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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 P
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Journal DOI :
The Korean Institute of Electrical Engineers
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Volume & Issues
Volume 63, Issue 4 - Dec 2014
Volume 63, Issue 3 - Sep 2014
Volume 63, Issue 2 - Jun 2014
Volume 63, Issue 1 - Mar 2014
Selecting the target year
The Pitch/Turning Control Driver Design Modeling of Permanent Magnet Synchronous Motor
Lee, Chun-Gi ; Hwang, Jeong-Won ; Lee, Joung-Tae ; Yang, Bin ; Lim, Dong-Keun ; Park, Seung-Yub ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 219~225
DOI : 10.5370/KIEEP.2014.63.4.219
The purpose of this paper is to control of the low-speed, high-precision PMSM 2-axes pitch/turning. In this paper, apply the PAM-PWM inverter for it. However, The PAM-PWM inverter, control algorithms and hardware is complex. But it is possible to improve the performance in the low-speed operation can reduce the effect of the PWM ripple and Dead Time of inverter by applying suitable DC-bus voltage control. The direct driver PMSM(Permanent Magnet Synchronous Motor) configured to vector control part, PAM control part and the other controller. The vector control part includes PI current, speed control, additional space vector modulation. PAM control part has to have PI voltage controller and P current controller for DC-bus voltage control. Besides, the motor position estimator, the speed estimator and the counter electromotive force and Dead Time Compensation are added. With this arrangement, PMSM was driven with a low pole pitch/turning by performing the current control to the current command or torque command is the paper. As a result, it was possible to minimize the disturbance component that appears in the drive in proportion to the DC voltage magnitude. The use of a hydraulic drive method for a two-axis bubble column is a typical tank. When using the PWM PAM inverter driver is in the turret can be driven by high-precision, low vibration, low noise compared to the hydraulic drive may contribute to the computerization of the turret.
Railway System Functional Safety and Certification
Kim, You-Ho ; Lee, Soo-Hwan ; Park, Kang-Hun ; Ko, Tae-Kuk ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 226~235
DOI : 10.5370/KIEEP.2014.63.4.226
Nowadays, railroads are considered the most efficient form of mass transportation. Furthermore, it is necessary that railroads be paired with state-of-the-art safety equipment. Unfortunately, it is impossible to prevent 100% of accidents that may be caused by system or human errors. In order to prevent future accidents, RAMS activity and Functional Safety Certification are required for new systems that are under development. In this paper we evaluate the necessity of the application of RAMS and the performance of RAMS in the system development process. We also explore the Safety Evaluation Procedure required for RAMS certification.
A Research on Self-excitation and Power Factor Compensation of Induction Motor
Kim, Jong-Gyeum ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 236~240
DOI : 10.5370/KIEEP.2014.63.4.236
Induction motor requires a rotating magnetic for rotation. Current required to generate the rotating magnetic field is magnetizing current. This magnetizing current is associated with the reactive power. This reactive power must be supplied from source side. Therefore, the power factor of the induction motor is low. So, the capacitor is installed on the motor terminals to compensate for the low power factor. Power supply company has recommended to maintain a high power factor to the customer. If the capacitor current is greater than the magnetizing current of the motor, there is a possibility that the self-excitation occurs. So it is necessary to calculate the optimal capacity capacitor current does not exceed the magnetizing current. In this study, we first compute the no-load current and the reactive power of the induction motor and then calculates the limit of the maximum power factor without causing self-excitation.
Parameters Estimation of Five-Phase Squirrel-Cage Induction Motor in Changing Variable Frequency
Kim, Min-Huei ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 241~247
DOI : 10.5370/KIEEP.2014.63.4.241
This paper propose a variable parameter estimations of five-phase squirrel-cage induction motor(IM) for speed control system. In order to high performance control of AC motor using a field oriented control(FOC) and direct torque control(DTC) algorithm, there are required precise motor parameters for slip calculation, flux observer, controller gain, rotor position, speed estimation, and so on. We are suggest a analyzed estimation results of the motor parameters that developing five-phase squirrel-cage IM have a stator of concentrated winding for experimental of variable input power frequency. There are results of stator winding test, no-load test, locked-rotor test, variable actual load test, and estimated parameters of equivalent circuits using manufactured experimental apparatus by IEEE Standard Test Procedure for Polyphase Induction Motors and Generators 112-2004.
