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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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The Transactions of The Korean Institute of Electrical Engineers
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Journal DOI :
The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 59, Issue 12 - Dec 2010
Volume 59, Issue 11 - Nov 2010
Volume 59, Issue 10 - Oct 2010
Volume 59, Issue 9 - Sep 2010
Volume 59, Issue 8 - Aug 2010
Volume 59, Issue 7 - Jul 2010
Volume 59, Issue 6 - Jun 2010
Volume 59, Issue 5 - May 2010
Volume 59, Issue 4 - Apr 2010
Volume 59, Issue 3 - Mar 2010
Volume 59, Issue 2 - Feb 2010
Volume 59, Issue 1 - Jan 2010
Selecting the target year
A Study on the Outage Cost Assessment by using Macro Approach
Park, Young-Shin ; Jeon, Dong-Hoon ; Park, Jeong-Je ; Oh, Tae-Gon ; Cho, Kyeong-Hee ; Choi, Jae-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1703~1711
Electric power utilities are facing increasing uncertainties regarding the economic, political, societal, environmental constraints under they operate and plan their future systems. The utilities have to integrate consumers' interruption cost representing reliability worth of electricity into the process of determining the optimum investment level. In order to do so, the estimated outage cost must be included into quantitative index corresponding to system capital and operation investment cost to establish an optimal expansion plan. This paper is a study on the outage cost assessment by using macro approach for calculating IEAR(Interrupted Energy Assessment Rates) and the TRELSS(Transmission Reliability Evaluation for Large-Scale Systems) program was used to calculate EENS(Expected Energy Not Served).
Customer Classification Method Using Customer Attribute Information to Generate the Virtual Load Profile of non-Automatic Meter Reading Customer
Kim, Young-Il ; Ko, Jong-Min ; Song, Jae-Ju ; Choi, Hoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1712~1717
To analyze the load of distribution line, real LPs (Load Profile) of AMR (Automatic Meter Reading) customers and VLPs (Virtual Load Profile) of non-AMR customers are required. Accuracy of VLP is an important factor to improve the analysis performance. There are 2 kinds of methods to generate the VLP; one is using ALP (Average Load Profile) per each industrial code and PNN (Probability neural networks) algorithm; the other is using LSI (Load Shape Index) and C5.0 algorithm. In this paper, existing researches are studied, and new method is suggested. Each methods are compared the performance with same LP data of real high voltage customers.
Power Output Control of Wind Generation System Through Energy Storage System and STATCOM
Kim, Jong-Yul ; Park, June-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1718~1726
Utilization of renewable energy is becoming increaingly important from the viewpoints of environmental protection and conservation of fossil fuel. However, the generating power of renewable energy is always fluctuating due to the environmental status. This paper presents a scheme for supervisory control of wind generation system with the energy storage and STATCOM to reduce the power variation. In this paper, we especially concentrate on constant power output control of wind generation system. In order to achieve this purpose, the coordinated control strategy between different types of energy storage system and reactive power compensation device. The proposed control scheme has been validated by PSCAD/EMTDC simulation. As a result, the proposed scheme can handle the power output of wind generation system with a constant value.
A Study on the Determination of the Transient Performance for Protective Current Transformer
Kim, Dong-Su ; Park, Nam-Ok ; Kim, Chul-Hwan ; Ryu, Jae-Nam ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1727~1732
The Current transformer is classified measuring CT and protective CT for their purpose. The measuring CT is required to retain a specified accuracy over the normal range of load currents, but the protective CT must be capable of providing an adequate output over wide range of fault condition. Therefore, the protective CT must determine the transient performance during fault condition. This paper measured peak instantaneous error of the TPY class CT to determine the transient performance directly and indirectly and studied the test results.
A Study on the Optimal Operation of 2010 Summer Peak in Korea Power System
Lee, Sung-Moo ; Cho, Jong-Man ; Kim, Kyu-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1733~1740
KPX(Korea Power Exchange) predicts that summer peak load will be 70,700MW and system overload will be 150% from contingency analysis. This paper presents a method to operate power system at 2010 summer peak. about equipment variation, power system variation, analysis results of voltage stability, and the method to relief overload by comparing 2009 and 2010. Especially, transmission constraints to prevent global contingency in Korea power system and the role of SPS(Special Protection System) to prevent voltage collapse when fault occurs are introduced.
