• 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 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.

• 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.

• 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 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 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.

• 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.

• 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 Propulsion Engineers Conference
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• 2011.11a
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• pp.544-547
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• 2011

This paper describes on hardware simulation of passive power control of propulsion system for electric propulsion aircraft of KARI. The propulsion system uses hybrid power system that is composed of solar cell, fuel cell and battery. The fuel cell is replaces by simulator due to its difficulty in handling while the other components are the same as that will be used on board. As the result, reliable power supply for propulsion is confirmed and each power source is well operated showing its characteristics.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2008.05a
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• pp.155-158
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• 2008

Development of Moon Explorer-1 (orbiter) is supposed to be commenced in 2017 and launched in 2020. In case of Moon Explorer-2 (lander), it would be slated to start in 2021 and launch in 2025. For this reason it is taken for granted to investigate a fundamental propulsion system for a Moon Explorer. In this paper conceptual feasibility and comparison studies are proposed for the propulsion system applicable to a Moon Explorer. Availability of monopropellant/bipropellant/electric propulsion system is compared and analysed as well with precedents overseas. As a result possible candidates for a Moon Explorer propulsion system are suggested.