• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.46 no.4
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• pp.503-508
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• 2010

Common LED (Light Emitting Diode) lamp has many advantages to compare with fluorescent lamp, long life and no pollution matter like the mercury. The LED lamp is a good light source especially for shipboard lighting because of its compact structure which prevents explosion and shock. Also, low maintenance cost is expected due to its longer life time in comparison with conventional lamps. The LED lamp, however, need some estimates that change of voltage and frequency, vibration, moisture on board to definite accommodation of the LED lamp to shipboard. The purpose of this study is to compare physical properties of a fluorescent lamp with one of the common LED lamp so as to analyze accommodation of common LED lamp on board. This study was carried out in two stages. First, temperature, humidity of illumination, voltage, electric current, frequency and electric power were measured by using experimental equipments. Second, a comparative analysis of consumption electric power, annual oil charge, annual CO2 emission and lamp life time, etc of the fluorescent lamp and common LED one was made. As a result of the study, the consumption electric power of fluorescent lamp was 50% higher than one of the common LED lamp. As a result of measuring life time, it was found that life time of common LED lamp was more about 3.5 fold than one of the fluorescent lamp. Considering these results, it's thought that common LED lamp is verified that energy saving is possible and using is possible as substitute for fluorescent lamp on board.

• Proceedings of the KIEE Conference
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• 2003.04a
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• pp.40-43
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• 2003

An electric propulsion system integrated with the ship service distribution system offers the naval architect considerable flexibility, and often the choice of a more affordable ship to acquire and operate as compared to a segregated mechanical drive option. United States of America navy announced in 2000 that they selected the electric propulsion system on next generation warship. Specially there is excellent advantages in superconductivity motors which can have higher efficiency, less vibration and noise, smaller dimensions compared with the conventional motors. The 5 MW HTS motor for warship test of electric propulsion was developed and tested. Also it was contracted between AMSC and United States of America navy to develop a 36.5 MW HTS motor in 3 years since March 3, 2003. This paper deals with the technical development tendency of HTS motors in foreign countries as well as in domestic, and it is focused on the application of HIS motors to the electrical propulsion system.

• The Transactions of the Korean Institute of Power Electronics
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• v.20 no.1
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• pp.45-50
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• 2015

The simulation model of All-Electric-Ship consists of electrical and mechanical systems. Running the total simulation requires considerable time and causes a lack of computer memory, because the two systems have different dynamic characteristics. Therefore, integrated simulation is practically impossible. This paper proposes the simplified model of electrical system to reduce simulation time significantly, compared to the detailed model. The validity of the proposed simplified model is verified by comparing detailed and simplified simulation results. Thus, the simplified models are applied to the integrated system. As a result, total system simulation can be implemented.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.7
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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.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.6
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• pp.946-951
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• 2009

An induction motor based on DTC(Direct Torque Control) is being increasingly used in various industrial applications. DTC offers faster torque response and better speed control with lesser hardware and processing costs in compared with other controlled drives. This study was to evaluate performance of DTC for induction motor of electric propulsion ship. The simulation results indicated good speed and torque response from the low to middle speed range. Also, DTC has advantages such as the independency on motor parameter.

• 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.

• Transactions of the Korean hydrogen and new energy society
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• v.35 no.2
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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.

• Journal of Advanced Marine Engineering and Technology
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• v.33 no.6
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• pp.880-885
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• 2009

The ships have a lot of electric machinery needed to supply electricity from the moment of launching coming out of dry dock to docking at jetty. Thus, the ships always have to use alternator and electric machinery that has low efficiency under the low load. Many government service ships like the MMU training ship have been spending lots of time at jetty rather than sailing at sea. These ships are operated under the condition of low load due to the operation of basic machinery at jetty and electric machineries are driven with the status of low efficiency. This paper would suggest the energy saving method for these ships. The investigation describes that shore connection is a great asset to these ships and that the flow rate control by adjusting revolution with the adoption of inverter is better than flow rate control by using throttle valve to save energy. The result is based on the investigation of cooling pump at MMU training ship.

• Journal of the Society of Naval Architects of Korea
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• v.60 no.3
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• pp.146-154
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• 2023

Efforts have been made to reduce the greenhouse gas emissions from ships by limiting the energy efficiency index, and net zero CO₂ emission was proposed recently. The most ideal measure to achieve zero emission ship is electrification, and fuel cells are considered as a practical power source of the electrified propulsion system. The electric efficiency in the electrochemical reaction of fuel cells can be achieved up to 60% practically. The remaining energy is converted to heat energy but most of them are dissipated by cooling. In the author's previous research, a hybrid propulsion system utilizing not only electricity but also heat was introduced by combining electric motor and steam turbine. In this article, long term efficiency is evaluated for the introduced hybrid propulsion system by considering a virtual 24,000 TEU class container carrier model. To reflect a more practical operating condition, the actual navigation data of a similar real ship in the real world were collected from automatic identification system data and applied. From the result, the overall efficiency of the hybrid propulsion system is expected to be higher than a conventional electric propulsion fuel cell ship by 30%.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.20 no.12
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• pp.2235-2242
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• 2016

The electric power system based on fuel cell is applied in various forms to the ship and offshore plants. In particular, a research on the hybrid power system of the fuel cell combined with battery in connection topology has been researched actively. Fuel cell-based hybrid ship has not been carried out research, it is not carried out research in the integrated monitoring system. In this paper, we developed an integrated monitoring system to increase the convenience and stability for the hybrid fuel-cell ship operator. Research into integrated monitoring system based on GUI (Graphic User Interface), in consideration of the stability of the user convenience and ship operations, and developed communication and hardwired signal with the main equipment of the ship, to see in realtime state of the ship. The collected ship operation data is stored and it can be seen after the ship operating.