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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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The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 61, Issue 12 - Dec 2012
Volume 61, Issue 11 - Nov 2012
Volume 61, Issue 10 - Oct 2012
Volume 61, Issue 9 - Sep 2012
Volume 61, Issue 8 - Aug 2012
Volume 61, Issue 7 - Jul 2012
Volume 61, Issue 6 - Jun 2012
Volume 61, Issue 5 - May 2012
Volume 61, Issue 4 - Apr 2012
Volume 61, Issue 3 - Mar 2012
Volume 61, Issue 2 - Feb 2012
Volume 61, Issue 1 - Jan 2012
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Leader-Follower Model Analysis on Mixed Strategy Nash Equilibrium of Electricity Market with Transmission Congestion
Lee, Kwang-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 187~193
DOI : 10.5370/KIEE.2012.61.2.187
Nash Equilibrium (NE) is as useful tool for investigating a participant`s strategic generation quantity in a competitive electricity market. Cournot model may give a mixed strategy NE instead of a pure strategy when transmission constraints are considered. A mixed strategy is difficult to compute, complicated to understand conceptually, and hard to implement in an electricity market practically. This paper presents that a mixed strategy does not appear in Stackelberg leader-follower model even under a transmission congestion. A solution method is proposed for the leader-follower model under a nondifferentiable space of a strategy variable. Based on the pure strategy NE with a transmission line congested, the merit of leader-follower model is shown from a social welfare point of view.
The Study on Application of Flying Inspection Method for the 22.9kV Distribution Line
Zhang, Jeong-Il ; Kang, Byoung-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 194~198
DOI : 10.5370/KIEE.2012.61.2.194
This paper describes flying inspection apparatus for 22.9kV distribution line. This apparatus is composed of multi-copter(more than 4 propellers), camcorder and remote controller. The existing inspections, such as hot-line inspection job and optical inspection method and distribution Line Checking Robot, have many restrictions. A electric working vehicle and hot-line job license are essential in hot-line inspection job. Besides its high cost, it can`t be applied to the electric pole over 18m and road-blocked area. Optical method can`t inspect upper side of electric facilities mounted on the electric pole. Robot method can`t be applied to the corroded overhead earth wire and nothing of overhead earth wire. To solve the problems, in Korea Electric Power Co., we have applied flying inspection apparatus to the 22.9kV distribution line. The results of trial application show that this paper is practical and effective for the inspection technical method in 22.9kV distribution line
Dynamic Voltage Restorer (DVR) for 6.6[kV]/60[Hz] Power Distribution System Using Two Quasi Z-Source AC-AC Converters
Oum, Jun-Hyun ; Jung, Young-Gook ; Lim, Young-Cheol ; Choi, Joon-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 199~208
DOI : 10.5370/KIEE.2012.61.2.199
This paper proposes a quasi Z-source DVR(Dynamic Voltage Restorer) system with a series connection of the output terminals, to compensate the voltage variations in the 6.6[kV]/60[Hz] power distribution system. The conventional DVR using one quasi Z-source AC-AC converter has the advantage which it can compensate the voltage variations without the need for the additional energy storage device such as a battery, but it is impossible to compensate for the 50[%] under voltage sags. To solve this problem, a DVR system using two quasi Z-source AC-AC converters with the series connection of the output terminals is proposed. By controlling the duty ratio D in the buck-boost mode, the proposed system can control the compensation voltage. For case verification of the proposed system, PSIM simulation is achieved. As a result, in case that the voltage sags-swells occur 10[%], 20[%], 60[%] in power distribution system, and, in case that the 50[%] under voltage sags-swells continuously occur, all case could compensate by the proposed system. Especially, the compensated voltage THD was examined under the condition of the 10[%]~50[%] voltage sags and the 20[
] load changes. The compensated voltage THD was worse for the higher load resistances and more severe voltage sags. Finally, In case of the voltage swells compensation, the compensation factor has approached nearly 1 regardless of the load resistance changes, while the compensation factor of voltage sags was related to the load variations.
The Inductance Computation of IPMSM using Direct-current Diminution Test
Cho, Gyu-Won ; Jo, Jae-Ok ; Woo, Seok-Hyeon ; Jang, Ki-Bong ; Kim, Gyu-Tak ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 209~215
DOI : 10.5370/KIEE.2012.61.2.209
This paper deals with a reduction of cogging torque and estimate of inductance for IPMSM. The flux barriers(Barrier) and the auxiliary slot(Notch) for the reduction of cogging torque was installed for increase of driving characteristic in IPMSM. The cogging torque, driving torque and inductance are analyzed by using FEM(Finite Element Method) and the results of inductance calculation are compared to experimentation ones.
