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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 62, Issue 12 - Dec 2013
Volume 62, Issue 11 - Nov 2013
Volume 62, Issue 10 - Oct 2013
Volume 62, Issue 9 - Sep 2013
Volume 62, Issue 8 - Aug 2013
Volume 62, Issue 7 - Jul 2013
Volume 62, Issue 6 - Jun 2013
Volume 62, Issue 5 - May 2013
Volume 62, Issue 4 - Apr 2013
Volume 62, Issue 3 - Mar 2013
Volume 62, Issue 2 - Feb 2013
Volume 62, Issue 1 - Jan 2013
Selecting the target year
Optimal Coefficient Selection of Exponential Smoothing Model in Short Term Load Forecasting on Weekdays
Song, Kyung-Bin ; Kwon, Oh-Sung ; Park, Jeong-Do ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 149~154
DOI : 10.5370/KIEE.2013.62.2.149
Short term load forecasting for electric power demand is essential for stable power system operation and efficient power market operation. High accuracy of the short term load forecasting can keep the power system more stable and save the power market operation cost. We propose an optimal coefficient selection method for exponential smoothing model in short term load forecasting on weekdays. In order to find the optimal coefficient of exponential smoothing model, load forecasting errors are minimized for actual electric load demand data of last three years. The proposed method are verified by case studies for last three years from 2009 to 2011. The results of case studies show that the average percentage errors of the proposed load forecasting method are improved comparing with errors of the previous methods.
A Study on the Developing Method of HIF Monitoring Data using Wavelet Coefficient
Jung, Young-Beom ; Jung, Yeon-Ha ; Kim, Kil-Sin ; Lee, Byung-Sung ; Bae, Seung-Chul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 155~163
DOI : 10.5370/KIEE.2013.62.2.155
As the increasing HIF(High Impedance Fault) with the arc cannot be easily detected for the low fault current magnitude compared to actual load in distribution line. However, the arcing current shows that the magnitude varies with time and the signal is asymmetric. In addition, discontinuous changes occur at starting point of arc. Considering these characteristics, wavelet transformation of actual current data shows difference between before and after the fault. Althogh raw data(detail coefficient) of wavelet transform may not be directly applied to HIF detection logic in a device, there are several developing methods of HIF monitoring data using the original wavelet coefficients. In this paper, a simple and effective developing methods of HIF monitoring data were analized by using the signal data through an actual HIF experiment to apply them to economic devices. The methods using the sumation of the wavelet coefficient squares in one cycle of the fundamental frequency as the energies of the wavelet coefficeits and the sumation of the absolute values were compared. Besides, the improved method which less occupies H/W resouces and can be applied to field detection devices was proposed. and also Verification of this HIF detection method through field test on distribution system in KEPCO power testing center was performed.
Development of a Novel Air-Conditioning Method for Energy Savings in Commercial Building Under Time of Use Electricity Pricing
Noh, Sung-Jun ; Jeon, Jeong-Pyo ; Kim, Kwang-Ho ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 164~170
DOI : 10.5370/KIEE.2013.62.2.164
The commercial buildings are consuming about 30% of total energy used in Korea. And a large amount of energy consumption in commercial buildings is consumed by HVAC(Heating, Ventilation, Air Conditioning) system. Therefore, if we can reduce the energy consumption in HVAC or air-conditioning system in commercial buildings, the overall energy consumption in Korea can be reduced. Currently, an electricity charge called Time of Use (TOU) is applied to typical commercial buildings. This paper proposes the novel energy management method where the temperature setting of air-conditioning system are adjusted to minimize the use of electrical energy while indoor comfort level is retained. The simulation test for a typical commercial building shows that the proposed method gives over 10% savings in electricity bills and electricity consumption compared to the conventional air-conditioning method.
The Reluctance Torque Estimate by Linkage Flux Calculation of IPMSM
Cho, Gyu-Won ; Kim, Cheol-Min ; Lee, Jung-Gyu ; Kim, Gyu-Tak ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 171~176
DOI : 10.5370/KIEE.2013.62.2.171
Classically, reluctance torque of IPMSM(Interior Permanent Magnet Synchronous Motor) by using inductance according to current phase angle generates an error. This error is affected by total torque. From current phase angle
to large errors will occur, because reluctance torque include current phase angle. But, reluctance torque from steady-state voltage equation of IPMSM is represented by linkage flux. So, reluctance torque is unrelated to the current phase angle formula can be derived. In this paper, operating torque was analyzed by d, q-axis linkage flux of IPMSM and reluctance torque to perform calculations reduced the error of the total torque calculation.
