• Journal of Aerospace System Engineering
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• v.16 no.3
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• pp.42-51
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• 2022

An eVTOL aircraft, which is required to operate with low pollution/low noise in urban environments, mostly use battery-powered electric propulsion systems as power sources, not traditional propulsion systems such as reciprocating or turbine engines. Accordingly, certification preparation for the electric propulsion system and securing the safety of the electric propulsion system, are important issues. In the U.S., special technical standards equivalent to FAR Part 33 were issued to certify electric engines, and in Europe, various special conditions were established to certify electric propulsion systems. Thus, in Korea, the technical standards for the electric propulsion system for eVTOL aircraft must also be prepared in line with the U.S. and Europe. In this paper, SC E-19, the technical standard of the electric/hybrid propulsion system (EHPS) in special conditions, was analyzed. Additionally, securing the safety of the electric propulsion system of the aircraft are proposed, through the collaboration of SC E-19 technical standards with the existing aircraft safety evaluation procedure ARP 4761. Finally, through a case study of the Ehang 184 electric propulsion system, it has been confirmed that the proposed safety assurance method is applicable at the aircraft level.

• Journal of Aerospace System Engineering
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• v.16 no.5
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• pp.26-34
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• 2022

The propulsion system of geostationary orbiting satellites is typically used to raise the orbit into a transfer orbit, maintain the orbital position in the south/north, east/west direction in regular operation, and accumulate momentum in the south/north and east/west direction. Recently, when an electric propulsion system is used in a geostationary orbit satellite, the payload capacity can be increased by about 40% compared to a chemical propulsion system. However, despite these advantages, using an electric propulsion system has several limitations that should apply to all geostationary orbiting satellites. This paper discusses the operational constraints to consider when developing an indigenous geostationary satellite using a fully electric propulsion, radiation exposure, and control mechanism design due to unit displacement and floating ground-design. A high-voltage control unit for electric drives were analyzed.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.6
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• pp.53-59
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• 2021

The ROK Navy operates many war ships despite its short history. Various types of war ships, such as submarines, destroyers, frigates, corvette etc., use suitable propulsion systems for the operational requirements of each war ship. A hybrid propulsion system was introduced to change from the current mechanical propulsion system to an electric propulsion system according to the changing patterns of naval warfare, and it is expected that an integrated electric propulsion system will also be introduced. Therefore, this paper investigates the propulsion system of major ships operated by the Korean Navy, predicts the changes in future naval warfare, and proposes a propulsion system for future ships.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2005.06a
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• pp.1029-1034
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• 2005

함정의 추진시스템은 기계식에서 에너지 효율이 높고, 구성 장비의 수가 줄어들며 유지 보수 특성이 향상되는 전기식으로 연구 개발되어지고 있는 추세이다. 따라서 본 논문에서는 함정의 전기추진시스템의 장점과 현재 개발중인 전기추진 함정의 기술과 발전 경향을 분석 조사하였다.

• Journal of Navigation and Port Research
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• v.32 no.10
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• pp.765-770
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• 2008

This paper presents the power control for the hybrid electric propulsion system. In this paper, the hybrid propulsion system consists cf the generator and battery as power supply system in ship. The hybrid control system is designed with energy saving algorithm for decreasing the power consumption of power supply system. This paper suggests the method to increase efficiency of hybrid electric propulsion system by developing battery charging system. The performance of power control system is analyzed with the experiment equipment for hybrid propulsion system, and the results showed a good property.

• Journal of the Korean Society of Propulsion Engineers
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• v.14 no.6
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• pp.1-8
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• 2010

In this paper, we present some results of technical surveys, power analyses, and weight estimation on electric propulsion systems for 1-ton class Personal Air Vehicles(PAV) applications. When hybrid electric propulsion is adopted, its power performance using fuel cells and batteries in inferior to that of internal combustion engines. However, hybrid electric propulsion systems may replace IC engines when energy density and power density reach 0.75 kW$^*$hr/kg and 2.5 kW/kg, respectively.

• Proceedings of the KIPE Conference
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• 2019.07a
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• pp.392-393
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• 2019

본 논문에서는 전기 보트 추진을 위한 SPMSM(Surface mounted Permanent Magnet Synchronous Motor) 구동 시스템을 개발하였다. 전차원 폐루프 관측기를 이용하여 외란 토크 관측기를 구성하고, 관측된 외란 성분을 속도 제어기 출력에 보상하여 속도 제어 성능을 향상시켰다. 리튬이온 배터리, 인버터 및 1kW SPMSM으로 구성된 전기 보트 추진 시스템을 이용한 구동 실험을 통해 추진용 전동기의 속도 제어 특성을 확인하였다.

• 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 KIEE Conference
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• 2015.07a
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• pp.1607-1608
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• 2015

현대사회의 고속 고급 교통수단에 대한 요구에 부응하고, 고유가 및 온실가스 등 원유 기반의 교통 시스템의 문제를 해결하기 위해 교통 수단의 다양화 연구가 활발히 진행되고 있다. 석유문제가 심각한 상황으로 전개될 경우, 대륙과 대륙 그리고 국가와 국가 사이의 장거리 이동을 할 수 있는 교통수단은 전기로 추진되는 철도이다. 현재 대중화 되어있는 바퀴 식 철도차량은 초고속 운전 시 기하급수적으로 증가하는 소음, 공기저항 동력 전달의 한계, 레일의 마모라는 문제를 가지고 있으며 이러한 문제점을 가진 철도차량의 대안으로 선형 추진 시스템 연구가 진행 중이다[1] 국내에서는 LSM(Linear Synchronous motor)에 대한 연구가 활발히 진행되고 있으나 LPM 기반 철도 차량 추진시스템에 대한 연구는 이루어지지 않고 있다. 그러나 LSM 추진 시스템에 비하여 LPM 추진 시스템은 우수한 등판 능력, 광역범위의 주행 가능 영역, 경량화에 따른 높은 에너지 효율, 건설비 저감등 다양한 장점을 가지고 있으며 충분한 전략성을 가지고 있다.

• 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.