Optimal Design of Interior PM Synchronous Machines Using Randomly-Guided Mesh Adaptive Direct Search Algorithms
Kim, Kwang-Duck ; Lee, Dong-Su ; Jung, Sang-Yong ; Kim, Jong-Wook ; Lee, Cheol-Gyun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 216~222
DOI : 10.5370/KIEE.2012.61.2.216
Newly proposed RG-MADS (Randomly Guided Mesh Adaptive Direct Search) has been applied to the optimal design of Interior Permanent Magnet Synchronous Motor (IPMSM) which has the distinctive features of magnetic saturation. RG-MADS, advanced from classical MADS algorithm, has the superiority in computational time and reliable convergence accuracy to the optimal solution, thus it is appropriate to the optimal design of IPMSM coupled with time-consuming Finite Element Analysis (FEA), necessary to the nonlinear magnetic application for better accuracy. Effectiveness of RG-MADS has been verified through the well-known benchmark-functions beforehand. In addition, the proposed RG-MADS has been applied to the optimal design of IPMSM aiming at maximizing the Maximum Torque Per Ampere (MTPA), which is regarded as representative design goal of IPMSM.
A Study of a Manual Generator System for 50Wh Battery Charge
Lee, Ji-Young ; Koo, Dae-Hyun ; Han, Choong-Kyu ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 223~230
DOI : 10.5370/KIEE.2012.61.2.223
This paper deals with an design of axial flux electric machine which is a key element for a compact size in a portable and manual generator system. It is expected that the generator system with an axial flux electric machine is more light and has higher efficiency than other types of generator systems. And it is used the soft magnetic composite core instead of silicon steel core in the axial flux electric machine for more compact size. The weight and efficiency of the generator system are the main keys to select the value of design variables. In this paper, the overall design process to meet the design goals, and the design results are presented with experiment results.
The MPPT Control Method of the PMSG Wind Generation System using the Turbine Model with a Squirrel Cage Induction Motor
Lee, Joon-Min ; Kim, Dong-Hwa ; Shin, Hye-Su ; Kim, Young-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 231~236
DOI : 10.5370/KIEE.2012.61.2.231
This paper presents the MPPT(Maximum Power Point Tracking)control method of the PMSG wind generation system using the turbine model with a squirrel cage induction motor. The torque of squirrel cage induction turbine model is controlled by mathematization of speed characteristics of real blade. In this paper, maintenance and cost issues into consideration, except for previous method using information of the velocity of the wind speed sensor, the algorithm is presented. The algorithm is controlled by tracking the optimal point, the generator speed and maximum grid power. The vector controls of the generator side converter and the grid side converter are controlled respectively to obtain maximum torque and regulate unity power factor. With Psim simulations and experiments, the efficiency of squirrel cage induction turbine model and the validity of control algorithm are verified.
Effects of Dielectric Layer Thickness and Electrode Structures on High Xe AC-PDP
Heo, Jun ; Kim, Yun-Gi ; Kim, Dong-Hyun ; Lee, Hea-June ; Lee, Ho-Jun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 237~242
DOI : 10.5370/KIEE.2012.61.2.237
In this paper, we investigated effects of ITO electrode geometry and dielectric layer thickness on the discharge Characteristic of AC PDP. As the dielectric thickness is decreased (
), firing and sustain voltage is decreased. Luminance and discharge power increase with decreasing dielectric layer thickness because of increasing capacitance between plasma and electrodes. Reactive power decreases with dielectric thickness due to reduced capacitance between sustain electrodes. For the high Xe test panel with small ITO electrode, luminous efficacy as well as luminance increase with decreasing dielectric layer thickness. This result suggest that high power density and small plasma volume is beneficial for high efficacy discharge.
A Study on MgCaO Protective Layer and Single Crystal MgO Powder Coating to Improve the Characteristic of AC-PDP
Park, Se-Hun ; Wi, Sung-Suk ; Kim, Dong-Hyun ; Lee, Hae-June ; Lee, Ho-Jun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 243~250
DOI : 10.5370/KIEE.2012.61.2.243
In this study, we attempted to reduce firing voltage of AC-PDP by alloying MgO protective Layer with CaO. Also, spray coating of single crystal MgO powder has been used to improving Exo-electron emission characteristics and reducing the statistical discharge delay in plasma displays. The properties of discharge depending upon the single crystal MgO powder are investigated. Plasma display having powder coated MgCaO Protective Layer shows lower driving voltage and higher efficacy than of uncoated, conventional panel.