Development of Overload Evaluation System of Distribution Transformers using Real-Time Monitoring
Park, Chang-Ho ; Yun, Sang-Yun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1741~1747
The development of overload management systems for distribution transformers offers new opportunities for improving the reliability of distribution systems. It allows network planners to optimize the system resource utilization and investment cost. Such an improvement in the flexibility of the distribution network is only possible if the operator has more accurate knowledge of the realtime conditions of distribution transformers. In this paper, we present an improved overload decision system for distribution transformers using realtime monitoring data. Our study can be categorized into two parts: (a) improvement in the criteria for judging the overload conditions of distribution transformers and (b) development of an overload evaluation system using realtime monitoring data. In order to determine the overload criteria, overload experiments are performed on sample transformers; the results of these experiments are used to define the relationship between the transformer overload and the increase in the top-oil temperature. To verify the accuracy of the experimental results, field tests are performed using specially manufactured transformers, the loads and top-oil temperatures of which can be measured. For arriving at online overload decisions, we propose methods whereby the measured load curve can be converted into an overload characteristic curve and the overload time can be calculated for any load condition. The developed system is able to evaluate the overload for individual distribution transformers and calculate the losses using realtime monitoring data.
Steady and Transient State Analysis on Three Phase-in One Enclosure Type HTS Cable
Jang, Ju-Yeong ; Lee, Jong-Beom ; Kim, Yong-Kap ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1748~1753
This paper suggests an improved technique to establish the modeling regarding steady and transient state on three phase-in one cryostat type HTS(High Temperature Superconducting) cable. The proposed modeling is established using EMTP/ATPDraw and TACS and MODELS provided by that. It has higher accuracy than the conventional method, as the actual HTS cable is modelled. Steady and transient state analysis performed by EMTP/ATPDraw calculate the current of conductor, shield and former, respectively. In case of the transient state modeled quench state occurred by a single line-to-ground fault, current of conductor shield and former are also calculated, respectively. Especially, various fault resistances and angles are considered to improve the reliability during transient state analysis. Analysis results reveal that the proposed technique improves the accuracy of modeling.
The Assessment and Development of Protection Models in HVDC DC side
Lee, Seong-Doo ; Kim, Chan-Ki ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1754~1760
The HVDC system consists of ac side and dc side through thyristor valve. ac side protection is similar to conventional ac system protection schemes but dc side protection is different from ac side of HVDC system. AC system don't have controller but HVDC system has controller that controls and protects system from faults and disturbance. This paper show protectional function of HVDC dc side such as asymmetry protection, ac/dc differential protection, dc overvoltage, dc overcurrent protection. Protection models is developed using RTDS software and assessment of protection models is also performed by RTDS system.
A Study on Reclosing Decision on 154kV Combined Transmission Lines
Jung, Chae-Kyun ; Park, Hung-Sok ; Kang, Ji-Won ; Lee, Jong-Beom ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1761~1769
This paper describes switching surge analysis on reclosing decision in 154kV combined transmission line with power cables. Reclosing should be operated in combined transmission line based on the technical evaluation because of insulation problem of power cable section. If the surge strikes on power cable, the breakdown can occur at week point of cable insulation. Therefore the detailed analysis is required by considering several conditions such as length ratio of power cable, arrester, fault resistance, charging rate and grounding resistance, etc.. In addition, sheath voltage on IJ(Insulated Joint) is analyzed to confirm the protective level. Simulation is performed by EMTP/ATP. Analysis results show that reclosing can be operated without any special problem by the single line-to-ground fault with fault resistance of
occurred at the overhead transmission section in 154kV combined transmission lines and trap charge of 100% and 110%.
Enhancement of Rubber Gasket Material for Pole Transformer
Song, Dong-Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1770~1775
An acceleration life test for rubber gasket of pole transformer was performed. The Arrhenius method was applied as an accelerated degradation test. The failure mode was considered as an elongation, and the failure mechanism is counted as a heat. It is found that both the current material(NBR: Nitrile Butadiene Rubber) and recommended alternative material(HNBR: Hydrogenated Nitrile Butadiene Rubber) have the same Weibull distribution as a life characteristic. For life expectation 95% reliability level of characteristic life is used at using temperature. The test results for NBR and HNBR are 7.7 years and 28.0 years on
of using temperature, respectively.
