• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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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.

• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.2
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• pp.114-120
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• 2012

Recently, integrated electric propulsion system has been vigorously adopted into naval vessels. To enhance effectiveness and efficiency of power management in these propulsion systems, this paper investigates necessity of energy storage devices and their operation strategies. By introducing the energy storage devices, engine can operate at higher efficiency point and accordingly costs for fuel and maintenance are significantly reduced. In addition, transient performance can also be improved with support of the devices and it leads to stable operation of shipboard power bus. To validate the proposal of this paper, computer simulation has been conducted with real load data of existing electric propulsion system.

• 한국전산유체공학회:학술대회논문집
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• 2003.10a
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• pp.248-250
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• 2003

Thermal analysis is performed to protect the propulsion system of low-earth-orbit earth observation satellite from unwanted thermal disaster like propellant freezing. To implement thermal design adequately, heater powers for the propulsion system estimated through the thermal analysis are decided. Based on those values anticipated herein, the average power for propulsion system becomes 22.02 watts when the only one redundant catalyst bed heater is turned on. When for the preparation of thruster firing, 25.93 watts of the average power is required. All heaters selected for propulsion components operate to prevent propellant freezing meeting the thermal requirements for the propulsion system with the worst-case average voltage, i.e. 25 volts.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2010.11a
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• pp.816-819
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• 2010

A study on the required propulsion powers at the EAV2 electric propulsion vehicle using power system such as solar cell, fuel cell and secondary cell is conducted, through which the scenario about available supply power is discussed at the optimum propulsion system weight on the specified flight envelope. In the result, it is noticed that propulsion system weight is 7.06kg and fuelcell 500W and secondary cell 100W are available to flight for glider-type electric vehicle with 6m length, 0.35m width.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2007.11a
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• pp.13-16
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• 2007

Fuel cell was used as a propulsion system for unmanned aerial vehicles (UAV) in the present study. Fuel cell propulsion system are an ideal alternative power source with high energy density for high-endurance UAV. Fuel cell power system provides UAV up to five times the energy densiη of existing batteries. Sodium borohydride, stored in liquid state, was selected as a hydrogen source. Hydrogen generation system consists of catalytic reactor, pump, fuel cartridge, and separator. Hybrid power management system (PMS) between fuel cell and lithium-polymer ba야ery was developed. Motor, pump, and fans， operated on battery power controlled by feedback signals of fuel cell system. Battery was recharged by surpuls powr of fuel cell.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.5
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• pp.777-781
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• 2012

In this paper, an electrical power simulation program was developed to predict the energy consumption of the electrical railway propulsion system, which considered the actual operating conditions of the electric railway vehicles. The developed program was designed to predictable the energy consumption during a virtual driving in the actual route of the virtual railway vehicles equipped with a propulsion system consisting of power conversion equipments and traction motors. In addition, the accuracy verification of the electrical power simulation program for a propulsion system was performed by using a real power consumption data, which was measured during the driving of the railway vehicles in the Gyeongui Line. In conclusion, the electrical power simulation program for a propulsion system was validated throughout a comparative investigation between the simulated values and the experimental values and the energy consumption characteristics of electric railway vehicles on the existing route or the new route will be possible to predict throughout the virtual simulation considering the driving conditions of the electric railway vehicles.

• Journal of the Korea Institute of Military Science and Technology
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• v.24 no.4
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• pp.457-466
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• 2021

This paper describes the design of model-based fault diagnosis software to apply to the propulsion system in tracked amphibious assault vehicle which consists of an engine, a transmission, a cooling system, and two waterjets. This software includes specific functions to detect the failures regarding sensor malfunctions, mechanical malfunctions, control errors, and communication errors. This software generates the proper malfunction codes which are classified as the warning and caution. In order to validate the fault diagnosis software, the manual and automatic test are performed using the test program with 32 test cases. Test results show that the designed fault diagnosis software is reliable and effective for applying to the propulsion system.

• Journal of the Korean Society of Propulsion Engineers
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• v.26 no.3
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• pp.1-9
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• 2022

The aircraft targeted in this study is a vertical take-off and landing aircraft with 4 to 5 passengers, and the propulsion system for the aircraft is a distributed hybrid propulsion system that uses a gas turbine engine and a battery pack as the main power source to supply the power required by multiple motors. In this study, a design/analysis platform for a hybrid propulsion system was developed using the MATLAB/Simulink program based on the preliminary design results. Through simulation analysis, the output characteristics and operating range of each power source according to the mission profile were confirmed, and through this, the feasibility of the preliminary design result was confirmed.

• Journal of Power Electronics
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• v.15 no.1
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• pp.146-159
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• 2015

Since the power capacity needed for the propulsion of large ships is very large, a multiphase AC induction propulsion mode is generally adopted to meet the higher requirements of reliability, redundancy and maintainability. This paper gives a detailed description of the development of a 20MW fifteen-phase PWM driver for advanced fifteen-phase propulsion induction motors with a special third-harmonic injection in terms of the main circuit hardware, control system design, experiments, etc. The adoption of the modular design method for the main circuit hardware design can make the enclosed mechanical structure simple and maintainable. It can also avoid the larger switch stresses caused by the multiple turn on of the IGBTs in conventional large-capacity converter systems. The use of the distributed controller design method based on a high-speed fiber-optic ring net for the control system can overcome such disadvantages as the poor reliability and long maintenance times arising from the conventional centralized controller which is designed according to point-to-point communication. Finally, the performance of the 20MW PWM driver is verified by experimentation on a new fifteen-phase induction propulsion motor.

• Journal of Power System Engineering
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• v.14 no.1
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• pp.27-33
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• 2010

We investigate some operation characteristics and energy efficiency of the BLDC motor system driven by different two types power conversion method depends on same battery source for applying to electrical motor propulsion system of a small ship. Also, we suggest an estimation manner of operating performances such as total running distance and operating speed of ships from basic discharge voltage characteristics of batteries. Through some experiments, direct power conversion was better than indirect method on the view point of energy efficiency and the voltage discharge characteristics could be used as important design factor for estimating operating performances of small ships driven by electrical motors.