A Study on the Partial Discharge Location Method using 2 Sensors
Kim, Jeong-Tae ; Kim, Dong-Wook ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 251~256
DOI : 10.5370/KIEE.2012.61.2.251
This study deals with the location of partial discharges(PDs) for power cables and GIS using 2 PD sensors and long coaxial signal cables. Throughout the experiments by use of simulated PD pulses and corona discharges in the power cable system, it is found out that the impedance matching between the coaxial signal cable and the measuring equipment should be done for good S/N ratio and the on-site measurement using more than 100m-long coaxial signal cable is possible. In addition, new PD location algorithm with the polarities of PD pulses and the arrival time difference between two pulses was proposed and was proved through the partial discharge experiments for the cable joint defect and artificial void defect.
Design of LNA and Mixer for Ku-band Receiver
Choi, Hyuk-Jae ; Ko, Jae-Hyeong ; Kim, Koon-Tae ; Lee, Je-Kwang ; Kim, Hyeong-Seok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 257~262
DOI : 10.5370/KIEE.2012.61.2.257
The Ministry of Information-Communication assigned 18~19GHz frequency band for communication of cabins and platform to link between subway/train and it`s station. In this paper, we propose wireless transmission devices which are 2 stage hybrid low noise amplifier of 18GHz band and mixer for 18GHz as well to apply for RF receiver. We designed LNA to be noise matched its 1st stage and gain matched for 2nd stage and mixer using
hybrid coupler to suppress the spurious signal. The transistors of 18 GHz LNA and mixer are NE3210S01 of NEC and KMB-N51-1, respectively. As the result of simulation, we get 19.92dB gain and 2.06dB noise figure with LNA and 8.61dB conversion loss with mixer.
High-Frequency Analysis Modeling of Hybrid Vehicle Battery
Lee, Jae-Joong ; Lee, June-Sang ; Kim, Mi-Ro ; Kweon, Hyck-Su ; Nah, Wan-Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 263~269
DOI : 10.5370/KIEE.2012.61.2.263
In order to present that the electromagnetic compatibility standards following the frequency goes up which is based automotive electronics, in this paper, a hybrid/electric vehicle battery which reflects the frequency of the equivalent circuit model is introduced. By using this circuit modeling, the impedance characteristics can be analysed and an analyze of battery one cell is finished. Using this model, each different from the discharging situation, the discharge characteristic curve could be led. Basic theoretical approaches and measuring results through MATLAB and experimental validation of the EIS measurement equipment was used.
A Compact Optical System using LED and CMOS Image Sensor for Liver Function Analysis
Kim, Chul ; Lim, Chang-Jin ; Nam, Myung-Hyun ; Kim, Dong-Sik ; Seo, Sung-Kyu ; Pak, Jung-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 270~275
DOI : 10.5370/KIEE.2012.61.2.270
This paper presents a portable and compact optical device which can conveniently be used to perform a functional analysis of human liver function. The proposed system employed red/green LEDs, as a light source, and CMOS image sensor, which is commonly used in cellular phones. With this system, several blood serum samples have been evaluated for liver functional analysis by measuring light absorption level through the blood serum samples depending on aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin concentration. The light absorption through the blood serum samples containing AST, ALT, or total bilirubin can provide their concentrations. The green light absorption is more sensitive to the concentration of AST or ALT, and the red light absorption is more sensitive to the total bilirubuin concentration. Additional calibration steps were performed by using a MATLAB program in order to eliminate the light scattering effects from the extraneous particles existing in each blood serum sample. From the blind test, three standard light intensity curves through each enzyme have been obtained and the enzyme concentration values have been compared to those obtained from a commercially available biochemistry analyzer (Toshiba 200 FR). The average percent difference in the obtained concentrations from two systems for AST, ALT, and total bilirubin concentration came out to be 7.79%, 7.98%. and 7.56%, respectively, with the adjusted coefficient of determination (R2) higher than 0.98. This system can possibly lead to a low-cost and simple system that can be used as a point-of-care (POC) system in a condition without advanced equipments.