Development of intelligent distribution automation system with the function of substation SCADA, power quality monitoring and diagnosis condition monitoring
Ha, B.N. ; Lee, S.W. ; Shin, C.H. ; Seo, I.Y. ; Jang, Mun-Jong ; Park, M.H. ; Yun, G.G. ; Song, I.K. ; Lee, B.S. ; Lee, J.C. ; NamKoong, W. ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1776~1786
Intelligent distribution automation system have total monitoring and control capability. The system covers substation, distribution network, distributed generations and customers at HV system. Various intelligent distribution facilities installed at distribution systems have voltage sensor, current sensor, aging monitoring sensor. Intelligent Feeder Remote Terminal Unit (IFRTU) tied to intelligent distribution facilities process information from facilities and it checks information of fault, power quality and aging of distribution facilities. The information is transmitted to master station through communication line. The master station have remote monitoring system covers substation, distribution network, distributed generations and customers. It also have various application programs that maintain optimal network operation by using information from on-site devices.
A Customer Interruption Cost Assessment Using Customer Survey
Chu, Cheol-Min ; Lee, Byung-Sung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1787~1791
This paper presents the survey results of the interruption on domestic customer, especially commercial, with primary focus on the cost are presented. General method utilized in quantifying the benefit of reliability on power system is to estimate the Customer Interruption Cost(CIC) associated with the electric service interruption. According to change the circumstance of electricity market by the deregulation and the introduction of new technology, reliable and accurate CIC is required for estimate the applied plan and technology under the circumstance. This paper presents the commercial customer interruption cost is estimated by the survey conducted by KEPCO in 2009. To collect the customer interruption data for calculation of CIC, the survey is conducted. The survey targeting commercial customer around the branch-offices under twelve regional headquarters of KEPCO was carried out.
Customer Interruption Cost Assessment of Domestic Residential Customer Using Customer Survey
Lee, Byung-Sung ; Chu, Cheol-Min ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1792~1796
In this paper, the survey results of the interruption on domestic residential customer with primary focus on the cost are presented. General method utilized in quantifying the benefit of reliability on power system is to estimate the Customer Interruption Cost(CIC) associated with the electric service interruption. According to change the circumstance of electricity market by the deregulation and the introduction of new technology, reliable and accurate CIC is required for estimate the applied plan and technology under the circumstance. This paper presents the residential customer interruption cost is estimated by the survey conducted by KEPCO in 2009. To collect the customer interruption data for calculation of CIC, the survey is conducted. The survey targeting residential customer around the branch-offices under twelve regional headquarters of KEPCO was carried out.
Design of a Fuzzy Speed Controller for a Permanent Magnet Synchronous Motor
Jung, Jin-Woo ; Kim, Tae-Heoung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1797~1802
This paper proposes a new fuzzy speed controller based on the Takagi-Sugeno fuzzy method to achieve a robust speed control of a permanent magnet synchronous motor(PMSM). The proposed controller requires the information of the load torque, so the second-order load torque observer is used to estimate it. The LMI condition is derived for the existence of the proposed fuzzy speed controller, and the LMI parameterization to calculate the gain matrices of the controller is provided. It is proven that the augmented control system including the fuzzy speed controller and the load torque observer is exponentially stable. To evaluate the performance of the proposed fuzzy speed controller, the simulation and experimental results are presented under motor parameter and load torque variations. Finally, it is clearly verified that the proposed control method can be used to accurately control the speed of a permanent magnet synchronous motor.
A Study on the Magnetic Field Intensity and BER from Wayside Device to On-board Device about the Train Speed in ATP System
Kim, Min-Seok ; Lee, Sang-Hyeok ; Lee, Jong-Woo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1803~1808
Electric railway system consists of rolling stock, track, signal and catenary system. ATP system in railway signaling system is the important one grasping the position and velocity of a train. The wayside device of ATP system is installed between rails. Recently, the research about increasing train speed has been developed in total departments of the railroad systems. The study on the information transmission between on-board device and wayside device is required for increasing the train speed in the ATP system. When the train speed is increased as to same transmission distance, the problem on information transmission occurs because the transmission time is decreased. In case that the transmission distance is extended, the transmission time is decreased with respect to the train speed. Therefore, we have to define the standard magnetic field intensity as to the train speed in order to transmit correctly telegram. In this paper, the transmission distance for the telegram is suggested on the basis of the train speed. Also, the standard magnetic field intensity from the wayside device to on-board device is proposed by using transmission distance regarding the train speed in the ERTMS/ETCS system by using Matlab program. Also, BER according to the train speed is presented by calculating electric field intensity from the magnetic field intensity.
