• Title/Summary/Keyword: Stabilizer

Search Result 1,106, Processing Time 0.025 seconds

Design of an Adaptive Neurofuzzy-Based Power System Stabilizer (적응 뉴로 퍼지 전력계통 안정화 장치의 설계)

  • Jeong, Hyeong-Hwan;Jeong, Mun-Gyu;Kim, Sang-Hyo
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.50 no.11
    • /
    • pp.497-505
    • /
    • 2001
  • The power system stabilizer(PSS) is important for the suppression of low-frequency oscillation and the improvement of system stability. In this paper, An Adaptive Neurofuzzy-based Power System Stabilizer(ANF PSS) is proposed as the new PSS type. The proposed PSS employs a multi-layer adaptive network. The network is trained directly from the input and the output of the generating unit. The algorithm combines the advantages of the Artificial Neural Network(ANN) and Fuzzy Logic Control(FLC) schemes. Studies show that the proposed ANF PSS can provide good damping of the power system over the wide range of operating conditions and improve the dynamic performance of the system.

  • PDF

Suspension Polymerization of Styrene with Tricalcium Phosphate as Stabilizer

  • Hong, Soon-Gil;Park, Moonsoo
    • Macromolecular Research
    • /
    • v.8 no.6
    • /
    • pp.247-252
    • /
    • 2000
  • Suspension polymerizations of styrene were conducted in the aqueous phase with tricalcium phosphate (TCP) as a stabilizer and $\alpha$, $\alpha$'-azobis(isobutyronitrile) (AIBN) as an initiator. Various amounts of initiator and stabilizer were selected and the reaction was carried out at a selected temperature between 60 to 80 $\^{C}$. It was found that the combination of 5 wt% stabilizer and 2.427$\times$10$\^$-3/ mol/L of costabilizer is the minimum amount for suspension polymerization reaction to produce particles in the aqueous phase. Particles were found to be polydisperse in diameter, regardless of reaction conditions. Class transitions were observed to be around 95$\^{C}$, nearly independent of reaction temperature and initiator. Homogenizer was found to be essential in forming particles in the proximity of tens of micrometers in diameter in suspension polymerization with TCP as stabilizer.

  • PDF

The Effect on Wake Flow and Vortex Shedding Frequency by Vortex Stabilizer in Karman Vortex Type Air Flow Sensor (칼만와류식 공기유량센서의 와안정판이 후류유동장과 와유출주파수에 미치는 영향)

  • 임성원;류병남;이종춘;부정숙
    • Journal of Advanced Marine Engineering and Technology
    • /
    • v.25 no.4
    • /
    • pp.846-856
    • /
    • 2001
  • An experimental study has been made to investigate the effect on wake flow and vortex shedding frequency by vortex stabilizer in Karman vortex type air flow sensor. The conditions investigated include 3 types of shapes and 3 types of separation distances of the vortex stabilizer. The phase averaged technique and smoke-wire flow visualization method are used to understand the detail information. The rolling up position of shear layer is fixed by the influence of the vortex stabilizer. Especially, the convex type vortex stabilizer has shown the more stable repeatability and linearity regarding the vortex shedding frequency compared to the other types.

  • PDF

On the mechanism of vertical stabilizer plates for improving aerodynamic stability of bridges

  • Chen, Airong;Zhou, Zhiyong;Xiang, Haifan
    • Wind and Structures
    • /
    • v.9 no.1
    • /
    • pp.59-74
    • /
    • 2006
  • Vertical stabilizer plates have been found to be an effective aerodynamic measure to improve the aerodynamic stability of bridges either with an open cross section or with a streamlined box cross section in wind tunnel testings and have been adopted in some long span bridges. By taking an open deck II-shaped section and a closed box section as examples, the mechanism of vertical stabilizer plates for improving aerodynamic stability are investigated by using numerical simulation based on Random Vortex Method. It is found that vertical stabilizer plates can increase the amplitude of the heaving motion, and decrease that of the rotational motion of the bridge decks.

The Electrical Loss Analysis on the Stabilizer and Cryostat of a Superconducting Power Cable System (초전도 전력 케이블 시스템에서의 stabilizer와 외부 cryostat에서의 전기적 손실 해석)

  • Choi, S.J.;Song, M.K.;Lee, S.J.;Sim, K.D.;Cho, J.W.
    • Proceedings of the KIEE Conference
    • /
    • 2005.07b
    • /
    • pp.1246-1248
    • /
    • 2005
  • 초전도 전력케이블 시스템은 일반적으로 다음과 같은 전자기적 구조를 가지게 된다. 먼저, 여러 층으로 이루어진 전력 전송을 위한 초전도 코어, 초전도 코어 고장시 전송전류를 바이패스 시키는 stabilizer 그리고 최외각의 질소 및 진공을 위한 2층의 cryostat으로 이루어진다. 본 논문에서는 초전도 전력케이블이 정상적으로 운행될 때 내부 stabilizer 및 외부 질소조와 진공조에서 발생하는 와전류 손실을 상용전자장 해석프로그램인 opera 3d를 이용하여 모델링한 후, 각 부분에서의 와전류 손실을 도출하여 초전도전력케이블 시스템의 설계시 stabilizer와 외부 질소조 및 진공조의 제작에 그 결과를 응용하고자 한다.