Quasi-Optimal DOA Estimation Scheme for Gimbaled Ultrasonic Moving Source Tracker
Han, Seul-Ki ; Lee, Hye-Kyung ; Ra, Won-Sang ; Park, Jin-Bae ; Lim, Jae-Il ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 276~283
DOI : 10.5370/KIEE.2012.61.2.276
In this paper, a practical quasi-optimal DOA(direction of arrival) estimator is proposed in order to develop a one-axis gimbaled ultrasonic source tracker for mobile robot applications. With help of the gimbal structure, the ultrasonic moving source tracking problem can be simply reduced to the DOA estimation. The DOA estimation is known as one of the representative long-pending nonlinear filtering problems, but the conventional nonlinear filters might be restrictive in many actual situations because it cannot guarantee the reliable performance due to the use of nonlinear signal model. This motivates us to reformulate the DOA estimation problem in the linear robust state estimation setting. Based on the assumption that the received ultrasonic signals are noisy sinusoids satisfying linear prediction property, a linear uncertain measurement model is newly derived. To avoid the DOA estimation performance degradation caused by the stochastic parameter uncertainty contained in the linear measurement model, the recently developed NCRKF (non-conservative robust Kalman filter) scheme  is utilized. The proposed linear DOA estimator provides excellent DOA estimation performance and it is suitable for real-time implementation for its linear recursive filter structure. The effectiveness of the suggested DOA estimation scheme is demonstrated through simulations and experiments.
Linear Robust Target Tracking Filter Using the Range Differences Measured By Formation Flying Multiple UAVs
Lee, Hye-Kyung ; Han, Seul-Ki ; Ra, Won-Sang ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 284~290
DOI : 10.5370/KIEE.2012.61.2.284
This paper addresses a new passive target tracking problem using the range differences measured by cooperative UAVs. In order to solve the range difference based passive target tracking problem within the framework of linear robust state estimation, the uncertain linear measurement model which contains the stochastic parameter uncertainty is derived by using the noisy range difference measurements. To cope with the performance degradation due to the stochastic parameter uncertainty, the recently developed non-conservative robust Kalman filtering technique  is applied. For the cruciform formation flying UAVs, the relationship between the target tracking performance and the measurement errors is quantitatively analyzed. The proposed filter has practical advantages over the classical nonlinear filters because, for its recursive linear structure, it can provide satisfactory convergence properties and is suitable for real-time multiple UAVs applications. Through the simulations, the usefulness of the proposed method is demonstrated.
Dynamic Path Planning for Mobile Robots Using Fuzzy Potential Field Method
Woo, Kyoung-Sik ; Park, Jong-Hun ; Huh, Uk-Youl ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 291~297
DOI : 10.5370/KIEE.2012.61.2.291
In this paper, potential field algorithm was used for path planning in dynamic environment. This algorithm is used to plan a robot path because of its elegant mathematical analysis and simplicity. However, there are some problems. The problems are problem of collision risk, problem of avoidance path, problem of time consumption. In order to solve these problems, we fused potential field with fuzzy system. The input of the fuzzy system is set using relative velocity and location of robot and obstacle. The output of the fuzzy system is set using the weighting factor of repulsive potential function. The potential field algorithm is improved by using fuzzy potential field algorithm and, path planning in various environment has been done.
DSP Implementation of a Sinusoidal Encoder using linear Hall Sensor
Hwang, Jung-Ho ; Chung, Chan-Soo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 298~302
DOI : 10.5370/KIEE.2012.61.2.298
The linear encoder used in the BLAC driving circuit consists usually analog type sensor, and need signal transform from analog sinusoidal to digital one for application in the PWM algorithm that is used to control motor current. When the motor is driven in low speed, it is required many operations and higher quality DSP to convert the hole sensor signal to digital one with enough resolution. In this paper, the another method to convert that signal with enough resolution without calculation of sine function is proposed. This is very simple and have high resolution even if the motor is driving in low speed. To verify the proposed method, BLAC motor is used, and it is proved that the motor is tracking well the reference step signal in the low speed as well as in the high one.
