• Journal of Advanced Marine Engineering and Technology
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• v.40 no.1
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• pp.34-38
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• 2016

Recently, electric propulsion systems are been increasingly used in large cruise ships and merchant vessels. When abnormal electrical conditions occur in the motor of an electric propulsion ship, they can cause serious damage to the motor and propeller shaft. Research on abnormal conditions of propulsion motors used in electric propulsion vessels and electric ships difficult to find. In this study, a mathematical model of the electric propulsion system is proposed to analyze transient phenomena that occur in the case of electric propulsion motor or propeller shaft malfunction. A synchronous motor was used in the MATLAB computer simulation of this study. In the event of electrical malfunction of the electric propulsion motor at rated operation, over current occurs in the condition of 1 phase ground, over torque occurs at 3 and 2 phases ground and over current and torque occur when exciting power fails at rated operation.

• Proceedings of the KIPE Conference
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• 2011.07a
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• pp.234-235
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• 2011

본 논문에서는 직렬형 하이브리드 전기추진 시스템을 탑재한 선박에서 엔진 연료절감 및 동적 운항성능 개선을 위한 에너지 저장장치의 도입 필요성과 운용 방안을 제안하였다. 수MW급 전기추진 선박을 대상 모델로 하여 엔진-발전기 시스템의 전력사용 패턴을 분석하였고, 제안한 시스템의 효용성을 시뮬레이션을 통해 검증하였다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.17 no.1
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• pp.83-88
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• 2011

There are various environmental conditions under which ship may navigate over ocean or in harbor. Ship's torque and speed change frequently under the voyage conditions. In this case, harmonics is created in the electrical power systems. The major adverse impacts of voltage and current harmonics in the electrical power systems on generator, transformer, converter, inverter and propulsion motor lead to the increase of machine heating caused by iron and copper losses which are dependent on frequency. In this paper, an analysis of THD(total harmonic distortion) for currents and voltages in the propulsion equipment was carried out. The THD and torque ripple in the input currents of the propulsion motor have been confirmed by the simulation results.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.110-111
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• 2019

본 논문은 DC 배전 전기 추진 시스템으로 건조된 10톤급 소형 어선을 운항하며 계측한 실험 결과를 제시한다. DC 배전 선박과 모의된 AC 배전 선박을 일반적인 10톤급 소형 어선의 운용 패턴에 따라 운항하였고, 각 경우의 연료소모량을 유량계로 측정하였다. DC 배전 시스템은 가변속으로 인한 엔진의 효율적인 운전과 전기설비 무게 감소로 인한 추진 부하 감소의 효과로 AC 배전 시스템에 비하여 연료사용량이 약 20% 가량 절감된다. 실험 결과, DC 배전 전기 추진 선박을 적용할 시 연간 약 18,500L (22.0%)의 연료가 절감되어 연료비가 매년 약 1400만원 가량 절약될 것으로 예상된다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.6
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• pp.856-866
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• 2021

The increasing international awareness regarding air pollutant reduction has resulted in increasing demand for eco-friendly ships; hence, electric ships are being actively developed by various countries. Presently, studies on electric ships are mainly focused on electric propulsion systems and electric motors. However, from the ship perspective, there are no studies on conceptual designs for coastal car ferries powered by removable power supply systems. In the present study, the main research consideration is regarding the conceptual design of a fully electrified car ferry using a battery-based removable system as the main power source. By analyzing the dimensions of more than 100 domestic coastal car ferries, the main criteria satisfying the requirements for developing a suitable vessel were derived, and a study on intact/damage stability was conducted considering the application of a removable battery truck. Further analyses of the problems concerning the conceptual design were also performed to derive solutions.