Shape Optimization of High Voltage Gas Circuit Breaker Using Kriging-Based Model And Genetic Algorithm
Kwak, Chang-Seob ; Kim, Hong-Kyu ; Cha, Jeong-Won ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 177~183
DOI : 10.5370/KIEE.2013.62.2.177
We describe a new method for selecting design variables for shape optimization of high-voltage gas circuit breaker using a Kriging meta-model and a genetic algorithm. Firstly we sample balance design variables using the Latin Hypercube Sampling. Secondly, we build meta-model using the Kriging. Thirdly, we search the optimal design variables using a genetic algorithm. To obtain the more exact design variable, we adopt the boundary shifting method. With the proposed optimization frame, we can get the improved interruption design and reduce the design time by 80%. We applied the proposed method to the optimization of multivariate optimization problems as well as shape optimization of a high - voltage gas circuit breaker.
Design and Drive Performance of Single-phase Hybrid SRM with Commercial Ferrite Permanent Magnets
Ahn, Jin-Woo ; Heo, Jae-Hun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 184~189
DOI : 10.5370/KIEE.2013.62.2.184
Compared to a multiphase SRM, a single-phase SRM has some advantages, such as lower number of switches and power converter size, which leads to gradually increasing in the household appliances and industrial applications. But the torque dead zone is existed in the single-phase SRM which decreases the starting capability of the motor and increases the torque ripple. In order to solve the aforementioned problems, a single-phase hybrid SRM with commercial ferrite permanent magnet is proposed in this paper. Basic design principle for the proposed structure is described. To verify the proposed structure, FEM is employed to get the characteristics of the proposed structure. Based on the analysis, a prototype is designed and manufactured. And, the experimental system is also constructed. The validity of the proposed structure is verified by the experimental results.
Surge Characteristics Analysis and Reduction Method of Vacuum Circuit Breaker
Kim, Jong-Gyeum ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 190~195
DOI : 10.5370/KIEE.2013.62.2.190
Vacuum circuit breaker(VCB) has been widely used for interruption of load current and fault current for high voltage motor in the industrial field. Its arc extinguishing capability is excellent compared to other breakers. But it has the potential to cause multi reignition surge by high extinguishing capability. Surge voltage is generated by the opening and closing of VCB. Multi reignition surge of VCB is steep-fronted waveform. It may have a detrimental effect on the motor winding insulation. So, most of users install a protection device to limit steep-front waveform at the motor terminal or breaker side. So, most of users install a protection device at the motor terminal or breaker side. This protective device is surge absorber(SA) such as ZnO and RC type. In this study, we analyzed whether there is any effect when two type SA is applied to the VCB multi reignition surge. We confirmed that ZnO SA is slightly more effective than RC SA for reduction of multi reignition surge.
A Development of the Electric Power Supply System for PRT Vehicle
Kim, Baek-Hyun ; Jeong, Rag-Gyo ; Chung, Sang-Gi ; Kang, Seok-Won ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 196~200
DOI : 10.5370/KIEE.2013.62.2.196
In this paper, the design of PRT vehicle power supply system is discussed. Since there is no power feeding line facilities in PRT system under development, the PRT vehicle must have its own energy storage device on board. For the energy storage device, ultra-capacitor bank is applied due to its fast charging capability and long life time. Charging the Ultra-capacitor bank is performed by wireless inductive power transfer system. The capacitor bank is charged up in less than 10 seconds when the vehicle is traveling by passenger stations. In this paper the design of the ultra-capacitor bank and the wireless inductive power transfer system for the PRT vehicle are discussed. Tests are conducted for the both system and the result shows the efficiency of the wireless inductive power transfer system is higher than 80%.
Seamless Transfer Operation Between Grid-connected and Stand-Alone Mode in the Three-phase Inverter
Lee, Wujong ; Jo, Hyunsik ; Lee, Hak Ju ; Cha, Hanju ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 201~207
DOI : 10.5370/KIEE.2013.62.2.201
This paper propose seamless transfer operation between grid-connected and stand-alone mode in the three-phase inverter for microgrid. The inverter operates grid-connected mode and stand-alone mode. Grid-connected mode is the inverter connected to grid and stand-alone mode is to deliver energy to the load from inverter at grid fault. When conversion from gird-connected to stand-alone mode, the inverter changes current control to voltage control. When grid restored, the inverter system is conversion from stand-alone to grid-connected mode. In this case, load phase and grid phase are different. Therefore, synchronization is essential. Thus Seamless transfer operation stand-alone to grid-connected mode. In this paper, propose sealmless transfer operation between grid-connceted and stand-alome mode, and this method is verified through simulation and experiment.
