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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korea Society For Power System Engineering
Journal Basic Information
Journal DOI :
The Korea Society for Power System Engineering
Editor in Chief :
Volume & Issues
Volume 15, Issue 6 - Dec 2011
Volume 15, Issue 5 - Oct 2011
Volume 15, Issue 4 - Aug 2011
Volume 15, Issue 3 - Jun 2011
Volume 15, Issue 2 - Apr 2011
Volume 15, Issue 1 - Feb 2011
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Simulation on Characteristics of Constant Power Regulator Systems in Variable Displacement Axial Piston Pump
Lee, J.M. ; Park, S.H. ; Park, Y.H. ; Lee, H.H. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 5~12
DOI : 10.9726/kspse.2011.15.2.005
In this study, modeling and numerical simulations has been performed to investigate performance characteristics of constant power regulator system for swash plate type axial piston pump. The commercial numerical simulation software, AMESim was applied for analyzing the dynamic behavior of constant power regulator system of swash plate axial piston pump. The validity of simulation model of constant power regulator system is verified by comparing simulation results with experiments. Also, the behavior of main components of constant power regulator system such as spool, sleeve and counterbalance piston is investigated using the results of computer simulation.
Study on characteristics of noncontact vibrating displacement sensor
Cho, C.W. ; Cho, S.T. ; Yang, K.H. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 13~18
DOI : 10.9726/kspse.2011.15.2.013
This thesis is about the result of conducting a specific experiment for the development of noncontact vibration displacement sensor for measuring the spindle vibration that is used for conditional monitoring of machinery. One should be careful when using the eddy current type displacement sensor because the sensitivity of it is different according to the quality of the material. While the probe used for nondestructive inspection adopts the effect of transmitting the material by using the high frequency domain, the eddy current type displacement sensor uses the lower frequency of around 1MHz. Also, while the nondestructive probe uses the method of enhancing output by using the resonance zone, the vibration displacement sensor utilizes the stable zone by avoiding the resonance zone. Since the oscillator of the converter uses the "L" element as Probe, its characteristic changes with the variation of a relevant impedance. In other words, if the length of Probe's Cable gets extended (Impedance increase), the sensitivity declines accordingly. The effect of surrounding temperature was small, but the influence of the quality of Sensor Coil used was high. Moreover, following an experimental demonstration of the phenomenon where the sensitivity decreases as the frequency of the tested material increases from a frequency response test, the maximum frequency that could be measured was approximately 1KHz. It was noted that the degree of precision could be maintained by using the gap of the probe in the linear zone at the installation site.
Control simulation of MR damper for a cruise bus including the virtual dynamic damper
Park, S.J. ; Sohn, J.H. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 19~24
DOI : 10.9726/kspse.2011.15.2.019
In this study, a control method of MR(magneto-rheological) damper for a cruise bus is investigated. A virtual dynamic damper and a sky-hook algorithm are employed to control the damping characteristics of MR damper. Coefficients for a virtual dynamic damper are determined through the parameter identification. A quarter car model of a cruise bus is established by using ADAMS/Car program for the computer simulation. Sine wave excitation and random excitation are used to compare the controlled MR damper with the passive damper. From the simulation results, the performance of MR damper with a virtual dynamic damper is better than that of the passive damper.
Experimental Study on Fresh Water Generation System with Low Pressure Evaporation
Chung, Han-Shik ; Wibowo, Supriyanto ; Lee, Gyeong-Hwan ; Shin, Yong-Han ; Jeong, Hyo-Min ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 25~30
DOI : 10.9726/kspse.2011.15.2.025
A fresh water generation system is designed for converting brackish water or seawater into fresh water. In this paper fresh water generation by distillation process that evaporates feed water and subsequently condenses vapor as evaporation product to get fresh water was studied and city water was employed as feed water. The system uses the ejector to create a vacuum, under which liquid can be evaporated at lower temperature than it at normal or atmospheric condition, hence less energy consumption. The effect of various operating conditions i.e. temperature of feed water and different orifice diameters were studied experimentally to investigate the characteristic of the system. It was found that these parameters have significant effect in the performance of fresh water generation system with low pressure evaporation.
Analysis of the turbulent flow on the periodically arranged semi-circular ribs in a rectangular channel
Lee, G.H. ; Nine, Md.J. ; Choi, S.H. ; Jeong, H.M. ; Chung, H.S. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 31~36
DOI : 10.9726/kspse.2011.15.2.031
The flow characteristics on the periodically arranged semi-circular ribs in a rectangular channel for turbulent flow have been investigated numerically. The aspect ratio of the rectangular channel was AR=5, the rib height to hydraulic diameter ratio was 0.07 and rib height to channel height ratio was e/H=0.117. The v2-f turbulence model and SST k-
turbulence model were used to find the flow characteristics of near the wall which are suited for realistic phenomena. The numerical analysis results show turbulent flow characteristics and pressure drop at the near the wall as observed experimentally. The results predict that turbulent kinetic energy(k) is closely relative to the diffusion of recirculation flow, and v2-f turbulence model simulation results have a good agreement with experimental.
The characteristics of capacity control using a variable speed compressor in an industrial cooler
Baek, S.M. ; Moon, C.G. ; Yoon, J.I. ; Jeong, S.K. ; Kim, E. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 37~41
DOI : 10.9726/kspse.2011.15.2.037
This paper presents the capacity-control characteristics in an industrial cooler with a variable speed compressor. The inverter-type compressor is controlled by the rotational speed of the operational frequency. This type of the compressor performs the wide range of load compared to the on-off type. When the load of the system reduces, the rotational speed will be reduced. Thus, the system leads to the less power consumption and extends the longer durability of the compressor. With the variable rotational speed of the compressor the cooling capacity of the cooler is about 1.6-3.6 kW and the capacity control is about 40-100%. The system showed the highest efficiency when the rotational speed is about 45-70 Hz. The results can be used as the basic design data to control an industrial cooler.
