• Journal of the Korean Society for Railway
• /
• v.13 no.2
• /
• pp.166-172
• /
• 2010

Currently, vector control is used for speed control of trains because induction motor has high performance is installed in Electric railroad systems. Also, control of the induction motor is possible through various methods by developing inverters and control theory. Presently, rolling stocks which use the induction motor are possible to brake trains by using AC motor. Therefore model of motor block and induction motor is needed to adapt various methods. There is Variable Voltage Variable Frequency (VVVF) as the control method of the induction motor. The torque and speed is controlled in the VVVF. The propulsion system model in the electric railroad has many sub-systems. So, the analysis of performance of the speed control is very complex. In this paper, simulation models are suggested by using Matlab/Simulink in the speed control characteristic. On the basis of the simulation models, the response to disturbance input is analyzed about the load. Also, the current, speed and flux control model are proposed to analyze the speed control characteristic in the train propulsion system.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.15 no.4
• /
• pp.18-25
• /
• 2011

Solid propulsion systems have simple structures compared to other propulsion systems and are suitable for long-term storage. However the systems generally have limits on control of thrust levels. In this paper we suggest control algorithms for combustion chamber pressure of variable thrust solid propulsion systems using special nozzles such as pintle valve. For the pressure control within the chamber, we use a simple pressure change model by considering only mass conservation within the combustion chamber, design a classical algorithm and also a nonlinear controller using the feedback linearization technique. Also we derive the equation of the thrust for an under-expanded one-dimensional nozzle and then design a proportional-intergral controller after linearizing the thrust model for an operating point. Finally, we demonstrate the performance of the controller through a numerical simulation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2009.11a
• /
• pp.526-529
• /
• 2009

In this study, we analyze the characteristic of burning classified by a propellant according to a flux of an oxidizer to analyze propellant regression distance in accordance with a thrust control and burning time of hybrid rocket using hybrid combustor of Lab-Scale. To control a flux of an oxidizer, we design flow control system to regulate the mount of opening and shutting of a needle valve by a driving of stepping motor by a combination the needle valve with stepping motor. We derive the relationships between mass flow rate and regression rate according to a propellant through the oxidizer flux change. While doing the thrust control, we estimate regression distance through the oxidizer flux in accordance with thrust and confirm the creditability through the actual thrust control burning experimentation.

• Proceedings of the Korean Society of Propulsion Engineers Conference
• /
• 2005.11a
• /
• pp.487-490
• /
• 2005

The thrust Control in Solid Propellant Rocket is incomparably limited than that in Liquid Propellant Rocket. Because it is fixed that section to relate a combustion, that is a natural result. The control of a thrust directions in a Solid Propellant Rocket is not efficient for the purpose of a Solid Propellant Rocket. But it is a problem to solve that a weight on board should increase through the maximization of the thrust in a Solid Propellant Rocket.

• KIPE Magazine
• /
• v.16 no.3
• /
• pp.37-41
• /
• 2011

현대로템은 전기철도차량의 핵심장치인 주 전력변환장치(추진제어장치) 국산화 및 기술개발에 매진하여 왔으며, 성능 및 신뢰성 향상을 위하여 지속적으로 기술개발을 진행하고 있다. 또한 전력전자기술 및 산업기술 발전으로 인한 전기기기, 전력반도체, 제어기술 발전으로 전기철도차량용 주 전력변환장치(추진제어장치)도 비약적인 발전을 하였다. 이런 산업전반에 걸친 기술발전을 기반으로 현대로템은 전기철도차량용 주 전력변환장치의 원천기술 확보하면서 전기철도차량 시스템 기술 발전에 기여하고 있다. 본지에서는 전기철도차량의 핵심장치인 주 전력변환장치에 대한 이해를 돕고자 최근 전동차에 적용되고 있는 유도전동기용 주 전력변환장치인 추진제어장치를 소개하고자 한다.