An Improved High-Resolution Rotor Position Estimation Using Gain Scheduled Speed Observer in PMSM Drives with Hall-Effect Position Sensors
Kim, Sam-Young ; Byun, Hang-Gil ; Ko, Bong-Jin ; Park, Seung-Yub ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1809~1815
This paper presents an improved method for high-resolution rotor position estimation in the permanent magnet synchronous motor (PMSM) drives with low-resolution Hall-effect sensors. The proposed method adopts a gain-scheduled full-order speed observer. Since the quantized position signal, which is obtained from Hall-effect sensors, is basically used as the input of the observer, the sixth-order harmonics are essentially included in the estimated position. To eliminate the harmonic components, the quantized position is linearized by a linear extrapolation based on the estimated average speed and futhermore the speed-depentent observer gain scheduling strategy is developed. The observer gain is also scheduled by considering the motor acceleration to improve the dynamic performance according to the changes of the motor speed and load. Several experiments are performed for 800W PMSM drive and the results demonstrate the effectiveness of the proposed method.
A Train Performance Simulation using Simulink for Generating Energy-efficient Speed Profiles
Kang, Moon-Ho ; Han, Moon-Seob ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1816~1822
In this research TPS (Train Performance Simulation) blocks are designed using Simulink and applied to generate speed profiles for energy-efficient train operation. With a train operation mode of maximum powering, coasting, and maximum breaking, a breaking point is calculated from forward-backward running profiles. Then, GA (Genetic Algorithm) is used to solve a running time constraint, and a coasting point is produced from the searching process of GA. With the breaking point and the coasting point a speed profile is plotted. Train performance under a speed limit and gradient variations is simulated and resultant speed profiles are analyzed.
Development of Automatic Tracking Control Algorithm for Efficiency Improvement of PV Generation
Choi, Jung-Sik ; Ko, Jae-Sub ; Chung, Dong-Hwa ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1823~1831
This paper proposes an automatic tracking control algorithm for efficiency improvement of photovoltaic generation. Increasing the power of PV systems should improve the efficiency of solar cells or the power condition system. The normal alignment of the PV module always have to run perpendicular to the sun's rays. The solar tracking system, able to improve the efficiency of the PV system, was initiated by applying that to the PV power plant. The tracking system of conventional PV power plant has been studied with regard to the tracking accuracy of the solar cells. Power generation efficiency were increased by aligning the cells for maximum exposure to the sun's rays. Using a perpendicular position facilitated optimum condition. However, there is a problem about the reliability of tracking systems unable to not track the sun correctly during environmental variations. Therefore, a novel control algorithm needs to improve the generation efficiency of the PV systems and reduce the loss of generation. This control algorithm is the proposed automatic tracking algorithm in this paper. Automatic tracking control is combined the sensor and program method for robust control in environment changing condition. This tracking system includes the insolation, rain sensor and anemometer for climate environment changing. Proposed algorithm in this paper, is compared to performance of conventional tracking control algorithm in variative insolation condition. And prove the validity of proposed algorithm through the experimental data.
Analyses on Electrical-Mechanical Characteristics of Environment-friendly Transformer Insulating Material by Accelerated Thermal Aging
Shim, Myeong-Seop ; An, Jung-Sik ; Choi, Sun-Ho ; Jeong, Jung-Il ; Lee, Tae-Ho ; Huh, Chang-Su ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1832~1838
Aging of transformer insulating material in natural ester insulating oil is compared to that in conventional transformer oil. Aging of insulating paper and insulating oil have been studied by performing accelerated thermal aging test. Sealed aging test vessels containing cooper, laminated core, Kraft paper and insulating oil(natural oil or mineral oil) were aged at
for 500, 1000, 1500 and 2000 hours. Insulating oils after aging are investigated with total acid number, breakdown voltage and viscosity. Also, degradation of insulating paper after aging is determined using breakdown voltage and mechanical strength. Accelerated aging studies demonstrate a slower aging rate for natural ester insulating oil compared to the rate for conventional mineral oil.
