• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.5
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• pp.1049-1059
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• 2017

After patrol corvett Cheonan was hit and sank on duty, the Republic of Korea Navy has tried to install hybrid propulsion system on naval ship to reduce vibration and noise problems during navigation. The hybrid propulsion system has advantage that propulsion motor can be propelled in low speed operation of the vessel. This can be a better quietness than a mechanical propulsion system which consists of a conventional internal combustion engines. And more economical operation is possible by using a propulsion motor in a low speed operation where a fuel efficiency of the internal combustion engine is poor. In this paper, we set up virtual ship on the basis of a combat support ship in the Republic of Korea Navy, economically compared and analyzed fuel consumption between conventional and hybrid propulsion system. As a result, it was confirmed that the fuel efficiency of hybrid propulsion system which use electric motor had been relatively improved.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2003.10a
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• pp.122-125
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• 2003

For Lab-scale Hybrid Rocket's Ignition, It is needs of heat source to vaporize solid fuel. We used Nichrome wire which has a electric resistance for ignition. But Ignition system by using Nichrome wire is not only the disposable system, but also the system which has an affect on the Hybrid rocket's structures(nozzle throat diameter). The new Ignition system composed of Butane+propane gas' supply devices and spark plug. RPL(Rocket Propulsion Lab.) perform the hybrid rocket experiments over 50 times by using new ignition system. The fact that is possible to throttle the Thrust in hybrid rocket is confirmed.

• Proceedings of the KIEE Conference
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• 1997.11a
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• pp.642-645
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• 1997

This paper presents a propulsion control system for electric car to improve traction capability. The presented VVVF inverter was composed of as IGBT and the controller was full digitalized by using 32bit DSP. The improved PWM algorithms was adapted to improve traction characteristics. The system could be possible the higher reliablity, compact, light, low cost' and flexbility.

• Journal of Hydrogen and New Energy
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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 IKEEE
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• v.25 no.3
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• pp.556-564
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• 2021

This paper presents trends of safety improvement technologies for an electric propulsion system of eco-friendly ships. As an effort to reduce a green house effect, demands for eco-friendly ships have been increased. An energy storage system (ESS) is one of key systems in an eco-friendly ship and a lithium-ion battery generally used in an ESS system due to its high power density and efficiency. However, a lithium-ion battery is considered as one of reasons for ESS fire hazard. Since a fire extinguishing facility is especially limited in the ocean, safety issue in an eco-friendly ship is important. In this paper, recent safety improvement technologies for traction motors, ESS batteries and structures for eco-friendly ships are presented.

• Proceedings of the KSR Conference
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• 2005.05a
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• pp.220-224
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• 2005

EMU(Electric Multiple Unit) operated in local area is mostly consist of moving system on the rail and the traction motor drives the gear and wheel with the mechanical propulsion force. Most of countries are interested in Magnetic Levitation Vehicle for the transportation system on next generation and they have been studying about it continuously. Thus this paper is studied the Linear Induction Motor as the propulsion equipment of Magnetic Levitation Vehicle

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.226-232
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• 1998

In this pager, we present IGBT VVVF inverters as a 1C1M propulsion system for electric car. This inverters are composed of high power IGBT's and controlled by compact control units. The control unit performs full digital control by using 32bit DSP and microconteroller. By using CAN-bus, high speed network is constructed within tow control units. The stack is simplified and optimized by using plate bus and IGBT driver units of hybrid-type.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2012.06a
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• pp.224-224
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• 2012

• The Transactions of the Korean Institute of Power Electronics
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• v.21 no.5
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• pp.388-395
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• 2016

Electric vehicles (EV) and hybrid EVs (HEV) are designed and manufactured by GM, Toyota, Honda, and Hyundai motors. The propulsion system design process for EV requires integrating subsystem designs into an overall system model to maximize the performance of a given propulsion architecture. Therefore, high-power density and high-torque density are important attributes required for EV applications. To improve torque and power density, propulsion motors are designed for saturation during high-torque operation. The nonlinearity associated with core saturation is modeled by incorporating the cross-coupling inductances, which also behave nonlinearly. Furthermore, in EV environments, the battery is directly connected to the DC link, and the battery changes depending on the state of charge. It will be onerous if as many optimal current commands as different $V_{dc}$ were made. This paper presents the optimal current commands in the various operating condition and the current control technique in EV environments.

• Journal of Power Electronics
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• v.14 no.2
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• pp.402-412
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• 2014

This paper proposes a novel electric propulsion system for naval ships, which consists of Active Front End (AFE) converters directly connected to battery Energy Storage Modules (ESMs). Employing the proposed AFE converters with ESMs in the power systems of naval ships can enhance the reliability and quality of the electric power. Furthermore, the fuel-efficiency of the generator can be improved by a higher loading factor of the generator and its prime movers. The proposed AFE configuration does not require an additional dedicated DC/AC converter for the ESMs. Instead of that, the AFE converter itself can control the DC link voltage and the discharging and/or charging of the ESMs. A control scheme to achieve these control objectives is also presented in this paper. The overall power system, including the generators and electrical loads of a naval ship, is implemented by a small scaled Power Hardware-In-the-Loop (PHIL) simulator. Through this experimental setup, the proposed system configuration and the power control strategies are verified. It is shown that the fuel-efficiency and transient dynamics can be improved in the normal and contingency operation modes.