• Journal of the Korea Institute of Information and Communication Engineering
• /
• v.21 no.9
• /
• pp.1796-1807
• /
• 2017

The domestic warship propulsion system is at the stage of a hybrid propulsion system changing from a mechanical propulsion system and the propulsion system becomes complicated so it is expected that the function of ECS(Engineering Control System) that controls and monitors the warship propulsion system becomes important. Recently the development of ECS has progressed domestically, so that verification of reliability and stability is required in the process of ECS development. The simulator to be proposed is composed of HILS, it can be divided into a shaft-line dynamics model of the simulating power transmission, a controller model of the simulating the control of the equipment, and a communication model communicating with the ECS. In this paper, we developed simulator for ECS verification for CODLOG hybrid propulsion system, set scenario, and conducted simulation.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.12 no.3
• /
• pp.41-48
• /
• 2008

One of main functions of the firing control system applied to a rocket propulsion test has been to provide electric current for ignition of a solid rocket motor. This paper describes the design and implementation of an enhanced firing control system for ground propulsion test that can also control and verify various types of squib events and flight sequences.

• ICROS
• /
• v.3 no.4
• /
• pp.33-39
• /
• 1997

본 글에서는 21세기를 대비한 차세대생산시스템으로 일컬어지는 지능형생산시스템(IMS: Intelligent Manufacturing System)의 기술 개발을 위해 국제공동연구로 진행되고 있는 "국제 IMS 프로그램"을 소개하고 우리나라의 추진현황에 대해서도 설명한다. 제 2절에서는 국제 IMS 프로그램의 개요로서 추진배경, IMS의 목표, 참가국 및 추진체계, 자금운영 방법 등에 대해 설명한다. 제 3절에서는 국제 IMS 프로그램에서 수행하는 프로젝트들을 소개하며, 국내의 IMS 추진전략 및 주요활동 등을 제 4절에서 설명한다.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2014.02a
• /
• pp.140.1-140.1
• /
• 2014

인공위성은 지상에서 발사된 후 로켓에 의해 임무궤도에 안착을 한 뒤 위성 내부에 탑재된 추진시스템에 의하여 자세 및 궤도제어를 수행한다. 특히, 저궤도 관측위성의 경우 정확한 이미지 촬영을 위해서는 자세제어가 매우 중요하고, 추진체의 잔여량에 따라 인공위성의 수명이 결정되기도 하므로 추진시스템의 역할이 매우 중요하다. 특히, 추진체의 무게에 따라 위성 전체 중량이 좌우되어 발사중량에도 영향을 미치게 되므로 고성능, 저질량의 추진계가 요구되며, 추진계는 극히 미세한 누설도 허용되지 않는다. 개발된 인공위성 추진계 내부의 누설 여부 확인을 위하여 우주환경을 모사한 진공챔버 내부에서 고압으로 충진된 추진 탱크의 누설탐지 시험을 수행하게 된다. 본 논문에서는 지상에서 모사된 우주환경 하에서 인공위성 추진계의 누설 탐지 기법에 대해 알아보고자 한다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.16 no.12
• /
• pp.8187-8194
• /
• 2015

To accelerate a heavy roller coaster train with over 1G force, a lot of thrust is required and linear synchronous motor(LSM) as propulsion method is suitable for this kind of system. To increase the propulsion efficiency of LSM, precise and real-time position information of vehicle is required for accurate phase control. However, the discontinuous position information with relatively long time interval is usually transmitted from the hall-sensors on the track every magnet length. In this paper, the basic motor model based on traditional dq-axis equations is described and the motor dynamic model is produced by considering the cogging force and friction loss. To improve the position accuracy, the position estimator is also proposed for LSM control system. Simulations were performed to check the characteristics of the torque control system which includes the position estimator based on the motor model. Simulation results based on the linearized model show that this control system has an enough bandwidth and phase margin and the executed algorithm achieves an ideal effect to follow the real-time position signal. Therefore, the feasibility of position estimator is also confirmed.