is primarily used to control the pitch angle, and then another controller is designed and replaces PI controller through applying a new strategy i.e. alternating two ADALINE neural networks. According to simulation results, performance of controlling system improves in terms of response speed, response ripple, and ultimately, steady tracing error. The highly significant feature of the proposed intelligent controller is the considerable stability against variations of wind velocity and system parameters.
The Volume Measurement of Air Flowing through a Cross-section with PLC Using Trapezoidal Rule Method
Calik, Huseyin ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 872~878
DOI : 10.5370/JEET.2013.8.4.872
In industrial control systems, flow measurement is a very important issue. It is frequently needed to calculate how much total fluid or gas flows through a cross-section. Flow volume measurement tools use simple sampling or rectangle methods. Actually, flow volume measurement process is an integration process. For this reason, measurement systems using instantaneous sampling technique cause considerably high errors. In order to make more accurate flow measurement, numerical integration methods should be used. Literally, for numerical integration method, Rectangular, Trapezoidal, Simpson, Romberg and Gaussian Quadrature methods are suggested. Among these methods, trapezoidal rule method is quite easy to calculate and is notably more accurate and contains no restrictive conditions. Therefore, it is especially convenient for the portable flow volume measurement systems. In this study, the volume measurement of air which is flowing through a cross-section is achieved by using PLC ladder diagram. The measurements are done using two different approaches. Trapezoidal rule method is proposed to measure the flow sensor signal to minimize measurement errors due to the classical sampling method as a different approach. It is concluded that the trapezoidal rule method is more effective than the classical sampling.
3D Vision-Based Local Path Planning System of a Humanoid Robot for Obstacle Avoidance
Kang, Tae-Koo ; Lim, Myo-Taeg ; Park, Gwi-Tae ; Kim, Dong W. ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 879~888
DOI : 10.5370/JEET.2013.8.4.879
This paper addresses the vision based local path planning system for obstacle avoidance. To handle the obstacles which exist beyond the field of view (FOV), we propose a Panoramic Environment Map (PEM) using the MDGHM-SIFT algorithm. Moreover, we propose a Complexity Measure (CM) and Fuzzy logic-based Avoidance Motion Selection (FAMS) system to enable a humanoid robot to automatically decide its own direction and walking motion when avoiding an obstacle. The CM provides automation in deciding the direction of avoidance, whereas the FAMS system chooses the avoidance path and walking motion, based on environment conditions such as the size of the obstacle and the available space around it. The proposed system was applied to a humanoid robot that we designed. The results of the experiment show that the proposed method can be effectively applied to decide the avoidance direction and the walking motion of a humanoid robot.
A New Link-Based Single Tree Building Algorithm for Shortest Path Searching in an Urban Road Transportation Network
Suhng, Byung Munn ; Lee, Wangheon ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 889~898
DOI : 10.5370/JEET.2013.8.4.889
The shortest-path searching algorithm must not only find a global solution to the destination, but also solve a turn penalty problem (TPP) in an urban road transportation network (URTN). Although the Dijkstra algorithm (DA) as a representative node-based algorithm secures a global solution to the shortest path search (SPS) in the URTN by visiting all the possible paths to the destination, the DA does not solve the TPP and the slow execution speed problem (SEP) because it must search for the temporary minimum cost node. Potts and Oliver solved the TPP by modifying the visiting unit from a node to the link type of a tree-building algorithm like the DA. The Multi Tree Building Algorithm (MTBA), classified as a representative Link Based Algorithm (LBA), does not extricate the SEP because the MTBA must search many of the origin and destination links as well as the candidate links in order to find the SPS. In this paper, we propose a new Link-Based Single Tree Building Algorithm in order to reduce the SEP of the MTBA by applying the breaking rule to the LBA and also prove its usefulness by comparing the proposed with other algorithms such as the node-based DA and the link-based MTBA for the error rates and execution speeds.
Lateral Stability Control of Electric Vehicle Based On Disturbance Accommodating Kalman Filter using the Integration of Single Antenna GPS Receiver and Yaw Rate Sensor
Nguyen, Binh-Minh ; Wang, Yafei ; Fujimoto, Hiroshi ; Hori, Yoichi ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 899~910
DOI : 10.5370/JEET.2013.8.4.899
This paper presents a novel lateral stability control system for electric vehicle based on sideslip angle estimation through Kalman filter using the integration of a single antenna GPS receiver and yaw rate sensor. Using multi-rate measurements including yaw rate and course angle, time-varying parameters disappear from the measurement equation of the proposed Kalman filter. Accurate sideslip angle estimation is achieved by treating the combination of model uncertainties and external disturbances as extended states. Active front steering and direct yaw moment are integrated to manipulate sideslip angle and yaw rate of the vehicle. Instead of decoupling control design method, a new control scheme, "two-input two-output controller", is proposed. The extended states are utilized for disturbance rejection that improves the robustness of lateral stability control system. The effectiveness of the proposed methods is verified by computer simulations and experiments.
