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

• 한국정보통신학회논문지
• /
• 제21권7호
• /
• pp.1455-1463
• /
• 2017

세계경기가 저성장, 저소비, 높은 실업률, 고위험, 짧은 호황 긴 불황 등을 기록하고 있다. 이에 따라 해운경기가 하락하여 선박 유지비용의 절감이 불가피해지고 있다. 이를 위해 그린 선박, 에코 선박, 스마트 선박과 같은 선박의 에너지를 절감하기 위한 연구가 활발히 진행 중에 있다. 친환경 선박에서 배터리를 사용하는 전력관리시스템은 중요한 연구분야 중 하나이다. 본 논문에서는 발전기만을 사용하는 일반적인 선박의 전력관리시스템의 중부하 제어를 분석하고 배터리 연계형 전력관리시스템에서 중부하를 제어하는 알고리즘을 연구하였다. 이를 위해 배터리 연계형 전력관리시스템의 구성을 제안하고 제안된 시스템을 기반으로 배터리 연계형 전력 시뮬레이터를 구성하였다. 구성된 시뮬레이터를 통해 배터리 연계형 전력관리시스템에서 중부하 제어에 따른 배터리의 동작을 정의하고 이를 확인하였다.

• Journal of information and communication convergence engineering
• /
• 제14권2호
• /
• pp.122-128
• /
• 2016

In the future, hybrid power management systems using fuel cells (FCs) and batteries will be used as the driving power systems of ships. These systems consist of an FC, a converter, an inverter, and a battery. In general, an FC provides steady-state energy; a battery provides the dynamic energy in the start state of a ship for enabling a smooth operation, and provides or absorbs the peak or dynamic power when the load varies and the FC cannot respond immediately. The FC voltage range is very wide and depends on the load; Therefore, the FC cannot directly connect to the inverter. In this paper, we propose a power management strategy and design process involving a unidirectional converter, a bidirectional converter, and an inverter, considering the ship's operating conditions and the power conditions of the FC and the battery. The presented experimental results were verified through a simulation.

• 한국항해항만학회지
• /
• 제44권5호
• /
• pp.423-429
• /
• 2020

A ship's automatic steering system is the basis for addressing control difficulties related to course-changing and course-keeping during navigation through heading angle control, and is a link in realizing unmanned and autonomous ships. This study proposes a robust RCGA-based linear active disturbance rejection controller (LADRC) design method considering environmental disturbances, measurement noise, and model uncertainties in designing a ship heading controller for use when the ship is sailing. The LADRC consisted of a transient profile, a linear extended state observer, and a PD controller. The control gains in the LADRC with the linear extended state observer were adjusted by RCGAs to minimize the integral of the time-weighted absolute error (ITAE), which is an evaluation function of the control system. The proposed method was applied to ship heading control, and its effectiveness was validated by comparing the propulsive energy loss between the proposed method and a conventional linear PD controller. The simulation results showed that the proposed method had the advantages of lower propulsive energy loss, more robustness, and higher tracking precision than the conventional linear PD controller.

• 한국해양공학회지
• /
• 제33권5호
• /
• pp.447-453
• /
• 2019

Recently, environmental regulations have been strengthened for SOX, NOX, and CO2, which are ship exhaust gases. In addition, according to the 4th Industrial Revolution, research on autonomous ship technology has become active and interest in electric propulsion systems is increasing. This paper analyzes the power load characteristics of an electric propulsion ship, which is the basic technology for an autonomous ship, in terms of energy management. For the load analysis, data were collected for a 6,800 TEU container ship with a mechanical propulsion system, and the propulsion load was converted to an electric power load and clustered according to the characteristics using a SOM (Self-Organizing Map). As a result of the load analysis, it was confirmed that the load characteristics of the ship could be explained by the operation mode of the ship.

• 신재생에너지
• /
• 제9권4호
• /
• pp.3-12
• /
• 2013

This paper proposes the hybrid fuel cell system that can solve disadvantages of existing fuel cell system and ensure high reliability and high stability. The system consists of PEM fuel cell, Ni-MH battery and power management system. In this system, when the power provided from the fuel cell is higher than the load power, the extra energy may be used to charge the Ni-MH battery. When the fuel cell can not provide enough energy to the load, the shortage of energy will be supplied by the Ni-MH battery. Experimental results show that the output voltage is regulated well during load variations. Also, high system efficiency is achieved.

• International Journal of Naval Architecture and Ocean Engineering
• /
• 제12권1호
• /
• pp.440-454
• /
• 2020

To prevent pollution from ships, the Energy Efficiency Design Index (EEDI) is a mandatory guideline for all new ships. The Ship Energy Efficiency Management Plan (SEEMP) has also been applied by MARPOL to all existing ships. SEEMP provides the Energy Efficiency Operational Indicator (EEOI) for monitoring the operational efficiency of a ship. By monitoring the EEOI, the shipowner or operator can establish strategic plans, such as routing, hull cleaning, decommissioning, new building, etc. The key parameter in calculating EEOI is Fuel Oil Consumption (FOC). It can be measured on board while a ship is operating. This means that only the shipowner or operator can calculate the EEOI of their own ships. If the EEOI can be calculated without the actual FOC, however, then the other stakeholders, such as the shipbuilding company and Class, or others who don't have the measured FOC, can check how efficiently their ships are operating compared to other ships. In this study, we propose a method to estimate the EEOI without requiring the actual FOC. The Automatic Identification System (AIS) data, ship static data, and environment data that can be publicly obtained are used to calculate the EEOI. Since the public data are of large capacity, big data technologies, specifically Hadoop and Spark, are used. We verify the proposed method using actual data, and the result shows that the proposed method can estimate EEOI from public data without actual FOC.