  • PDF

Effects of Suspension Compliance and Chassis Flexibility in Handling Performance (현가장치의 유연성과 차체의 탄성효과가 조종안정성에 미치는 영향 분석)

  • Kang, Dong-Kwon;Yoo, Wan-Suk
    • Journal of the Korean Society for Precision Engineering
    • /
    • v.14 no.7
    • /
    • pp.137-143
    • /
    • 1997
  • In this study, handling simulation of a passenger car is carried out to see the effects of suspension compliance, roll stabilizef bar and chassis flexibility. The front suspension of the car is a MacPherson strut type and the rear suspension is a multi-link type. The following five DADS models are constructed and compared to verify the effects of suspension compliance and chassis flexibility during lane change. (1) Vdhicle model without hard point compliance and stabilizer, (2) Vehicle model with hard point compoiance, (3) Vehicle model with hard point compliance and stabilizer, (4) Vehicle model with hard point compoiance, stabilizer, and one vibration mode of the chaxxis. (5) Vehicle model with hard point compliance, stabilizer, and three vibration modes of the chassis. The result shows that hard point compliance and stabilizer are significant in roll angle, and the flexibility of the chassis affects the yaw angle and yaw rate.

  • PDF

Resistance Increase Behavior of HTS Wire with Stabilizer Layer on Applied Over-currents

  • Du, Ho-Ik;Kim, Min-Ju;Doo, Seung-Gyu;Kim, Yong-Jin;Han, Byoung-Sung
    • Transactions on Electrical and Electronic Materials
    • /
    • v.10 no.2
    • /
    • pp.62-65
    • /
    • 2009
  • YBCO-coated conductors, called "second-generation wires," show a remarkably greater increase in the amount or speed of their resistance than BSCCO wires when a quench occurs. This is probably because of the specific resistance at their stabilizer layer, which also affects their voltage grade. YBCO coated conductors with copper as a stabilizer layer have a voltage grade of 1.5-2 V/cm, and those with stainless steel as a stabilizer layer have a voltage grade of about 0.5-0.6 V/cm. The voltage grade of YBCO coated conductors is important in selecting and applying superconducting wires to power instruments later. In this study, two kinds of YBCO-coated conductors with different stabilizer layers and one kind of BSCCO wire were prepared. Among them, based on the YBCO coated conductors that had a stainless steel stabilizer layer with a low voltage grade, five kinds of experimental samples for joining were prepared with the remaining two kinds of wires. Using the prepared samples, the current application properties and the resistance increase in the flux-flow and the quench states of the single wire and the joined wires were compared.

Fabrication and characterization of fault current limiting devices made of stabilizer-free coated conductors (Stabilizer-free 초전도 선재를 이용한 한류 소자 제작 및 특성 시험)

  • Yim, Seong-Woo;Park, Chung-Ryul;Yu, Seong-Duck;Kim, Hye-Rim;Hyun, Ok-Bae
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2009.06a
    • /
    • pp.371-371
    • /
    • 2009
  • For the application of superconducting wires to fault current limiting devices, it is required that they have a high rated voltage when a fault occurs. Stabilizer-free coated conductors, particularly, shows a good performance for the high rated voltage, which is beyond 0.6 V/cm. In this study, using the stabilizer-free coated conductors, we made fault current limiting devices and examined their characteristics. Fault current limiting devices were fabricated with a shape of the cylinder of a mono-filar coil winding. Stabilizer-free coated conductors were wound along the mono-filar coil line and the terminal parts between the wire and metal were soldered using In solder. Two kinds of devices were fabricated by a different method in the terminal joint, one was made by a soldering and the other was made by a soldering-free joint. Critical currents and resistance at the joint parts were measured. In addition, long-time current flowing tests were also carried out for the characterization of the fault current limiting devices.

  • PDF

A Study on the mix design for the Soilcrete by Using FGC Soil Stabilizer (FGC계 고화재를 이용한 Soilcrete 배합설계에 관한 연구)

  • 천병식;고갑수;김진춘;하상욱
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 1999.10a
    • /
    • pp.293-300
    • /
    • 1999
  • Soilcrete has been the traditional material for the paving and soft ground improvement techniques. But because the durability is not excellent and the quality is not homogeneous, it has not been used for the various purposes up to date. And because the quality of soilcrete is apt to be changed by the content of water and soil stabilizer, and the kind of soil and soil stabilizer, it is not free of cares. But with the increase of naturally oriented needs for the light traffic road such as pedestrian roads of the garden, golf courses and sidewalks, the cases of soilcrete paving has been increased recently. This study aims at making the reference table of the mix design in accordance with the required design specifications for the soilcrete admixtures by the FGC soil stabilizer by using the statistical experiment method. The treated soil is the clay which are widely spreaded in Korea. As the results of this study we can derive the effective reference mix design table for the clay soil treated by the FGC soil stabilizer in accordance with the compressive strength of 50∼200kg/$\textrm{cm}^2$ soilcrete with respect to the contents of water, soil stabilizer and fine sand.

  • PDF

Test of Vision Stabilizer for Unmanned Vehicle Using Virtual Environment and 6 Axis Motion Simulator (가상 환경 및 6축 모션 시뮬레이터를 이용한 무인차량 영상 안정화 장치 시험)

  • Kim, Sunwoo;Ki, Sun-Ock;Kim, Sung-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.39 no.2
    • /
    • pp.227-233
    • /
    • 2015
  • In this study, an indoor test environment was developed for studying the vision stabilizer of an unmanned vehicle, using a virtual environment and a 6-axis motion simulator. The real driving environment was replaced by a virtual environment based on the Aberdeen Proving Ground bump test course for military tank testing. The vehicle motion was reproduced by a 6-axis motion simulator. Virtual reality driving courses were displayed in front of the vision stabilizer, which was located on the top of the motion simulator. The performance of the stabilizer was investigated by checking the image of the camera, and the pitch and roll angles of the stabilizer captured by the IMU sensor of the camera.