Advanced LDC Test Bed Using Energy Recovery Technique for HEVs
Kim, Yun-Sung ; Jung, Dong-Wook ; Lee, Byoung-Kuk ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 911~919
DOI : 10.5370/JEET.2013.8.4.911
This paper reports the development of test bed with the energy recovering technique using two-step boost converter. The device is utilized for LDC aging test of Hyundai Motor's LPI AVANTE HEV in mass production. The developed power recycle type test bed is designed as 1.5 kW class to test up to the maximum load power of LDC and is also designed to supply scant power supply up to 500 W after power recycle. The theoretical design analysis and operational characteristics analysis results of test bed are reported, and its practicality and reliability are verified through the test result. Also, the finally developed test bed confirms approximately 79~85 % energy saving effect compared to the usual traditional aging test system.
Development and Validation of an Energy Management System for an Electric Vehicle with a split Battery Storage System
Becker, Jan ; Schaeper, Christoph ; Rothgang, Susanne ; Sauer, Dirk Uwe ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 920~929
DOI : 10.5370/JEET.2013.8.4.920
Within the project 'e performance' supported by the German Ministry of Education and Research (BMBF) an electric vehicle, powered by two lithium-ion battery packs of different capacity and voltage has been developed. The required Energy Management System (EMS) in this system controls the current flows of both packs independently by means of two individual dc-dc converters. It acts as an intermediary between energy storage (battery management systems-BMS) and the drivetrain controller on the vehicle control unit (VCU) as well as the on-board charger. This paper describes the most important tasks of the EMS and its interfaces to the BMS and the VCU. To validate the algorithms before integrating them into the vehicle prototype, a detailed Matlab / Simulink-model was created in the project. Test procedures and results from the simulation as well as experiences and comparisons from the real car are presented at the end.
Motor Control of a Parallel Hybrid Electric Vehicle during Mode Change without an Integrated Starter Generator
Song, Minseok ; Oh, Joseph ; Choi, Seokhwan ; Kim, Yeonho ; Kim, Hyunsoo ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 930~937
DOI : 10.5370/JEET.2013.8.4.930
In this paper, a motor control algorithm for performing a mode change without an integrated starter generator (ISG) is suggested for the automatic transmission-based hybrid electric vehicle (HEV). Dynamic models of the HEV powertrains such as engine, motor, and mode clutch are derived for the transient state during the mode change, and the HEV performance simulator is developed. Using the HEV performance bench tester, the characteristics of the mode clutch torque are measured and the motor torque required for the mode clutch synchronization is determined. Based on the dynamic models and the mode clutch torque, a motor torque control algorithm is presented for mode changes, and motor control without the ISG is investigated and compared with the existing ISG control.
Suppression of Shaft Voltage by Rotor and Magnet Shape Design of IPM-Type High Voltage Motor
Kim, Kyung-Tae ; Cha, Sang-Hoon ; Hur, Jin ; Shim, Jae-Sun ; Kim, Byeong-Woo ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 938~944
DOI : 10.5370/JEET.2013.8.4.938
In this paper, we propose a method for suppressing shaft voltage by modifying the shape of the rotor and the permanent magnets in interior permanent magnet-type-high-voltage motors. Shaft voltage, which is induced by parasitic components and the leakage flux in motor-driven systems, adversely affects their bearings. In order to minimize shaft voltage, we designed a magnet rearrangement and rotor re-structuring of the motor. The shaft voltage suppression effect of the designed model was confirmed experimentally and by comparative finite element analysis.
Improved Analytical Modeling of a Ellipse Shape Permanent Magnet Rotor in Ultra-High-Speed Brushless DC motor for the Reduction of Torque Ripple
Sung, So-Young ; Jeong, Jae-Hoon ; Choi, Ji-Hwan ; Park, Hyung-Il ; Jang, Seok-Myeong ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 945~950
DOI : 10.5370/JEET.2013.8.4.945
This paper deals with the ellipse permanent magnet machines for the minimization of torque ripple based on electromagnetic field theory. On the basis of a magnetic vector potential and a two dimensional (2-D) polar system, analytical solutions for flux density due to permanent magnet (PM) and current are obtained. In particular, the analytical solutions for mathematical expressions of magnets with different circumferential thicknesses can be solved introducing improved magnetization modeling techniques. The analytical results are validated extensively be nonlinear finite element solutions, a reduction of torque ripple can be achieved.
A Controller Design for a Stability Improvement of an On-Board Battery Charger
Jeong, Hae-Gwang ; Lee, Kyo-Beum ;
Journal of Electrical Engineering and Technology, volume 8, issue 4, 2013, Pages 951~958
DOI : 10.5370/JEET.2013.8.4.951
This paper proposes the controller design for a stability improvement of an on-board battery charger. The system is comprised of a power factor correction (PFC) circuit and phase shift full-bridge DC-DC converter. The PFC circuit performs the control of the DC-link voltage and the input power factor. The DC-DC converter regulates the voltage and the current in the battery using the DC-link voltage. This paper proposes the design method of PI controller for the PFC circuit using a small signal model. The analysis and design of a type-three controller for the DC-DC converter is also presented. A simulation and experiment has been performed on the on-board battery charger and their results are presented to verify the validity of the proposed system.