• Journal of Advanced Marine Engineering and Technology
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• 제36권7호
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• pp.942-947
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• 2012

As electricity has been used in ship's propulsion, it is necessary to increase the system voltage and current for the electrical distribution system. So it is required to improve the system safety and efficiency, the power stability, the efficiency of the generation through various analysis of ship's electric power system. In this paper, the electrical service reliability of the power distribution system of semi submersible drilling rigs has been analysed and discussed using ETAP.

• 한국마린엔지니어링학회:학술대회논문집
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• 한국마린엔지니어링학회 2005년도 전기학술대회논문집
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• pp.1113-1119
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• 2005

The power electric system is one of the most concerning factor for the reliability of the electric propulsion ship. operation in higher temperature decreases the device's reliability and power efficiency. the management of power loss and temperature of switching devices is indispensable for the reliability fo the power electric system. In this paper, IGBT chip of the switching devices is modeled and MIIR(Motor with Inverter Internal to Rotor)type of the propulsion motors is used. these parts interact with each other to calculate the loss and temperature of device. calculated Results is modeled and designed of the control and monitoring system for the electric propulsion system.

• 전기학회논문지
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• 제64권7호
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• pp.971-977
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• 2015

The electric propulsion system requires more reliability and safety than the conventional propulsion system because any sudden changes of electric system would bring tremendous effects on the ship's safety and propulsion. So it is very important to consider the potential transient effects. This paper discusses one of the worst electric accident. That is, one or two of generators are out of service in normal seagoing condition. And the appropriate measures are simulated in order to prevent the frequency decline that can bring the other generator's tripping. In addition, the relation between the transient effects and the major factors(inertia of generator/motors, governor's drooping characteristic and response speed) are also identified using the ETAP software.

• 한국정보통신학회논문지
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• 제25권5호
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• pp.709-718
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• 2021

최근 선박의 환경오염에 대한 규제가 강화됨에 따라 하이브리드형 전력체계를 갖춘 전기 추진 선박과 같은 스마트 선박에 대한 관심이 높아지고 있다. 전기추진선박에서 사용되는 배터리는 차량 등에 사용되는 배터리보다 용량이 크므로, 가격이 높아지고 유지 보수 측면이 중요하게 여겨진다. 선박용 배터리는 일체형으로 제작되어 배터리관리 시스템에 의해 관리되며, 배터리의 유지·보수는 배터리의 교체를 통하여 이루어진다. 본 연구에서는 배터리의 용이한 관리를 위해서 예비-셀을 적용한 배터리 모듈과 제어 알고리즘을 설계 및 구현한다. 또한, 전기추진선박 전력 체계 제어에 필요한 데이터를 전력 제어 시스템에 송신 할 수 있도록 제어기를 설계한다. 해당 예비-셀을 적용한 배터리를 사용할 경우 선박 및 배터리 시스템의 안정성이 높아지며, 유지 및 보수 측면에서 이점을 가질 수 있다.

• Journal of Advanced Marine Engineering and Technology
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• 제27권5호
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• pp.548-554
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• 2003

• 대한조선학회논문집
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• 제61권1호
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• pp.19-28
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• 2024

Environmental regulations are becoming more stringent in response to climate change, especially concerning marine pollution caused by ship emissions. Large ships are adjusting by integrating technologies to reduce pollutant emissions and transitioning to eco-friendly fuels such as low-sulfur oil and LNG. However, small ships face space constraints for installing LNG propulsion systems and the risk of power depletion with pure electric propulsion. Consequently, there's growing interest in researching hybrid propulsion methods that combine electricity and diesel for smaller vessels. Hybrid propulsion systems utilize diverse energy sources, requiring an effective method for evaluating their efficiency. This study proposes employing Bond graph modeling to comprehensively analyze energy dynamics within hybrid propulsion systems, facilitating better understanding and optimization of their efficiency. Modeling of the ship's energy system using Bond graphs will be able to provide a framework for integrating various energy sources and evaluating their effects.

• 한국항해항만학회지
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• 제42권6호
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• pp.437-445
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• 2018

국제해사기구(IMO)에서는 해양 환경보호를 위해 황산화물($SO_X$), 질소산화물($NO_X$), 이산화탄소($CO_2$) 등의 선박 배기가스 배출 규제를 강화하고 있으며, 특히 미국, 유럽을 중심으로 배출가스통제구역(Emission Control Area, ECA)을 설정하여 운용하고 있다. 이러한 환경 규제의 대응방법으로서 친환경 고효율 선박에 대한 요구가 커지면서 배출가스를 줄일 수 있는 전기추진시스템 관련 연구 및 기술에 대한 관심이 늘어나고 있다. 컨테이너선과 같은 상선은 경제속도 운항의 이유로 전기추진시스템의 적용대상에서 벗어나 있었으나, 앞으로 배기가스 배출 규제가 강화되고 4차 산업혁명 기술로 대표되는 빅데이터, IoT 기술을 적용한 자동화 시스템이 선박에 적용되기 위해서는 모니터링 및 제어가 쉬운 전기추진시스템이 필요할 것으로 전망된다. 따라서 본 논문에서는 6,800TEU 컨테이너 선박을 대상으로 전기추진시스템을 적용하기 위해서 기존 컨테이너 선박의 부하분석을 통해 부하분석 기반의 발전기 및 배터리 용량 설계를 목표로 연구를 진행하였다. 부하분석기반으로 설계된 시스템은 배터리를 이용한 부하분배제어를 통해 발전기가 높은 효율구간에서 운용할 수 있다는 장점이 있다.

• 대한조선학회논문집
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• 제44권3호
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• pp.238-247
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• 2007

This paper presents the thrust loss suppression algorithm in the electric propulsion ship. The thrust loss due to cavitation can be regarded as the disturbance torque. The disturbance torque is estimated by means of the disturbance observer. Considering the estimated disturbance torque, the speed reference of the propeller is modified to suppress the thrust loss. The experimental results which performed in the cavitation tunnel with electric machine operating system and its controller will be shown to verify the proposed algorithm.

• 수산해양기술연구
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• 제50권1호
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• pp.75-82
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• 2014

In vibration analysis of ships, the principle aim is to determine the natural frequencies and excitation frequencies, and use this information to avoid resonances and vibration damage. The simplest method is to prevent resonance conditions, which is effective as long as the natural frequencies and excitation frequencies can be regarded as independent from environmental conditions. For ships that use electric propulsion systems, the sources of vibration are reduced compared with those caused by a diesel engine or other combustion-based propulsion systems. However, the frequency spectrum of these vibrations may be different; therefore, to understand the characteristics of the electric propulsion, we also should investigate how the ship responds to these vibrations. We focused on a 1,000-ton deadweight (DWT) ocean-research vessel using an electric propulsion system and analyzed the response to vibration.

• 한국수소및신에너지학회논문집
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• 제35권2호
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• pp.230-239
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• 2024

Efforts are being made to replace ship diesel engines with electric propulsion motors in response to emission regulations. In particular, in the case of short-range small ships, research is being conducted to replace polymer electrolyte membrane fuel cells (PEMFC) with power sources. However, PEMFC has problems such as slow dynamic response characteristics and reduced durability at high temperatures. To solve this problem, a high-precision ship model was developed with power distribution and thermal management strategies applied, and through this, the required power, heat, and power characteristics of the propulsion system according to the ship's speed profile were analyzed.