Analysis of Dynamic Model and Design of Optimized Fuzzy PID Controller for Constant Pressure Control
Oh, Sung-Kwun ; Cho, Se-Hee ; Lee, Seung-Joo ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 303~311
DOI : 10.5370/KIEE.2012.61.2.303
In this study, we introduce a dynamic process model as well as the design methodology of optimized fuzzy controller for its efficient application to vacuum production system to produce a semiconductor, solar module and display and so on. In a vacuum control field, PID control method is widely used from the viewpoint of simple structure and preferred performance. But, PID control method is very sensitive to the change of environment of control system as well as the change of control parameters. Therefore, it`s difficult to get a preferred performance results from target system which has a complicated structure and lots of nonlinear factors. To solve such problem, we propose the design methodology of an optimized fuzzy PID controller through a following series of steps. First a dynamic characteristic of the target system is analyzed through a series of experiments. Second the process model is built up and its characteristic is compared with real process. Third, the optimized fuzzy PID controller is designed using genetic algorithms. Finally, the fuzzy controller is applied to target system and then its performance is compared with that of other conventional controllers(PID, PI, and Fuzzy PI controller). The performance of the proposed fuzzy controller is evaluated in terms of auto-tuned control parameters and output responses considered by ITAE index, overshoot, rise time and steady state time.
A new Design of Granular-oriented Self-organizing Polynomial Neural Networks
Oh, Sung-Kwun ; Park, Ho-Sung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 312~320
DOI : 10.5370/KIEE.2012.61.2.312
In this study, we introduce a new design methodology of a granular-oriented self-organizing polynomial neural networks (GoSOPNNs) that is based on multi-layer perceptron with Context-based Polynomial Neurons (CPNs) or Polynomial Neurons (PNs). In contrast to the typical architectures encountered in polynomial neural networks (PNN), our main objective is to develop a methodological design strategy of GoSOPNNs as follows : (a) The 1st layer of the proposed network consists of Context-based Polynomial Neuron (CPN). In here, CPN is fully reflective of the structure encountered in numeric data which are granulated with the aid of Context-based Fuzzy C-Means (C-FCM) clustering method. The context-based clustering supporting the design of information granules is completed in the space of the input data while the build of the clusters is guided by a collection of some predefined fuzzy sets (so-called contexts) defined in the output space. (b) The proposed design procedure being applied at each layer of GoSOPNN leads to the selection of preferred nodes of the network (CPNs or PNs) whose local characteristics (such as the number of contexts, the number of clusters, a collection of the specific subset of input variables, and the order of the polynomial) can be easily adjusted. These options contribute to the flexibility as well as simplicity and compactness of the resulting architecture of the network. For the evaluation of performance of the proposed GoSOPNN network, we describe a detailed characteristic of the proposed model using a well-known learning machine data(Automobile Miles Per Gallon Data, Boston Housing Data, Medical Image System Data).
Sensing Period Adaptation using the Cost Function in the Cognitive Radio Networks
Gao, Xiang ; Park, Hyung-Kun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 321~323
DOI : 10.5370/KIEE.2012.61.2.321
Cognitive radio has been recently proposed to dynamically access unused-spectrum. Since the spectrum availability for opportunistic access is determined by spectrum sensing, sensing is identified as one of the most crucial issues of cognitive radio networks. The PHY-layer sensing, as a part of spectrum sensing in cognitive radio, concerns the sensing mechanism to determine channel to be sensed and to access. One of the important issues in the PHY-layer sensing control is to find an available sensing period and trade-off between spectrum sensing and data transmission. In this paper, we show the relationship between spectrum sensing and data transmission according to the sensing period. We analyze and propose the new scheme to evaluate optimal sensing period.
Design of Wide - range Clock and Data Recovery Circuit based Dual-loop DLL using 2-step DPC
Jung, Ki-Sang ; Kim, Kang-Jik ; Ko, Gui-Han ; Cho, Seong-Ik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 324~328
DOI : 10.5370/KIEE.2012.61.2.324
A recovered jitter of CDR(Clock and Data Recovery) Circuit based on Dual-loop DLL(Delay Locked Loop) for data recovery in high speed serial data communication is changed by depending on the input data and reference clock frequency. In this paper, 2-step DPC which has constant jitter performance for wide-range input frequency is proposed. The designed prototype 2-step CDR using proposed 2-step DPC has operation frequency between 200Mbps and 4Gbps. Average delay step of 2-step DPC is 10ps. Designed CDR circuit was tested with 0.18um CMOS process.