A Study on FTO-less Dye Sensitized Solar Cell with Ti Deposited Glass
Park, Songyi ; Seo, Hyunwoong ; Son, Min-Kyu ; Kim, Soo-Kyoung ; Hong, Na-Yeong ; Song, Jeong-Yun ; Prabakar, Kandasamy ; Kim, Hee-Je ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 208~212
DOI : 10.5370/KIEE.2013.62.2.208
Dye-sensitized solar cells (DSCs) have taken much attention due to their low cost and easy fabrication method compare to silicon solar cells. But research on cost effective DSC is prerequisite for commercialization. Fluorine doped tin oxide (FTO) which have been commonly used for electrode substrate as electron collector occupied most percentage of manufacturing cost. Therefore we studied FTO-less DSC using sputtered Ti deposited glass as photoelectrode instead of FTO to reduce manufacturing cost. Ti films sputtered on the glass for different time, 5 to 20 minutes with decreasing sheet resistance as deposition time increases. A light source illuminated to counter electrode in order to overcome opaque Ti films. The efficiency of DSC (Ti20) made Ti sputtered glass for 20 min as photoelectrode was 5.87%. There are no significant difference with conventional cell despite lower manufacturing cost.
A Study on Thermal, Mechanical and Electrical Properties as Silane Treated Epoxy/MICA Composites
Park, Jae-Jun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 213~218
DOI : 10.5370/KIEE.2013.62.2.213
In this study, epoxy/mica composite was prepared by mixing with mechanical stirrer together with homogenizer, and the effect of amino-type silane coupling agent was also studied. To reduce the viscosity without any decrement of other properties, 1,4-Butanediol diglycidyl ether (1,4-BDGE) as an aliphatic epoxy reactive diluent was introduced to the epoxy/mica composite in order to use as vanish for high voltage motor and generator stator winding. It was confirmed by scanning electron microscopy (SEM) observation that interfacial characteristics between organic epoxy and inorganic mica was modified by coupling agent treatment so that glass transition temperature increased, and tensile strength and electrical breakdown strength increased. The properties were estimated by Weibull statistical analysis and the ac electrical breakdown strength was 20.2% modified by treating silane coupling agent.
A Study on Mechanical, Electrical Properties of Epoxy/MICA Composites with MICA Filled Contents
Park, Jae-Jun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 219~227
DOI : 10.5370/KIEE.2013.62.2.219
This paper reported a study on the thermal, mechanical and electrical insulation properties of epoxy/mica composites. To investigate the effect of mica content, glass transition temperature, mechanical properties such as tensile and flexural strength, and insulation breakdown properties for epoxy composites with various contents of mica. The effect of insulation thickness on insulation breakdown property was also studied. It was observed that tensile and flexural strength decreased with increasing mica content, while elastic modulus increased as the mica content increased. AC insulation breakdown strength for all epoxy/mica composites was higher than that of neat epoxy and that of the system with 20 wt% mica was 14.4% improved. As was expected, insulation breakdown strength at
was far higher than that at
, and it was also found that insulation breakdown strength was inversely proportion to insulation thickness.
A Study on Phi Directional Monostatic RCS Reduction of the Aluminum Plate using the Oscillation System
Hwang, Joosung ; Park, Sangbok ; Jang, Sunghoon ; Cheon, Changyul ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 228~231
DOI : 10.5370/KIEE.2013.62.2.228
This paper proposes a new method that reduces RCS(rader cross section) of the aluminum plate using a oscillation system composed of a VGA(variable gain amplifier) and a phase shifter. Once the oscillation system receives the external-RF signal through a probe on aluminum plate, it makes an amplified signal with a specific phase to cancel the signal reflected from the aluminum plate. The signal transmitted from the oscillation system has the same amplitude and out of phase with the reflected signal. And it can be controlled by the VGA and the phase shifter in the oscillation system. In order to validate the performance of the proposed oscillation system, FEM simulator was used and we measured how much an amplitude of the signal reflected from the aluminum plate rotated in phi direction is reduced in an anechoic chamber.