Control of a Bridgeless PFC with the Discontinuous Conduction Mode
La, Jae-Du ; Lee, Yong-Geun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 248~253
DOI : 10.5370/KIEEP.2014.63.4.248
Generally, power factor correction (PFC) techniques play an important role in the power supply technology. Many new circuit topologies and control strategies for PFC have been proposed. Among them, the brideless PFC (BPFC) reduces the number of switching devices and the losses and improves the power density as well. Moreover, by implementing the improved topology in the discontinous conduction mode (DCM) it ensures almost unity power factor in a simple and effective manner. In the DCM operation gives additional advantages such as zero-current turn-on in the power switches, zero-current turn-off in the output diode and reduces the complexity of the control circuitry. In this paper, a new control strategy for the BPFC is proposed. Also, the performance of the proposed system is demonstrated through experiments.
Assessment of performance for Output Power Control of Wind Turbine using Energy Storage System
Hong, Jong-Seok ; Choi, Chang-Ho ; Lee, Joo-Yeon ; Kim, Jae-Chul ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 254~259
DOI : 10.5370/KIEEP.2014.63.4.254
In this paper, we describe construction of a wind stabilization demo-site and effects of output power control of wind turbines for suppression of ramp rate using ESS (Energy Storage System). It is difficult to control the output power of distributed generator such as wind turbine which of variation is very large. If the large capacity wind farm be interconnected into power system may cause blackout due to Power Quality. For these reasons, the international standards such as Grid-Code is limited to less than 10 [%/min] of renewable energy ramp rate. The case of Korea, government actively conducts propagating large-scale renewable energy for green growth policy, to interconnecting more renewable energy into power system is necessary for stabilization technology. For these reasons, the POSCO consortium has constructed a wind stabilization demo-site that is configured as 500 [kWh] battery energy storage systems can output up to 3 [C-Rate] and two wind turbines rated 750 [kW]. In POSCO consortium, which implements various methods stabilizing output power of wind turbine such as smoothing, section firming and ramp control, we derive the results of long-term demonstration that can be controlled to satisfy to the international standard about ramp rate [%/kW] of wind turbine output power.
Performance of CLMS Algorithm for Real-time Application in ANC Systems of Road Noise Input
Moon, Hak-Ryong ; Shon, Jin-Geun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 260~265
DOI : 10.5370/KIEEP.2014.63.4.260
Recently, many active noise control (ANC) systems, which employ the adaptive filter controlling method, have been reported for eliminating unwanted noise. ANC systems based on the filtered-X least mean square (FXLMS) algorithm have a problem with compensating the acoustic feedback of secondary route. It is difficult to apply the real time, because transfer function of secondary route must be measured by off-line method to solve this problem. In this paper, we propose the ANC system that applies a correlation LMS(CLMS) algorithm for improving a problem of transfer function measurement. The proposed algorithm is based on input of road noise. The proposed ANC systems have an advantage of real-time process without degradation of performance, although there are many calculation compared with FXLMS algorithm.
Reliability Cost Evaluation of Power Distribution System with Superconducting Fault Current Limiter
Moon, Jong-Fil ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 266~270
DOI : 10.5370/KIEEP.2014.63.4.266
In this paper, the effects of superconducting fault current limiter (SFCL) installed in power distribution system on reliability are evaluated and analyzed. The fault current will be decreased in power distribution system with SFCL because of the increased impedance of SFCL. The decreased fault current will improve the voltage drop of the bus of substation. The voltage drop is an important factor of power distribution system reliability. In this paper, improvement of reliability worth is analyzed when SFCLs are installed at the starting point in power distribution system. First, resistor-type SFCL model is used in PSCAD/EMTDC. Next, typical power distribution system is modeled. Finally, when the SFCLs with impedance 0.5 [
] are installed in feeder, power distribution system reliability is evaluated. Also, the improvement effect of reliability worth including the effect of voltage sag is analyzed using customer interruption cost according to whether or not SFCL is installed.
Characterization of LED Lighting according to Voltage Variation
Lee, Dae-Woo ; Lee, Jong-Pil ; Ji, Pyeong-Shik ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 271~276
DOI : 10.5370/KIEEP.2014.63.4.271
LED lighting has received worldwide attention as advantages, such as environment-friendly than the conventional light, the excellent energy efficiency, and a semi-permanent lifetime. The use of the SMPS increased with the rapid growth in the LED industry. Increased use of SMPS means an increase in the harmonic generation load. Therefore, LED lighting compared with conventional fluorescent lamps were tested in this paper for characterized by a light source, electrical and harmonic characteristics. Experiments results for LED lighting showed different characteristics from the existing fluorescent lamp. Especially harmonic characteristic results showed different characteristics in accordance with the power device manufacturing method for LED lighting.
