• Journal of the Korean Society for Railway
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• v.2 no.2
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• pp.39-45
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• 1999

This paper presents the current-fed inverter of a TGV-K traction system with thyristor switches using phase control and commutation techniques. The current-fed inverters have two modes of operation which consist of forced commutation and natural commutation. In forced commutation mode, at speed of less than 120km/h, commutation is forced by means of the commutation capacitors and the thyristors. Above 120km/h, the thyristors operate in natural commutation mode. according to the voltages between phases of the motors. In this paper. the power conversion theory of the TGV-K traction system and the control principle of the converter and current-fed inverter are discussed.

• 제어로봇시스템학회:학술대회논문집
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• 2005.06a
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• pp.951-956
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• 2005

Since a snake achieves various movements just by a slender body, the mechanism of it is very amazing Many researches have been focusing on a snake like robot and have done for it on the ground. However the meander motion of the snake not only can be done by ground creatures, but also can be done by a water creature such as a sea snake or an eel. Therefore, the purpose of our research is to develop an autonomous underwater robot like the sea snake. As an approach to this goal, we develop an experimental sea snake-like-robot for examining basic characteristics, including propulsion, a turning and other performance. Our developed robot is composed of the head and 4 bodies. Each body equips one servomotor, which is operated with pulse signal. In the head unit, 1- chip-microcomputer, which generates the servomotor control signal for realizing a snake motion and the battery, is equipped. Our robot is covered with a rubber film for the waterproof. Using our developed robot, characteristics of the snake-like-robot moved in water are examined.

• Journal of the Korea Institute of Military Science and Technology
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• v.17 no.5
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• pp.569-576
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• 2014

There were overwhelming high-frequency electromagnetic noises in 200kW-class hybrid electric vehicle(HEV) although EMC control strategy had been applied to cope with the electromagnetic noises during the development of HEV. This paper investigates the characteristics of the conducted and radiated emission noises, the source and path of noises, and the effects of EMI on the electronics. Finally the design concept of noise control is proposed.

• Journal of Advanced Marine Engineering and Technology
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• v.17 no.2
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• pp.29-35
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• 1993

Recent marine propulsion diesel engines tend to become slower in speed and longer in stroke for the higher engine efficiency, and in these long stroke and slow speed engines the digital governors are highly recommended to be used. But, in the present digital governors only the feedback of the engine rpm-signal is used for the engine speed control. If the load torque of the engine can be measured or estimated and the torque feedback loop is added to the present digital governor, it is expected that the speed control performance of the digital governor will be highly improved. In this paper, a new method is proposed to estimate the load torque of the diesel engine from the measured signals of fuel oil and rpm. And it is also suggested that the Kalman filter can be used for the estimation of engine torque.

• The Journal of Korea Robotics Society
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• v.11 no.4
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• pp.217-225
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• 2016

Dynamic Positioning (DP) is used to automatically maintain the position and heading of a floating structure subjected to environmental disturbances. A DP control system is composed of a motion controller to compute the desired force and moment and a thrust allocator to distribute the computed force and moment to multiple thrusters considering mechanical and operational constraints. Among various thruster configurations, azimuth thrusters or propeller/rudder pairs tend to make the allocation problem difficult to solve, because these types of propulsion systems include nonlinear constraints. In this paper, a dynamic positioning strategy for a twin-thruster ship that is propelled by two azimuthing thrusters is addressed, and a thrust allocation method which does not require a numerical optimization solver is proposed. The applicability of the proposed method is demonstrated with an experiment using an autonomous boat.

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.249-251
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• 1994

This paper introduces an implementation of high performance voltage source inverter system based on 16bit micro-processor and DSP for the application to modem rolling stock traction system. In contrast with other industry oriented inverter system, this system requires precise control action complying with various load condition and high overload capability. An asynchronous PWM generation and 3' pulse mode technology are adopted in order to improve compliant starting torque characteristics at starting phase and soft backward-forward starting motion.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.2023-2029
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• 2009

The PRT can be divided into In-Track and On-Board according to propulsion method. In process of In-Track, vehicles driven by LIMs(Linear Induction Motor) which are installed in Guideway. Central Controller, which control whole machine, must control speed and direction of all vehicles. In this case, as vehicle increases, Central Controller will overload. If Central Controller fails, all vehicle stops. To avoid this problem, processing of Central Controller must be distributed. This paper introduces method of Distributed Routing. Method of Distributed Routing will provide safety and efficiency for PRT System.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.1
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• pp.71-77
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• 2011

An analysis, which is focused on electrical losses of an electrical propulsion system with High voltage DC/DC Converter (HDC) for a hybrid and an electric vehicle, is presented. From the analysis, it can be known that the electrical losses are closely related to the dc link voltage of the HDC, and there is an optimal dc link voltage which minimizes the losses. In this paper, the method to decide the optimal dc link voltage is proposed and the comparison on the losses by the control methods of the dc link voltage, during a driving cycle, is performed and the result is also presented.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.632-637
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• 2018

AC 및 DC 전력공급구간에서 모두 주행이 가능한 AC/DC 철도차량은 추진제어장치 내부에 컨버터 및 인버터가 모두 구성되어 있다. 따라서 DC 철도차량에 비해서 구성이 복잡하며 각 전력공급 환경에 적합한 인버터 제어 방법이 요구된다. 본 논문에서는 각 전력공급구간에서 고려되어야 할 사항과 이에 대한 인버터 제어 방법에 대하여 기술하고 서울 1호선 및 4호선 철도차량에 적용한 결과를 분석하였다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.12
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• pp.1810-1817
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• 2015

The railway vehicle has an auxiliary power unit for supplying power to the associated electronic control devices and passenger service unit. Typically, input voltage from the catenary for rolling stock is highly fluctuating according to the substation capacity, vehicle propulsion and regeneration. Especially, the frost and freezing on contact wire in winter can cause a blackout inside vehicle, and also brings about electronic components damaging and the system down. To prevent this problem, a large filter and capacitor is used. But this is not a perfect solution, because it is increasing weight of the unit. In this paper, a new algorithm is proposed to suppress the disturbance without adding devices. Simulation and experimental results show that the proposed algorithm has performance to suppress the disturbance at the sudden input voltage variations.