Design and Implementation of Power Management Circuit for Semi-active RFID Tags
Kim, Yeong-Kyo ; Yi, Kyeon-Gil ; Cho, Sung-Kyo ; Nam, Ki-Hun ; Kim, Shi-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1839~1844
A power management controller circuit with switched capacitor mode down regulator and battery charger block for semi-active RFID tags was proposed and fabricated. The main purposes of the proposed switched capacitor mode down regulator and battery charger block are to reduce standby current and to provide a self-controlled thin film battery charger by detecting the received RF power, respectively. Fabricated chip area is
and measured standby current was about
. To further reduction of standby current, a wake-up circuit has to be included in the power management controller.
Buck-Boost DC to DC Converter for Thermoelectric Generator with Constant Output Voltage
Cho, Sung-Kyu ; Park, Soon-Seo ; Kim, Ji-Gon ; Nam, Ki-Hun ; Kim, Shi-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1845~1849
We have proposed and fabricated a Buck-Boost DC to DC Converter for Thermoelectric generator (TEG) with constant output voltage suitable for battery chargers or constant voltage supplies in the range of several watt. The experimental and simulation results have shown that the proposed method allows stable operation with maximum 86% power transfer efficiency. The proposed circuit has a merit in cost and miniaturization of a system compared to conventional MPPT algorithms, because the proposed method adopts only analog circuit without DSP or micro controller unit for calculating peak power point by iterative methods.
Ultra fast Marx Generator of N
Mixture Gas based on Research Output Characteristics
Doo, Jin-Suk ; Han, Seung-Moon ; Huh, Chang-Su ; Choi, Jin-Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1850~1855
The application field of the pulse power is very wide. Recently, Pulse power technologies take a large place in several applications. Then, many civil and military applications proceed. Marx generator is widely used in high voltage applications. Marx generator is widely used in high voltage applications, such as eletromagnetic wave and power lasers. This paper, we described about the high voltage pulse generator. A compact size high voltage pulse generator with nanosecnd rise time has been fabricated and investigated experimentally. The marx generator has 2 stages. Each stage was constructed one charging capacitor, two electrodes and one charging resistor. A inductance structure is used in order to improve the switching performances fo the whole generator. The experiments of rise time in pure gas and mixtures of gases were described. We tested the Marx generator at different insulation gas. the results show that the dielectric strength of the
mixture was significantly increased compared with pure nitrogen gas. The experimental results show that the rise time characteristics of the Marx generator can be controlled through varying insulation gas.
Characteristics of the Current Density Induced Inside a Worker Near a Neutral Ground Reactor
Min, Suk-Won ; Lee, Seung-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1856~1861
To reduce a high fault current, neutral ground reactors (NGR) were installed in the Korean substation. Current with several harmonic components flows in a NGR due to load unbalance in normal steady state and magnetic fields with several harmonic components are also generated around a NGR. As results of study, we found magnetic fields around a NGR in Korean substation included two harmonics, 180Hz and 540Hz. Magnetic fields of 180 Hz increased 3 times more current density inside a worker near a NGR than same magnitude magnetic fields of 60 Hz. We know a worker near a NGR may not meet ICNIRP guideline of 10(mA/
) due to several harmonic components.
Basic Rotation Characteristics and Energy Efficiencies of a Blade-Type Corona Motor
Jung, Jae-Seung ; Moon, Jae-Duk ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1862~1868
A corona motor, as one of a powerful cooling means of microelectronic devices, has been employed because of its very simple structure of no coils and no brushes. In this paper, the effect of polarity of applied voltage and the number of blade corona electrodes on the fundamental properties of rotation of the motor was investigated. The I-V and rotation characteristics of the blade corona electrode were significantly different from the different polarities of applied voltages and the blade corona electrode numbers, due to the different space charge effect resulted by the different migration mobility of the positive and negative ions generated near the blade corona electrode tip of the rotor of the motor. The rotation speed of the motor was influenced significantly by the polarity of corona discharge, the number of blades, and mass of rotor. At the same corona current, an effective rotation can be obtained with the positive corona caused by the lower ion mobility. On the other hand, the higher rotation speed can be obtained with the negative corona resulted from its higher corona current. The highest rotation speed and energy efficiency can be obtained with the rotor having 4 blades.