• Proceedings of the KIEE Conference
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• 2008.04c
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• pp.13-15
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• 2008

본 논문은 대형(MW 급) LNG 전기추진선박 시스템의 동적 정적 특성에 대해 다룬다. 특히, 선박 항해시와 LNG Unloading시에 대해 전력조류해석(정특성 해석)으로 시스템 모델링의 타당성을 검증하였다. 아울러, LNG Unloading에 대한 Cargo Pump 기동시 시스템의 전압변동률 및 발전기의 주파수(속도)변화를 관찰하였으며, PID제어기로 구성된 발전기 Governor의 파라미터를 설계하기 위해 실제 항해시 발생할 수 있는 몇 가지 상황(발전기 및 추진전동기 Trip)의 과도안정도해석을 수행하였다. 따라서 전동기 기동해석 및 과도안정도해석(동특성 해석)으로 발전기 및 추진전동기의 전압안정성을 관찰하였다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.25 no.5
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• pp.709-718
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• 2021

As regulations on environmental pollution of ships have been strengthened, interest in smart ships such as electric propulsion ships equipped with hybrid power systems is increasing. Since batteries used in electric propulsion ships have a larger capacity than batteries used in vehicles, the price is high and maintenance is considered important. The ship's battery is manufactured as an integral type and is managed by the battery management system, and the maintenance and repair of the battery is performed through the replacement of the battery. we design and implement a battery module and a control algorithm using pre-cell for easy battery management. In addition, a controller is designed to transmit the data necessary for the electric propulsion ship power system control to the power control system. When a battery to which the corresponding spare-cell is applied is used, the stability of the ship and the battery system is increased, and it can have an advantage in terms of maintenance and repair.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2011.06a
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• pp.317-320
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• 2011

정보통신 기술의 발달과 환경오염 문제의 심각성에 대한 인식 때문에 근래에 선박에 새로운 개념이 도입되고 있다. 전전기 스마트선은 전기 추진체계를 포함한 선박 내 모든 전력계통 구성품의 관련 요소들을 선박의 목적과 특성에 맞게 운영 되어지는 신개념의 선박이다. 이 연구에서는 전전기선 체계통합 시스템에 대하여 설명할 것인데, 이는 선박의 추진 및 전력, 기관제어계통 등 전체 시스템에 대한 획득 및 수명주기 비용 절감을 위한 통합 관리 체계를 목적으로 한다. 전기추진체계를 이해하기 위해서는 선박 내에 모든 전력 구성품의 통합 적인 이해가 필요 하며, 이를 위해서 전력제어, 전력배전, 통합 최적화를 위한 개념에 대해서 정확히 이해하여야 한다. 이 연구에서는 체계통합기술의 전반적인 이해를 돕는 데에 있다.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.23 no.8
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• pp.923-929
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• 2019

The stability of the propulsion system is crucial for the autonomous vessel. Multiple power generation and propulsion systems should be provided for the stability of the propulsion system. High power generation capacity is calculated for stability, resulting in economical decline due to low load operation. To solve this problem, we need to optimize the power system. In this paper, an OPMS for electric propulsion ship is constructed. The OPMS consists of a hybrid power generation system, an energy storage system, and a control load system. The power generation system consists of a dual fuel engine, the energy storage system is a battery, and the control load system consists of the propulsion load, continuous load, intermittent load, cargo part load and deck machine load. The power system was constructed by modeling the characteristics of each system. For the experiment, a scenario based on ship operation was prepared and the stability and economical efficiency were compared with existing electric propulsion ships.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2015.10a
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• pp.127-129
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• 2015

극지해역 운항선박은 주 추진시스템 및 선박 장비들이 일반 상선과 다른 경우가 많다. 따라서 극지운항 선박의 기관사들은 각종 장비 및 시스템에 친숙해져야 할 필요가 있다. 이 연구에서는 교육 및 훈련을 통해 극지 운항 선박에 승선하는 기관사관의 자질 향상을 통해 극지운항 선박의 안전운항을 도모하는데 있다. 또한, 그러한 자질 향상을 위해 필요한 Ice Engineer 교육 프로그램 방안을 모색하였다.