The Effect of Alloying Elements and Heat Treatment on the Uniform Corrosion of 440A Martensitic Stainless Steel(I)
Kim, Y.C. ; Kang, C.Y. ; Jung, B.H. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 42~48
DOI : 10.9726/kspse.2011.15.2.042
440A martensitic stainless steels which were modified with reduced carbon content(~0.5%) and addition of small amount of nickel, vanadium, tungsten and molybdenum were manufactured. Effects of alloying elements and tempering temperatures on the uniform corrosion in the solution of lN H2S04 were investigated through the electrochemical polarization test. When tempering temperature is constant, corrosion current density in active-passive transition point, Icorr, decreased a little with an increase of austenitizing temperature. In addition to this, when austenitizing temperature is constant, longer holding time showed a little lower Icorr and Ipass, passive current density. And when austenitized at
and tempered in a range of
, best anti-corrosion properties were obtained at
tempering temperature while worst at
. The specimens tempered at below
, similar and good anti-corrosion characteristics were obtained regardless of alloying elements added, showing anti-corrosion characteristics are influenced more by tempering temperature than by alloying elements.
Effect of tempering treatment on the mechanical properties in 12Cr heat resistant steel with ferrite phase
Kang, C.Y. ; Lee, S.M. ; Cho, Y.K. ; Byun, S.S. ; Jung, B.H. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 49~54
DOI : 10.9726/kspse.2011.15.2.049
Effect of tempering treatment on the mechanical properties of 12Cr heat resistant steel with ferrite phase was investigate in this study. As time and temperature of tempering treatment were increase, C and Cr contents in matrix structure were decreased. Due to increase of the amount of Cr26C6 type carbides. It was confirmed in mechanical properties experimental that tensile strength and hardness were decreased, while elongation and impact value were, increased with increasing the time and temperature.
Development of an Urea Sensor using Electric Conductivity Method
Choi, B.C. ; Kim, K.Y. ; Yang, J.Y. ; Kim, H.N. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 55~60
DOI : 10.9726/kspse.2011.15.2.055
The popularity of diesel engines is derived primarily from their higher thermal efficiency resulting from higher compression ratio. NOx removal from the diesel emissions is very important to meet stringent emission regulations. NOx emission from diesel engines is removed by an urea-SCR or an LNT system. The urea-SCR system needs the urea-solution supply system with concentration and level sensor. This study was carried out to develop a sensor for the measurement of urea-solution concentration by an electric conductivity method. Considering experimental parameters were the material of electrode, two kinds of electric power(AC or DC), the distance between two electrodes, and the length of electrode. It was found that the AC electric power was more useful to measure the urea-solution concentration compared to DC, because it prevented an ionization of the urea-solution. The silver rod coated with Pt is the most useful electrode, tendency of which is similar to Pt rod, and the cost is more economic. We could also find out the optimum distance between two electrodes and the length of electrode was 10mm and 3mm, respectively.
Effect of Welding Condition on Tensile Properties of Friction Stir Welded Joints of Al-7075-T651 Plate
Kim, C.O. ; Kim, S.J. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 61~68
DOI : 10.9726/kspse.2011.15.2.061
This paper investigates the tensile properties of the friction stir welded joints of Al 7075-T651 aluminum plate according to the welding conditions. A 7075-T651 aluminum alloy plate with a thickness of 6.0 mm was used in this investigation. For the friction stir welding (FSW) process, a tool with shoulder diameter of 20 mm and probe diameter of 9 mm was used. The rotation speed and traverse speed conditions were changed in this study, the other welding conditions are constant. The welding direction was aligned with the material rolling direction, and dimension of the FSW plate were
. As far as this work is concerned, the optimal FSW conditions are determined as the rotation speed, 600 rpm and traverse speed 0.8 mm/sec or the rotation speed, 800 rpm and traverse speed 0.5 mm/sec.
Identification and Control of Position Control System for Electro-Hydraulic Actuator (EHA)
Park, Y.H. ; Park, S.H. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 69~77
DOI : 10.9726/kspse.2011.15.2.069
In this paper, an optimal PID sliding mode controller is proposed for the position control of electro-hydrostatic actuator(ERA) systems with system uncertainties and saturation in the motor. An ERA prototype is developed and system modeling and parameter identification are executed. Then, optimal PID and optimal anti-windup PID controller are designed based on identified system model by using optimization toolbox in MA TLAB/Simulink and the performance of the two control systems are compared by experiment. It was found that the optimal anti-windup PID control system has better performance than the optimal anti-windup PID control system.
Comparison Analysis on Efficiency and Operating Characteristic between Induction and BLDC Motor according to the Load Variation Based on Battery Power Source for Electric Propulsion System of Small Ships
Yeong, T.Y. ; Jeong, S.K. ;
Journal of the Korea Society For Power System Engineering, volume 15, issue 2, 2011, Pages 78~83
DOI : 10.9726/kspse.2011.15.2.078
This paper aims at investigation some operating characteristics and energy usage efficiency of a induction motor and a BLDC motor considering electric propulsion system in a small ship based on battery source. At first, performance curves of discharge voltage from the battery and current from each motor according to the load variations were analyzed. Next, variations of motor torque and rotational speed versus load change at each motor were analyzed. Finally, efficiency of energy usage of the battery and available navigation distance were compared each other. Through some comparisons and analyses, it was cleared that the BLDC motor is more suitable for the motor of the electric propulsion system in small ships based on battery source. It is expected that the results can be used as useful data for design of the electric propulsion system with batteries.