Performance Test and Design of Harmonic Reduction Hybrid Transformer
Kim, Ji-Ho ; Han, Sung-Ho ; Son, Jin-Gun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 277~282
DOI : 10.5370/KIEEP.2014.63.4.277
Hybrid transformer means the distribution transformer, one of multi-function transformer equipped with the enhancement function of harmonics and unbalance. In other words, since existing transformer are equipped simply with transformation function only, a separated electric facility should be additionally installed in order to reduce the mutual harmonics and unbalance. Meanwhile, since hybrid transformer can perform the reduction of harmonics and unbalance as well as transformation function simultaneously through zigzag winding, it doesn`t need any additional electric facility. This study addressed the issue of developing and testing the performance of a generator that would reduce the harmonics supplied to the grid when grid-connected with the output of a photovoltaic inverter for photovoltaic generation system.
Heat & Cool Injection Molded Fresnel Lens Solar Concentrators
Jeong, Byeong-Ho ; Min, Wan-Ki ; Lee, Kang-Yeon ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 283~289
DOI : 10.5370/KIEEP.2014.63.4.283
A Fresnel lens is an optical component which can be used as a cost-effective, lightweight alternative to conventional continuous surface optics. Fresnel lens solar concentrators continue to fulfill a market requirement as a system component in high volume cost effective Concentrating Photovoltaic (CPV) electricity generation. The basic principles of the fresnel lens are reviewed and some practical examples are described. To investigate the performance space of the Fresnel lens, a fast simulation method which is a hybrid between raytracing and analytical computation is employed to generate a cache of simulation data. Injection molders are warming up to the idea of cycling their tool surface temperature during the molding cycle rather than keeping it constant. Heat and cool process are now also finding that raising the mold wall temperature above the resin`s glass-transition or crystalline melting temperature during the filling stage and product performance in applications from automotive to packaging to optics. This paper deals with the suitability of Fresnel lenses of imaging and non-imaging designs for solar energy concentration. The concentration fresnel lens confirmed machinability and optical transmittance and roughness measure through manufactured the prototype.
A Simulation Method of PID Tuning with Process Modeling in Operating Nuclear Power Plants
Min, Moon-Gi ; Jung, Chang-Gyu ; Lee, Kwang-Hyun ; Lee, Jae-Ki ; Kim, Hee-Je ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 290~294
DOI : 10.5370/KIEEP.2014.63.4.290
PID(Proportional, Integral, Derivative) controller is the most popular process controllers in nuclear power plants. The optimized parameter setting of the process controller contributes to the stable operation and the efficiency of the operating nuclear power plants. PID parameter setting is tuned when new process control systems are installed or current process control systems are changed. When the nuclear plant is shut down, a lot of PID tuning methods such as the Trial and Error method, Ultimate Oscillation method operation, Ziegler-Nichols method, frequency method are used to tune the PID values. But inadequate PID parameter setting can be the cause of the unstable process of the operating nuclear power plant. Therefore the results of PID parameter setting should be simulated, optimized and finally verified. This paper introduces the simulation method of PID tuning to optimize the PID parameter setting and confirms them of the actual PID controller in the operating nuclear power plants. The simulation method provides the accurate process modeling and optimized PID parameter setting of the multi-loop control process in particular.
A Study on Analysis of Propagation Speed of Power Frequency by Generation Drop
Kim, Hak-Man ; Park, Chul-Won ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 295~300
DOI : 10.5370/KIEEP.2014.63.4.295
The frequency is an important operating parameter of a power system. There is an increasing importance of constant monitoring of frequency to achieve stable power supply by WAMS(wide area monitoring system) and FNET(Frequency Monitoring Network). This paper is part of development of a network-based frequency monitoring and failure prediction system for wide-area intelligent protection relaying. In this paper, analysis of propagation speed of power frequency by generation drop using the PSS/E was carried out. For dynamic analysis, the 11 metropolitan areas offices of KEPCO divided into five groups of Seoul, Gangwon, Chungcheong, Honam, and Yeongnam group, study was performed.