• 한국정보통신학회논문지
• /
• 제23권8호
• /
• pp.923-929
• /
• 2019

자율운항선박의 기반은 추진시스템의 안정성이 중요하며, 추진체계의 안정성을 위하여 다중 발전 체계 및 추진체계를 갖추어야한다. 기존 선박에서는 안정성을 위하여 높은 발전 용량을 산정하며, 그 결과 저부하 운전으로 인한 경제성 하락을 야기한다. 이를 해결하기 위해서는 전력체계의 최적화를 통하여 발전 체계의 경량화와 효율의 증가가 필요하다. 본 논문에서는 전기추진선박용 OPMS(Optimization Power Management System)를 구축한다. OPMS는 하이브리드형 발전시스템, 에너지저장시스템, 부하제어시스템으로 구성된다. 발전시스템은 이중연료엔진, 에너지저장시스템은 배터리, 부하제어시스템은 추진 부하, 상용 부하, 불규칙 부하, 화물 기기 관련 부하, 갑판 부하로 구성된다. 각 시스템별 기기들의 특성에 대하여 모델링하여 전력체계를 구축하였다. 실험을 위하여 선박 운용에 따른 시나리오를 작성하고 안정성 및 경제성을 기존의 전기추진선박과 비교하였다. 실험의 결과 발전기의 비교적 적은 시간 투입으로 같은 전력량을 공급함으로써 선박의 LNG 1.3%, Main Fuel 0.3%, Pilot Fuel 35.1%의 연료소모량 감소를 통하여 경제성 및 안정성을 확인하였다.

• Journal of Advanced Marine Engineering and Technology
• /
• 제34권4호
• /
• pp.500-507
• /
• 2010

해운산업은 지구온난화와 관련하여 그린하우스가스(GHG)을 줄이기 위한 헌신적인 노력을 하여왔다. 2009년도 국제해사기구(IMO)의 GHG 연구팀에 의하면 해운분야에서 배출되는 GHG 중 가장 영향력이 큰 이산화탄소는 전체 배출량의 3.3%이며, 연간 10억톤을 초과하고 있다. 따라서 이를 줄이기 위한 수단으로 IMO에서는 2005년 에너지효율 운전지표(EEOI)와 2008년 에너지 효율 설계 지수(EEDI)를 차례로 제안하여 현재 규정 작업 중에 있다. 최근에는 선박의 선박에너지효율관리계획(SEEMP)을 제안하고 있고, 선박에서 배출되는 GHG의 모니터링 및 관리가 핫이슈로 떠오르고 있다. 본 연구에서는 선박에서 EEDI와 EEOI를 검증하고 에너지 사용을 체계적으로 관리하기 위한 에너지 효율 설계지수 / 에너지 효율 운전지표 모니터링 시스템(EDiMS)을 개발하여 선박에 활용하고자 한다. 이 모니터링 시스템의 개발은 종전 목포해양대학교 동역학연구실에서 기 개발한 상태모니터링 시스템의 일종인 EVAMOS($\underline{E}$ngine $\underline{V}$ibration and $\underline{A}$nalysis $\underline{MO}$nitoring $\underline{S}$ystem)을 기초로 하여 개발시간을 최대로 단축하였다. 주기관의 공장 시운전시 측정한 연료소모량, 질소산화물(NOx), 황산화물(SOx), 입자상물질(PM)의 자료를 이용하여 선박의 운항 시 동력과 선속을 동시에 모니터링하여 이들 성분의 자료를 측정저장함으로써 선박마다 GHG에 대한 정확한 인벤토리를 구할 수 있도록 하였다. 그리고 이 자료는 IMO의 가이드라인을 만족하는지 확인할 수 있을 뿐 아니라 장기적으로는 GHG를 줄이기 위한 노력의 일환으로 선박관리와 SEEMP 등에 유용한 도구로 사용할 수 있도록 하였다.

• 대한조선학회논문집
• /
• 제52권2호
• /
• pp.110-118
• /
• 2015

Weather routing method is one of the best practices of SEEMP (Ship Energy Efficiency Management Plan) for fuel-efficient operation of ship. KR is carrying out a basic research for development of the weather routing algorithm and making a monitoring system by FOC (Fuel Oil Consumption) analysis compared to the reference, which is the great circle route. The added resistances applied global sea/weather data can be calculated using ship data, and the results can be corrected to ship motions. The global sea/weather data such as significant wave height, ocean current and wind data can be used to calculate the added resistances. The reference route in a usual navigation is the great circle route, which is the shortest distance route. The global sea/weather data can be divided into grids, and the nearest grid data from a ship's position can be used to apply a ocean going vessel's sea conditions. Powell method is used as an optimized routing technique to minimize FOC considered sea/weather conditions, and FOC result can be compared with the great circle route result.