• Title/Summary/Keyword: Surge Control

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Fuel Spiking Test for the Surge Margin Measurement in a Gas Turbine Engine (연료 돌출 시험에 의한 가스터빈엔진의 서지마진 측정)

  • Lee, Jin-Kun;Lee, Kyung-Jae;Ha, Man-Ho;Kim, Chun-Taek;Yang, Soo-Seok;Lee, Dae-Sung
    • Journal of the Korean Society of Propulsion Engineers
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    • v.8 no.2
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    • pp.18-24
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    • 2004
  • A fuel spiking test was performed to measure the surge margin of the compressor in a gas turbine engine. During the test, fuel spiking signal is superposed on the engine controller demand signals and the combined signals are used to control a fuel control valve. For the superposition, a subsystem composed of a fuel controller and a function generator is used. The real engine test was performed at the Altitude Engine Test Facility (AETF) in Korea Aerospace Research Institute (KARI). In the preliminary test, the fuel spiking signals are in good agreement with the dynamic pressure at the fuel line and at the compressor discharge point. After the preliminary test, a fuel spiking test to measure the surge point at a specific engine speed was performed. The test results show that the fuel spiking test is very effective in the measurement of surge.

Practical Civil UAV Engine Control using High-gain Observer (고이득 관측기를 이용한 실용형 민수 무인항공기 엔진 제어)

  • Jung, Byeong-In;Ahn, Dong-Man;Hong, Gyo-Young;Hong, Seung-Beom;Min-Seok, Jie
    • Journal of Advanced Navigation Technology
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    • v.15 no.6
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    • pp.1187-1193
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    • 2011
  • In this paper, proposed controller preventing compressor surge and reducing the acceleration time of the fuel flow control system for turbo-jet engine. Turbo-jet engine controller is designed by applying fuzzy PID control algorithm and high-gain observer. Observer is used to estimate to compressor rotation speed of turbo-jet engine. Result of fuzzy inference is used as the fuel flow control inputs for preventing compressor surge and flame-out in turbo-jet engine. The controller is designed to converge to the desired speed quickly and safely. Using MATLAB to perform computer simulations verified the performance of the proposed controller.

Study on the Characteristics of Control by High Frequency ECU for Braking System (제동 시스템을 위한 고주파수 ECU의 제어 특성 연구)

  • Yeon, Kyu-Bong;Chong, Jong-Wha
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.6
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    • pp.2428-2434
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    • 2012
  • This paper describes the control of a solenoid valve of ESC(Electronic Stability Control) with hydraulic modulator in braking system. ESC ECU(Electronic Control Unit) to control the high-frequency control and slope control method was applied, the surge pressure and EMI(electromagnetic interference) reduction characteristics were studied. The stage of ECU output was added the slope shaping function to reduce electromagnetic emission at higher frequencies. Measurements show that this high frequency ECU manages to reduce the surge pressure and electromagnetic emission by the control of solenoid valve. In conclusion, by using the results of this study for the high frequency ECU control, we could expect enhancement of braking system performance.

REffects of Surge Protective Devices with Respect to Types of System Grounding and Wiring Methods (전원계통의 접지방식 및 배선방식에 따른 서지보호기의 효과)

  • 이수봉;이복희;길형준
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.18 no.2
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    • pp.90-99
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    • 2004
  • High speed info-communications equipment are required with development of highly information-oriented society, the intelligent industrial facilities and social systems such as administrative, financial and traffic systems, are gradually becoming to automation, which are composed of the integrated circuits and micro-semiconductors, remote control and operation. Thus modern micro-electronic circuits can frequently be damaged by lightning surge. The protection of electronic circuits from lightning overvoltages is concentrated very interesting. In this paper, for the purpose of providing the effective protection method of electronic devices such micro-computers from lightning surges in a residential building, the protection effect of surge protective devices according to types of system groundings were experimentally analyzed. Also the effective installation method of surge protective devices was examined and proposed. The installation of SPDs in retrofits was a high remnant voltage across the protected device owing to the inductance in the long wires to the SPDs. Finally the method of installing the SPD by twisted pain wires is remarkably effective for fast rising transient overvoltages.

Analysis of Flood due to Storm Surge at Masan Bay (마산만에서 고조로 인한 침수원인 분석)

  • 황호동;이중우;권소현
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • 2004.04a
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    • pp.217-224
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    • 2004
  • Open-coast storm surge computations are of value in planning and constructing engineering works, especially in coastal regions. Prediction of typhoon surge elevations is based primarily on the use of a numerical model in this study, since it is difficult to study these events in real time or with use of physical models. A simple quasi-two dimensional numerical model for storm surge is considered. In order to understand the model's underlying assumptions, range of validity, and application, we discussed several aspects of typhoons and the physical factors governing storm generation processes. We also followed the basic governing equation, together with the assumption generally taken in their development, to see the principle characteristics of the model from a physical as well as a mathematical point of view. The equations consistent with the model described here are reduced forms of the basic equations and their effects on the resulting numerical scheme are discussed. Finally we applied the model discussed above to a storm surge problem at Masan Bay, the south coast of Korea Effects of astronomical tide, initial water level, and atmospheric pressure setup are considered. We then analyzed the flood at the coastal city and proposed a reasonable way of flood control.