Review on the Relationship of Dissolved Gas Analysis and Internal Inspection of Transformer
Park, Hyun-Joo ; Nam, Chang-Hyun ; Jung, Nyun-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1869~1873
For reliable operation of oil-filled electrical equipment, monitoring and maintenance of insulating oil is essential. Dissolved gas analysis(DGA) is widely used for monitoring faults in high voltage electrical equipment in service. Therefore, oil analysis should be monitored regularly during its service life. KEPCO has investigated thousands of dissolved gas analysis data since 1985, and conducted studies on the relationship of gas in oil analysis and internal inspection results of transformer. As the results, KEPCO revised criteria for transformer diagnosis and has applied it since 2008. Almost of 100 cases of internal inspection results since 2001 have been investigated. This paper presents the correlation of the fault-identifying gases with faults found in actual transformers and how should we approach to internal inspection of transformer by dissolved gas analysis.
Stochastic Error Compensation Method for RDOA Based Target Localization in Sensor Network
Choi, Ga-Hyoung ; Ra, Won-Sang ; Park, Jin-Bae ; Yoon, Tae-Sung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1874~1881
A recursive linear stochastic error compensation algorithm is newly proposed for target localization in sensor network which provides range difference of arrival(RDOA) measurements. Target localization with RDOA is a well-known nonlinear estimation problem. Since it can not solve with a closed-form solution, the numerical methods sensitive to initial guess are often used before. As an alternative solution, a pseudo-linear estimation scheme has been used but the auto-correlation of measurement noise still causes unacceptable estimation errors under low SNR conditions. To overcome these problems, a stochastic error compensation method is applied for the target localization problem under the assumption that a priori stochastic information of RDOA measurement noise is available. Apart from the existing methods, the proposed linear target localization scheme can recursively compute the target position estimate which converges to true position in probability. In addition, it is remarked that the suggested algorithm has a structural reconciliation with the existing one such as linear correction least squares(LCLS) estimator. Through the computer simulations, it is demonstrated that the proposed method shows better performance than the LCLS method and guarantees fast and reliable convergence characteristic compared to the nonlinear method.
Online Fault Diagnosis of Motor Using Electric Signatures
Kim, Lark-Kyo ; Lim, Jung-Hwan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1882~1888
It is widely known that ESA(Electric Signature Analysis) method is very useful one for fault diagnosis of an induction motor. Online fault diagnosis system of induction motors using LabVIEW is proposed to detect the fault of broken rotor bars and shorted turns in stator. This system is not model-based system of induction motor but LabVIEW-based fault diagnosis system using FFT spectrum of stator current in faulty motor without estimating of motor parameters. FFT of stator current in faulty induction motor is measured and compared with various reference fault data in data base to diagnose the fault. This paper is focused on to predict and diagnose of the health state of induction motors in steady state. Also, it can be given to motor operator and maintenance team in order to enhance an availability and maintainability of induction motors. Experimental results are demonstrated that the proposed system is very useful to diagnose the fault and to implement the predictive maintenance of induction motors.
A Study on Accuracy Improvement in Measuring Liquid Level inside Pressurized Vessels
Kim, Ho-Yol ; Byun, Seung-Hyun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1889~1893
Differential pressure type level measuring systems have been using widely for industrial applications like drum level measurements in power plants. Because of difficulties in specific gravity compensation for vapor and liquid inside the vessel and the sensing lines, this type of measuring systems reveal significant measuring error. In this paper, the major reason causing errors on the differential pressure type level measurement is analyzed and a method of more accurate calculation for specific gravity compensation is introduced.
A Robust Sliding Mode Controller for Unmatched Uncertain Severe Sate Time-Delay Systems
Lee, Jung-Hoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1894~1899
This note is concerned with a robust sliding mode control(SMC) for a class of unmatched uncertain system with severe commensurate state time delay. The suggested method is extended to the control of severe state time delay systems with unmatched uncertainties except the matched input matrix uncertainty. A transformed sliding surface is proposed and a stabilizing control input is suggested. The closed loop stability together with the existence condition of the sliding mode on the proposed sliding surface is investigated through one Lemma and two Theorems by using the Lyapunov direct method with the concept of the control Lyapunov function instead of complex Lyapunov-Kravoskii functionals. Through an illustrative example and simulation study, the usefulness of the main results is verified.