A Study on Optimizing Energy Transfer of Capacitive Switching Antenna
Kim, Jin-Man ; Bang, Jeong-Ju ; Huh, Chang-Su ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 232~238
DOI : 10.5370/KIEE.2013.62.2.232
In this paper we describe the maximum energy transfer of CSA(Capacitive Switching Antenna). CSA which is radiated antenna system contain energy storage and switch, antenna needs to high voltage source for electrical field radiation experiment. In this experiment we employed Marx generator as a charging source. CSA can radiate electrical field more efficiently by varying antenna capacitance. The electromagnetic generation system which was using CSA has some advantages which are more simple and more effective compared to exist system. We evaluated the performance of electromagnetic wave generating system using CSA. As a result UWB gain of system is 0.47, It is higher level than exist system is 0.3. Radiated electrical field strength at 1m is 70kV/m. It is measured by D-dot sensor and gap distance is 20mm. Center frequency of CSA is approximately 25MHz. When vary the antenna gap distance from 50mm to 20mm, we can find the radiation field strength is decrease and antenna center frequency is increased. We also simulated the energy transfer efficiency to compare with experiment result. Consequentially, CSA needs to appropriate capacitance which is similar value from marx generator for maximum energy transfer, and gap is less than 1mm to increase the CSA capacitance.
Localization of Concentric Neutrals Corrosion on Live Underground Power Cable Based on Time-frequency Domain Reflectometry
Lee, Chun Ku ; Yoon, Tae Sung ; Park, Jin Bae ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 239~245
DOI : 10.5370/KIEE.2013.62.2.239
In this paper, we propose a time-frequency domain reflectometry (TFDR) based measurement method for localizing concentric neutrals corrosion on live underground power cable. It consists of two inductive couplers which can transmit the reference signal into live underground power cable and measure the reflected signals from the impedance discontinuities of concentric neutrals corrosion. In order to compensate the dispersion of the measured reflected signal via inductive coupler, an equalizer based on Wiener filtering is designed. To improve the localizing performance of concentric neutrals corrosion in the vicinity of the measurement point, the reference signal is removed from the measured reflected signals. The localization performance of the proposed method is verified by the concentric neutrals corrosion localization experiment.
Delay Dependent Stability of Time-delayed Linear Systems using New Structure of L-K Funciton
Kim, Jin-Hoon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 246~251
DOI : 10.5370/KIEE.2013.62.2.246
In this paper, we consider the stability of linear systems without delay decomposition. A less conservative result obtained without delay decomposition is strongly required since it is a basis to get an improved result by applying simple delay decomposition. Unlike the most popular Lyapunov-Krasovski(L-K) function, we consider the cross terms between variables. Based on this new structure of L-K function, we derive a delay-dependent stability criterion in the form of linear matrix inequality(LMI). Finally, we show, by well-known two examples, that our result is less conservative than the recent results.
A Performance Study on Many-core Processor Architectures with SPEC Benchmark Programs
Lee, Jongbok ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 252~256
DOI : 10.5370/KIEE.2013.62.2.252
In order to overcome the complexity and performance limit problems of superscalar processors, the multi-core architecture has been prevalent recently. Usually, the number of cores mostly used for the multi-core processor architecture ranges from 2 to 16. However in the near future, more than 32-cores are likely to be utilized, which is called as many-core processor architecture. Using SPEC 2000 benchmarks as input, the trace-driven simulation has been performed for the 32 to 1024 many-core architectures extensively. For 1024-cores, the average performance scores 15.7 IPC, but the performance increase rate is saturated.
A Study on Long Range Image Monitoring and Tracking System Using Laser Range-Gate Method in Inclement Weather Conditions
Oh, Sung-Kwun ; Yoo, Sung-Hoon ; Ku, Kyong-Wan ; Kim, Su-Chan ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 257~263
DOI : 10.5370/KIEE.2013.62.2.257
In case of image observation equipments, CCTV for short distance visual field is usually installed and operated mostly as the means of crime-prevention. However, the extensive demand for monitoring problems in case of the increase in intelligent crimes and disasters has led to the necessity of the development of long-distance observation equipments embedded with Night View functions. In case of the Night View equipments, the relevant market is set up to be focused mostly on Thermal Observation Device(hereinafter, TOD), but some shortcomings such as the limitation of image visibility and excessive maintenance cost, etc. have actually caused the necessity of new long distance Night View equipment. Moreover there might follow lots of difficulties in long-distance visualization in the event that irregular reflection is generated by minute particles in the atmosphere such as fog, smog, and dust, etc. These factors are motivate the work presented in this study. Our study is aimed at the realization of Pulsed Laser Illuminator and newly proposed Range-Gated image acquisition technology. And also the implementation of Tracker for continuous trace of the objects of interest from the obtained sequence images.
Low-power Heartbeat Detection Algorithm and Structure Using Modified CIC Filter Banks
Oh, Seung-Lee ; Jang, Young-Beom ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 264~269
DOI : 10.5370/KIEE.2013.62.2.264
In this paper, low-power heart beat detection algorithm and structure is proposed. The proposed detection algorithm utilizes filter banks to display a specific beat per minute(BPM) from the heart beat signals. Since general filter banks need a lot of computation to calculate a BPM, we propose the filter banks structure using modified CIC(Cascaded Integrator Comb) filters. It is shown that the proposed modified CIC filter banks algorithm can display the BPM from the heart beat signals precisely and efficiently.