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Active Stabilization for Surge Motion of Moored Vessel in Irregular Head Waves (불규칙 선수파랑 중 계류된 선박의 전후동요 제어)

  • Lee, Sang-Do;Truong, Ngoc Cuong;Xu, Xiao;You, Sam-Sang
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.5
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    • pp.437-444
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    • 2020
  • This study was focused on the stabilization of surge motions of a moored vessel under irregular head seas. A two-point moored vessel shows strong non-linearity even in regular sea, owing to its inherent non-linear restoring force. A long-crested irregular wave is subjected to the vessel system, resulting in more complex nonlinear behavior of the displacement and velocities than in the case of regular waves. Sliding mode control (SMC) is implemented in the moored vessel to control both surge displacement and surge velocity. The SMC can provide a closed-loop system with performance and robustness against parameter uncertainties and disturbances; however, chattering is the main drawback for implementing SMC. The goal of minimizing the chattering and state convergence with accuracy is achieved using a quasi-sliding mode that approximates the discontinuous function via a continuous sigmoid function. Numerical simulations were conducted to validate the effectiveness of the proposed control algorithm.

Analysis of inverter switched snubber using N-channel MOS-FET

  • Suzuki, Taiju;Ikeda, Hiroaki;Mizutani, Yoko;Ishikawa, Jinichi;Yoshida, Hirofumi
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10a
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    • pp.207-210
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    • 1996
  • This paper describes the analysis of the operation of the switched snubber in order to depress the surge voltage in the MOS-FET inverter. In this paper, the N-channel MOS-FET which operates faster than the P-channel MOS-FET was used for the inverter circuit. So, the inverter and switched snubber can operate at high-frequency in the order of MHz. The cause of generating the surge voltage in the high frequency inverter has been cleared, and then how to depress the surge voltage using the switched snubber consisting of an N-channel MOS-FET has been given. Furthermore, described is the power loss within the switched snubber which is made of an N-channel MOS-FET. The inverter having the N-channel MOS-FET used as a switched snubber can drive such a low impedance load such as mega-sonic transducer for a mega-sonic studied cleaner sufficiently.

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A Study on Absorption Device of Surge Rising Pressure Occurring when Suddenly Braking Action in the Hydraulic Driving Part of Textiles Let off (섬유송출 유압구동부 급제동시 발생하는 충격상승압 흡수장치에 관한 연구)

  • 이재구;김정현;김도태;김성동;정선환
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.12 no.1
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    • pp.84-91
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    • 2003
  • The equipment of textiles let off is a part of inspection machine which inspects finished textiles and it checks up textiles through that. This study suggests a method to select the capacity and initial gas pressure of accumulator to control surge rising pressure occurring when suddenly braking action to a desired degree. An accumulator in hydraulic systems is by hydraulic machinery which stores kinetic energy of inertia body during braking. A series of computer simulations were done for the brake action The results of the simulation work were compared with those of experiments.

Influence of $TiO_2$ Addition on Microstructure of ZnO Ceramic Varistor (ZnO 세라믹 바리스터의 미세구조에 미치는 $TiO_2$의 영향)

  • 소병문;홍진웅
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.3
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    • pp.214-220
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    • 1998
  • ZnO varistors are characterized by the features of excellent nonlinearity and surge withstand capability. In this paper, in order to investigate the use of ZnO varistor as surge absorption device in low voltage, metal oxide material($TiO_2$) was selected as control material of grain growth. Samples of ZnO varistors were fabricated with varying the contents, and then the microstructures and V-I characteristics were measured. It was observed by SEM that the mean grain size increased with the increase of the additive. From the measurement of V-I characteristics, it was observed that according to the increase of the quantity of $TiO_2$ as additive, the operating voltage was lowered.

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The Installation Technique of Grounding Electrode Conductors for Metal Oxide Distribution Surge Arresters (배전용 피뢰기의 접지도선 설치기법)

  • Lee, B.H.;You, I.S.;Lee, T.R.;Ahn, C.H.;Youn, J.S.;Youn, H.H.;Kim, J.S.;Kim, J.C.
    • Proceedings of the KIEE Conference
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    • 2001.07c
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    • pp.1718-1720
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    • 2001
  • The route of surge arrester connection is very important because bends and kinds of leads increase the impedance to lightning surges and tend to nullify the effectiveness of a grounding electrode conductor. There is a need to know how effective installation of lightning surge arresters is made in order to control voltage and to absorb energy at high lightning currents. The effectiveness of a grounding conductor and bonding for 18[kV] metal oxide distribution line arresters was experimentally investigated with lightning and oscillating impulse voltages.

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