A Study on the Electrical Breakdown Characteristics of Air according to Electrode Gap
Kang, Jong O ; Lee, Onyou ; Kim, Junil ; Bang, Seungmin ; Lee, Hongseok ; Lee, Jong Doug ; Kang, Hyoungku ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 301~306
DOI : 10.5370/KIEEP.2014.63.4.301
Recently in accordance with the rapid development of the industrial society, the accidents caused by dielectric breakdown have been increasing in power grid. It is important to prevent the dielectric breakdown of a high voltage apparatus to reduce the damage from electrical hazards. To establish an electrically reliable database of insulation design criteria for high voltage apparatus, a study on dielectric characteristics test is indispensable. In this study, dielectric characteristics according to field utilization factors (
) which are represented as the ratio of mean electric field to maximum electric field are investigated. the dielectric breakdown experiments by using several kinds of electrode systems made with stainless steel are performed by AC breakdown voltage under air-insulation. Also, the experimental results are analyzed by the Weibull distribution. As a result, it is found that the dielectric characteristics of air-insulation are determined by
as well as arrangement of electrode systems. It is considered that the results of this study would be applicable to designing the air-insulated high voltage apparatuses.
Development of Daily Peak Power Demand Forecasting Algorithm Considering of Characteristics of Day of Week
Ji, Pyeong-Shik ; Lim, Jae-Yoon ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 307~311
DOI : 10.5370/KIEEP.2014.63.4.307
Due to the increasing of power consumption, it is difficult to construct accurate prediction model for daily peak power demand. It is very important work to know power demand in next day for manager and control power system. In this research, we develop a daily peak power demand prediction method considering of characteristics of day of week. The proposed method is composed of liner model based on AR model and nonlinear model based on ELM to resolve the limitation of a single model. Using data sets between 2006 and 2010 in Korea, the proposed method has been intensively tested. As the prediction results, we confirm that the proposed method makes it possible to effective estimate daily peak power demand than conventional methods.
Analysis on Voltage Sag in Power Distribution System according to SFCL`s Impedance for Protective Coordination with Large Transformer
Kim, Jin-Seok ; Moon, Jong-Fil ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 312~316
DOI : 10.5370/KIEEP.2014.63.4.312
In this paper, a voltage sag is analyzed in case of superconducting fault current limiter (SFCL) installed in power distribution system where replaces the main power transformer to large one to meet the power demand. First, the power system is configurated to analyze the operation characteristics of the protective relay with replacement of the main transformer and application of the SFCL. Next, the method to meet the protection coordination is analyzed with large transformer using PSCAD/EMTDC. Finally, the bus voltage is investigated according to the impedance of both main transformer and SFCL in case that the SFCL is applied into feeder.
Ionization and Diffusion Coefficients in CH
Gas by Simulation
Kim, Sang-Nam ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 317~321
DOI : 10.5370/KIEEP.2014.63.4.317
This paper describes the information for quantitative simulation of weakly ionized plasma. We must grasp the meaning of the plasma state condition to utilize engineering application and to understand materials of plasma state. Using quantitative simulations of weakly ionized plasma, we can analyze gas characteristic. In this paper, the electron Ionization and diffusion Coefficients in
has been analysed over the E/N range 0.1~300[Td], at the 300[
] by the two term approximation Boltzmann equation method and Monte Carlo Simulation. Boltzmann equation method has also been used to predict swarm parameter using the same cross sections as input. The behavior of electron has been calculated to give swarm parameter for the electron energy distribution function has been analysed in
Application Analysis for Loss of Excitation Relay of Generator Protection
Oh, Yong-Taek ; Park, Chul-Won ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 322~326
DOI : 10.5370/KIEEP.2014.63.4.322
Recently, the LOE(loss of excitation) incidents are occurred in domestic synchronous generator frequently, the synchronous generator protection system has been much attention for the LOE protection of the incidents that threats synchronous generators and power systems. This paper was showed the characteristics and practices of distance relay that widely used LOE protection relaying in generator. Firstly, the operating characteristics and the impedance locus for LOE of the generator protection were introduced. Even if the conventional simulation program is used for modeling, but it is difficult to implement a LOE modeling and simulation of synchronous generator. So, the LOE relay operation data collected from thermal power plant and nuclear power plant in real fields were analyzed. By reviewing the applications of GE Mho relays, the reliability of LOE for synchronous generator protection in domestic were improved.
Temperature Characteristic Analysis according to Variation of Properties of Transformer Insulating Oil
Kim, Ji-Ho ; Rhee, Wook ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 327~332
DOI : 10.5370/KIEEP.2014.63.4.327
In this paper, the temperature distribution according to the property change of the insulating oil of the power transformer and max temperature were predicted through the ductility interpretation which heat-flow is coupled. By using CFD (Computation Fluid Dynamics) for the interpretation, the temperature distribution of 154kV the class single phase power transformer was predicted. The power loss causing the temperature rise of the transformer was changed to the heat source and we used as the input value for the heat-flow analysis. The temperature distribution was predicted according to the change of the density, specific heat, thermal conductivity and viscosity, that is the ingredient having an effect on the temperature rise of the transformer oil. The mineral oil of 4 kinds used in domestic and international based on the interpreted result was selected and the temperature distribution according to each load and Hot Spot temperature was predicted.