Equivalent Circuit Analysis of Single Phase Induction Motor Considering Magnetic Saturation Characteristics
Kim, Young Sun ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 270~277
DOI : 10.5370/KIEE.2013.62.2.270
Single phase induction motor(SPIM) is used widely because it is driven by single phase source. However, the efficiency of the motor is not good due to saturation of magnetic material. To analyze the motor accurately, the magnetic saturation characteristics should be considered in analysis of equivalent circuit. In this paper, lumped parameter of circuit are derived from multi phase induction motor using method of symmetrical coordinates. Also, we presents a method for the equivalent circuit analysis of SPIM using magnetic saturation rate. The magnetic nonlinearity is considered deriving magnetizing reactance from voltage-current saturation curve. As a results, current characteristic, torque, output and efficiency are shown through analysis of equivalent circuit. A simulation results of SPIM will be used to improve the characteristics and efficiency of motor.
The Operational Characteristics of High-speed Interrupter by Fault Types
Jeong, In-Sung ; Choi, Hyo-Sang ; Jung, Byung-Ik ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 278~283
DOI : 10.5370/KIEE.2013.62.2.278
With the increasing power demands, size of the fault current in electrical grids is steadily increasing, and it exceeds the breaking capacity of circuit breakers. To effectively cope with these problems, a high-speed interrupter was suggested. The high-speed interrupter provides fault current with a bypass to a fault current limiter in case of accidents and consequently, fault current can be restricted. In this study, behavioral characteristics of high-speed interrupter were analyzed by accident types occurred in a distribution system. When accidents occurred, a and b contact of the high-speed interrupter were turned-off and then, turned-on. Accordingly, fault current flowed to the circuit connected to a current limiting element, and the fault current limiter restricted fault current to within a half-cycle. Nevertheless, the behavior of the high-speed interrupter was slowed down by a switching surge. As a result, fault current was confirmed to be restricted not to within the anticipated half-cycle, but to after a half-cycle. Moreover, the behavioral characteristics of the high-speed interrupter changed not only by accident types, but by behaviors of R, S, and T phases. This was due to the errors in stroke lengths of the high-speed interrupters, which resulted in a slight time discrepancy among three interrupters. In addition, the switching behaviors of the b and a contact were confirmed not to have coincided due to the switching surge; b contact behaved first and a contact followed. because of this, accuracy of stroke length and switching surges through the solenoid suction increases may be necessary to resolve.
Influence of Substrate Temperature on the TiC Thin Films Prepared by Unbalanced Magnetron Sputtering Method
Park, Yong-Seob ; Lee, Jae-Hyeong ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 284~287
DOI : 10.5370/KIEE.2013.62.2.284
In this work, we have fabricated TiC films by using unbalanced magnetron sputtering method with graphite and Ti targets for contact strip application of electric railway. TiC films were deposited with various substrate temperatures. We investigated various properties of TiC films prepared with various substrate temperatures, such as the hardness, surface roughness, friction coefficient, resistivity, FESEM (Field Emission Scanning Electron Microscopy), HRTEM (High Resolution Transmission Electron Microscopy) and XPS (X-ray Photoelectron Spectroscopy). The hardness and friction coefficient properties of TiC films were improved with increasing substrate temperature. These results indicate that the improvement of hardness and resistivity is related to the increase of sp2 clusters in TiC films. And also, the resistivity value of TiC films were decreased with increasing substrate temperature.
The Life Cycle Cost Estimation for Domestic Products Motor Block of KTX-1 Considering Periodic Maintenance
Yun, Cha-Jung ; Noh, Myoung-Gyu ; Kim, Jae-Moon ;
The Transactions of The Korean Institute of Electrical Engineers, volume 62, issue 2, 2013, Pages 288~292
DOI : 10.5370/KIEE.2013.62.2.288
This paper presents the result of life-cycle cost (LCC) estimation for domestic products propulsion control system (motor block unit) of KTX-1 considering periodic maintenance. Life cycle costing is one of the most effective approaches for the cost analysis of long-life systems such as the KTX-1. Life cycle costing includes the cost of concept design, development, manufacture, operation, maintenance and disposal. To estimate LCC for domestic products motor block unit, it was analyzed physical breakdown structure (PBS) on motor unit in view of maintenance cost and unit cost etc. As a results, life cycle cost on motor block unit increased moderately expect for periodical time when major parts are replaced at the same time. hereafter this results will be reflected in the domestic products being developed.