A Study on the Method to Minimize Measuring Burial Depth Error for Submarine Cable
An, Yong-Ho ; Kim, Yong-Hak ; Han, Jeong-Yeol ; Lee, You-Jin ; Han, Byoung-Sung ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 329~334
DOI : 10.5370/KIEE.2012.61.2.329
The distribution submarine cables are normally used for power supply at island, which are mostly installed in the southern coast of KOREA, and partially installed in the west coast and Jeju-Island. There are two way of submarine cable burying system, buried and unburied type. Since 2003, KEPCO is entirely being constructing the distribution submarine cable by buried type. In this case, `burial depth` is key index for evaluating the suitability of the buried situation. Therefore, the measurement accuracy of `burial depth` is a big issue for burying system in the distribution submarine cable. This paper demonstrates the measurement error of burial depth that is affected by electrical factor such as grounding type of submarine cable in case of magnetic field detection method, and indicates the method to reduce the measurement error in buried type of distribution submarine cable system.
A Study on the Manufacture of Single Axis Tracking Solar Power Generation System for BIPV
Cho, Jae-Cheol ; Lee, Jin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 335~338
DOI : 10.5370/KIEE.2012.61.2.335
Recently, the energy has been used much more than ever, but there has been many problems including atmospheric pollution. So we need alternative energy resources, which are solar heat, solar light, wind power, small water power, etc. The field, which is most popular these days, is the energy source by solar light which transform electric energy using the solar cell and it is available with many researches. In this paper, we manufactured the solar power generation system over 90W using solar module which was 9.90V for Voc, 0.93 A for Isc, 8.64 V for Vmp, 0.75 A for Imp, 6.5 W for power. System was controlled by step motor with worm gear to operate optimum condition between
angle. This system was very effective in tracking space use because it need less space than general solar module.
A Study on the Magnetic Properties of Ceramics Superconductors for Simpllified Testing System
Lee, Sang-Heon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 339~341
DOI : 10.5370/KIEE.2012.61.2.339
The high Tc superconductor of YBCO system with the nominal composition of precursor was prepared from mixed powders of
, CuO and
by the thermal pyrolysis method. The effect of
doping to Y based ceramics superconductors fabricated by the thermal pyrolysis reaction, to investigate the effect of the dopant on the superconductivity. The voltage appearing across the field-cooled HTS sample increased with external magnetic field. The improvement of critical current property as well as the mechanical property is important for the application. The improvement of the critical current can be achieved by forming the nano size defect working as a flux pining center inside the superconductor. We simply added
to starting materials to dope
and observed an increase in the trapped field and the critical current density up to at least 5 wt %
was converted to fine
particles which were trapped in YBCO matrix during the sintering process. We observed a peak effect of Jc that can be attributed to
doping and results suggest that introducing a proper amount of pinning centers can significantly enhance current density.
Correlation Analysis about Loop Impedance and Load Condition
Jung, Jin-Soo ; Kim, Han-Sang ; Kim, Sun-Gu ; Han, Woon-Ki ; Park, Chan-Eom ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 342~346
DOI : 10.5370/KIEE.2012.61.2.342
This paper presents a loop impedance(inner loop impedance & external impedance) measurement method in TN system. When the measurement of a loop impedance then the measurement result have a some error by load condition. In this paper suggest the loop impedance measurement on actual loading condition by two experiment. one was laboratory condition and the other was the actual measurement on site. Analysis result, measuring error by load condition has not effect on measuring loop impedance.
A Study on Design and Operation Performance of Automatic Fire Detection Equipment (P-type One-class Receiver) by Bidirectional Communication
Lee, Bong-Seob ; Kwak, Dong-Kurl ; Jung, Do-Young ; Cheon, Dong-Jin ;
The Transactions of The Korean Institute of Electrical Engineers, volume 61, issue 2, 2012, Pages 347~353
DOI : 10.5370/KIEE.2012.61.2.347
In this paper, authors will develop the quick and precise remote controller of automatic fire detection equipment (P-type one-class receiver) based on information communication technology (IT). The remote controller detects the fire and disaster in the building automatically and quickly and then activates the facilities to extinguish the fire and disaster, monitoring such situation in a real time through wire-wireless communication network. The proposed remote controller is applied a programmable logic device (PLD) micom. of one-chip type which is small size and lightweight and also has highly sensitive-precise reliabilities. The one-chip type PLD micom. analyzes digital signals from sensors, then activates fire extinguishing facilities for alarm and rapid suppression in a case of fire and disaster. The detected data is also transferred to a remote situation room through wire-wireless network of RS232c and bluetooth communication, and then the situation room sends an emergency alarm signal. The automatic fire detection equipment (AFDE) based on IT will minimize the life and wealth loss while prevents fire and disaster.