Analysis and Performance Test of Hybrid Transformer used in the Grid-Connected Photovoltaic Generation System
Kim, Ji-Ho ; Park, Hoon-Yang ; Shon, Jin-Geun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 333~338
DOI : 10.5370/KIEEP.2014.63.4.333
This paper concerns the development of the transformer that can reduce harmonics supplied to the system if the output of photovoltaic inverter in the photovoltaic system is grid-connected, and suggests that problems of harmonics and power factor degradation in the grid-connected photovoltaic system can be improved. In this study, the burden of increasing the investment in new facilities and securing their installation space due to harmonics has been substantially eased through the development of a hybrid transformer possessing unbalanced function and harmonics reduction function using zig-zag coils, and most of all, it is expected that the development of such high efficiency hybrid transformer possessing functions of transformation and reducing harmonics can improve the power quality as well as prevent damages caused by harmonics, leading to suppress unnecessary loss of electric power and thereby contribute to energy savings.
Economic Evaluation of Power Grid Interconnection between Offshore Wind Power Plants
Moon, Won-Sik ; Jo, Ara ; Kim, Jae-Chul ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 339~344
DOI : 10.5370/KIEEP.2014.63.4.339
An offshore wind power plant (WPP) is very expensive and different from an onshore wind power system in many ways. There has been a continuous increase in the capacity of the offshore WPPs. Therefore it is essential to analyze the feasibility and reliability of the offshore wind power to optimize their redundancy. Besides, it is very important to study a planning for grid interconnection of adjacent offshore WPPs. This paper proposes a economic evaluation method to interconnect with adjacent offshore substations in offshore wind power grid. Also, we suggest the probabilistic reliability method to calculate a probabilistic power output of the wind turbine and a cost of the expected energy not supplied that is used as the reliability index of the power system.
Failure Prediction Monitoring of DC Electrolytic Capacitors in Half-bridge Boost Converter
Seo, Jang-Soo ; Shon, Jin-Geun ; Jeon, Hee-Jong ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 345~350
DOI : 10.5370/KIEEP.2014.63.4.345
DC electrolytic capacitor is widely used in the power converter including PWM inverter, switching power supply and PFC Boost converter system because of its large capacitance, small size and low cost. In this paper, basic characteristics of DC electrolytic capacitor vs. frequency is presented and the real-time estimation scheme of ESR and capacitance based on the bandpass filtering is adopted to the single phase boost converter of uninterruptible power supply to diagnose its split dc-link capacitors. The feasibility of this real-time failure prediction monitoring system is verified by the computer simulation of the 5[kW] singe phase PFC half-bridge boost converter.
Growth Properties of Carbon nanowall according to the Reaction Gas Ratio
Kim, Sung-Yun ; Kang, Hyunil ; Choi, Won Seok ; Joung, Yeun-Ho ; Lim, Yonnsik ; Yoo, Youngsik ; Hwang, Hyun Suk ; Song, Woo-Chang ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 351~355
DOI : 10.5370/KIEEP.2014.63.4.351
Graphite electrodes are used for secondary batteries, fuel cells, and super capacitors. Research is underway to increased the reaction area of graphite electrodes used carbon nanotube (CNT) and porous carbon. CNT is limited to device utilization in order to used a metal catalyst by lack of surface area to improve. In contrast carbon nanowall (CNW) is chemically very stable. So this paper, microwave plasma enhanced chemical vapor deposition (PECVD) system was used to grow carbon nanowall (CNW) on Si substrate with methane (
) and hydrogen (
) gases. To find the growth properties of CNW according to the reaction gas ratio, we have changed the methane to hydrogen gas ratios (4:1, 2:1, 1:2, and 1:4). The vertical and surficial conditions of the grown CNW according to the gas ratios were characterized by a field emission scanning electron microscopy (FE-SEM) and Raman spectroscopy measurements showed structure variations.