Performance Improvement of the Active Noise Control System Using RCMAC and PSO Method
Han, Seong-Ik ; Shin, Jong-Min ; Kim, Sae-Han ; Lee, Kwon-Soon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1900~1907
In this paper, a recurrent cerebellar modulation articulation control with praticle swarm optimization (PSO) method has been investigated for improvement of noise attenuation performance in active noise control system. For narrow band noise, FXLMS and RCMAC has a partial satisfactory noise attenuation. However, noise attenuation performance is poor for broad band noise and nonlinear path since it has linear filter structure. To improve this problem, a RCMAC with PSO is proposed and it is shown that satisfactory noise attenuation performance is obtained by some simulations in duct system using harmonic motor noise and KTX cabin noise as a noise source.
A Robust Variable Structure Controller for the Mixed Tracking Control of Robot Manipulators
Lee, Jung-Hoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1908~1913
In this paper, a robust variable structure tracking controller is designed for the mixed tracking control of highly nonlinear rigid robot manipulators for the first time. The mixed control problem under consideration is extended from the basic tracking problem, with the different initial condition of both the planned trajectory and link of robots. This control problem in robotics is not addressed to until now. The tracking accuracy to the sliding trajectory after reaching is analyzed. The stability of the closed loop system is investigated in detail in Theorem 2. The results of Theorem 2 provide the stable condition for control gains. Combing the results of Theorem 1 and Theorem 2 gives rise to possibility of designing the improved variable structure tracking controller to guarantee the tracking error from the determined sliding trajectory within the prescribed accuracy after reaching. The usefulness of the algorithm has been demonstrated through simulation studies on the mixed tracking control of a two.link robot under parameter uncertainties and payload variations.
Channel Prediction based MAC Protocol in Cognitive Radio Networks.
Zhu, Wen-Min ; Park, Hyung-Kun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1914~1916
Cognitive radio MAC protocol should allow secondary users to access unused or under-utilized spectrum without interference to primary users. For cognitive MAC protocol, one of the important issues is how to select the channel opportunities for secondary users. In this paper, we propose a novel cognitive MAC protocol to allocate channel opportunities for the secondary users based on the prediction of future availability. The proposed MAC protocol can reduce the interference to primary users and increase throughput using multiple channels.
A Design of Behavioral Simulation Platform for Near Field Communication Transceiver using MATLAB Simulink
Ahn, Deok-Ki ; Bae, Sang-Geun ; Hwang, In-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1917~1922
Near-Field Communication (NFC) is a short-range wireless communication technology evolved from RFID especially for the exchange of data between active and passive devices. This paper presents the mathematical models for the signal path of a NFC transceiver system and a behavioral simulation platform using MATLAB simulink. The approximated mathematical models simplify the simulation complexity of a transceiver and provide a quick evaluation. With this calculation platform, we can evaluate the system performance caused by the noise and the non-linearity of the individual blocks, and caused by system variables such as Effective Number of Bits (ENOB) of ADC and filter cutoff frequency. This platform provides us with a rapid prototyping, a reliable system design, and an efficient risk management during development of the NFC transceiver ICs.
Preemptive Ethernet Controller to Improve Real-Time Characteristics of IEC 61850 Protocol
Lee, Bum-Yong ; Park, Tae-Rim ; Park, Jae-Hyun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 59, issue 10, 2010, Pages 1923~1928
The IEC 61850 protocol proposed for the interoperability between IEDs(intelligent electronic devices) adopts the prioritized switched ethernet as its communication channel because substation bus is utilized to exchange both real-time and non real-time messages. The prioritized switched ethernet uses IEEE 802.1Q/p QoS(Quality of Service) in addition to IEEE 802.3 ethernet to enhance the real-time characteristics. However, IEEE 802.1Q/p QoS has priority-blocking problem that occurs when higher-priority frame transmission request during lower-priority frame transmission. To resolve this problem, this paper proposes P(Preemptive)-Ethernet. P-Ethernet uses the modified IEEE 802.1Q/p frame format and new priority preemption mechanism. This paper also implements P-Ethernet controller using FPGA (Virtex-4) and MicroBlaze processor. From the implementation results, P-Ethernet controller shows a improved latency and jitter of transmission period compare to the normal ethernet controller.