Analysis on the Dielectric Characteristics of Gaseous Nitrogen for Developing Eco-friendly High Voltage Apparatuses
Bang, Seungmin ; Lee, Onyou ; Kim, Junil ; Kang, Jong O ; Lee, Hongseok ; Ko, Taekuk ; Kang, Hyoungku ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 356~360
DOI : 10.5370/KIEEP.2014.63.4.356
The environmental pollution caused by green-house gases such as
has been becoming the main issue of industrial society. As a part of these efforts, 180 countries signed the Kyoto Protocol in 1997 to cut back on their green-house gas emissions . Therefore, a study on the dielectric characteristics of the
is important for designing a eco-friendly high voltage apparatuses. In this paper, to develop an electrically reliable, stable, and eco-friendly high voltage apparatus, the breakdown voltage and partial discharge inception voltage characteristics in
considering utilization factors are studied for the establishment of insulation design criteria of an high voltage apparatus. Dielectric experiments are performed by using several kinds of sphere-plane electrode systems made of stainless steel. Also, the dielectric characteristics of the
are analyzed by using a Finite Elements Method (FEM) according to various field utilization factors. The results are expected to be applicable to designing the high voltage apparatuses using
as an insulation gas.
Development of Boost Chopper with Built New Renewable Energy in Grid-Connected Distributed Power System
Mun, Sang-Pil ; Lee, Su-Haeng ; Kim, Young-Mun ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 361~367
DOI : 10.5370/KIEEP.2014.63.4.361
This paper is related to a new solar power conditioner for a built-in step-up chopper function. In the first step-up chopper proposed solar PV power conditioner for mutually connected in series with the input voltage of the bypass diodes are respectively connected to the positive terminal should install the mutual boosting chopper diode connected in series with the boost chopper switching element between the two power supply and at the same time the first and the second was connected to a second diode and a resonance inductor and a snubber capacitor in series with each other. And the common connection point between the bypass diode and the step-up chopper and the step-up chopper diode common connection point of the switching elements of the input voltage was set to the boost inductor for storing energy. In addition, between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point of the first auxiliary diode and the second common connection point of the auxiliary diode was provided, the resonance capacitor. Between the step-up chopper and the step-up chopper diode and a switching element of a joint connection point and the common connection point of the resonance inductor snubber capacitor and connecting the third secondary diode, between two power supply lines is characterized by configuring the DC link capacitor bus lines in parallel. Therefore, it is possible to suppress the switching loss through, DC link bus lines, as well as there could seek miniaturization and weight reduction of the power conditioner itself by using a common capacitor of the non-polar non-polar electrolytic capacitor having a capacitor, the service life of the circuit can be extended and it is possible to greatly reduce the loss can be greatly improve the reliability of the product and the operation of the product itself.
A Study on Loss of Excitation Algorithm for Generator Field Protection
Park, Yu-Yeong ; Park, Chul-Won ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 368~372
DOI : 10.5370/KIEEP.2014.63.4.368
The most widely used scheme for detecting loss of excitation on generator is used to sense apparent impedance from generator terminals. This paper presents loss of excitation algorithm using DFT filter based negative offset mho elements for generator field protection. It`s algorithm includes two negative mho characteristics looking in the generator. The generator control system was modeled by PSCAD/EMTDC software, and then the proposed algorithm was tested by the collecting relaying signals from selected the generator model. From simulation results, the loss of excitation algorithm can be used to field protection for generator.
A Study on the Dielectric Characteristics of Non-Cross Linked Polyolefin for Distribution Power Cables
Kim, Junil ; Lee, Onyou ; Bang, Seungmin ; Kang, Jong O ; Lee, Hongseok ; Jeong, Yeong-Ho ; Kang, Hyoungku ;
The Transactions of the Korean Institute of Electrical Engineers P, volume 63, issue 4, 2014, Pages 373~377
DOI : 10.5370/KIEEP.2014.63.4.373
A cross linked polyethylene (XLPE) material has been widely used to develop a distribution power cable due to its excellent electrical characteristics and mechanical strength. However, several problems such as environmental disruption, electrical aging, thermosetting property, and impurities which cause degradation also arise. Therefore, a novel dielectric material should be developed to substitute for the XLPE. Several kinds of polyolefin materials to substitute for the conventional dielectric material, XLPE are developed and A cylindrical rod to cylindrical rod electrode system made with stainless steel is used to perform the experiments according to the ASTM D-149 protocol under an AC and Impulse input voltage condition. The experimental results are calculated by the Weibull distribution method and analyzed by an Finite Element Method(FEM). Finally, the dielectric characteristics of the conventional XLPE and novel polyolefin are experimented compared with each other in this study.