• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1995.04a
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• pp.165-170
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• 1995

소음저감 설계기술은 제품의 경쟁력 향상을 위해 일반인이 쉽게 접근할 수 잇는 가전제품, 자동차, 항공기 분야 등에서 많은 연구가 수행되어 왔으며, 최근 소음환경 규제가 강화되고 대형기계의 설치 위치가 주거지역과 가까워지므로 산업용 기계설비의 소음제어에 대한 관심이 점차 증대되고 있다. 특히 디젤 엔진 발전기 세트를 이용해서 전원을 공급하는 산업용 기계에 있어서는 디젤 엔진과 발전기가 주소음원이며, 크게 기계적 소음, 공기 역학적 소음, 그리고 전자기 소음 등으로 분류된다. 본 연구는 이러한 소음을 발생시키는 엔진(Engine), 발전기(Generator), 방열팬(Radiator Fan) 등의 성능을 개선시켜 소음을 감소시키는 것이 아니라, 외부 덮개(Canopy)에 흡음재를 부착하여 소음저감 방법을 채택했다. 연구대상으로서는 항만에서 컨테이너(Container)를 운송하는 이동용 크레인(Transfer Crane)의 엔진 발전기 세트(set)로서, 각 구성품(엔진, 발전기, 방열 팬)의 음향 덮개의 내부구조를 설계하였다. 그리고 덮개 내부 온도를 일정하게 유지시키기 위하여 엔진에서 방사하는 방열공기와 내부로 흡입되는 냉각공기의 열유동장 해석도 병행하였다.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.04a
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• pp.381-385
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• 2014

This paper investigates the magneto-rheological(MR) mount for the marine diesel-generator(D/G) sets. Sometimes, significant vibrations over the allowable limit are observed on the D/G sets due to their huge excitation forces. Because the severe vibration can lead to structural damages to the D/G sets, it should be reduced below the limit. Although passive mounts with rubber isolators are usually used, the vibration reduction performance is not always sufficient. In addition, expecting that the vibration levels required by customers will get more severe, vibration reduction devices need to be developed. To the aim, the flow mode type of MR mount has been designed. Especially, the annular-radial configuration was adopted to enhance the damping force within the restricted space. The geometry of the mount has been optimized to obtain the required damping force and the magnetic field analysis has been carried out using ANSYS APDL. To verify the performance of the developed MR mount, an excitation test was conducted. In addition, they were applied to a medium-speed diesel generator and it was verified that about 40% of vibration reduction was yielded.

• Proceedings of the Korean Society of Marine Engineers Conference
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• 2006.06a
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• pp.39-40
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• 2006

Diesel power plant(DPP) with the medium speed diesel engine is operated under the very severe condition in aspect of load and operating time as compared with the marine diesel generator set. So, minimized vibration level have to be insured for the more stable operation of engine and generator. The vibration of generator set mainly comes from the resonance between the rigid modes by resilient mount or distortion modes by structural stiffness and the excitation forces of engine. Then, avoidance of resonance with structural modification is generally well known. In this paper, the first order vibration in non-resonance range and local vibration modes were investigated by impact test, response/ODS(operational deflection shape) measurement and 3D finite element analysis for the additional reduction of vibration. The proposed countermeasures were actually applied and their final effects were verified through the in-situ measurement.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2014.10a
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• pp.294-297
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• 2014

A Shipboard power system consists of three or four diesel generator sets connected to a grid. In case of dual fuel diesel generator sets employed LNG ship as a prime mover, large amounts of electricity are required for electric propulsion, auxiliary machinery and accommodation facilities. The electrical connection between generators through a network, torsional vibration can lead power swings. In this paper, the influence on the network by the torsional vibration of diesel generator sets in grid operation were studied. The torsional vibration characteristics were investigated and analyzed through theoretical analysis and the vibration measurement and the results were presented.

• Proceedings of the KIPE Conference
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• 2010.07a
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• pp.560-562
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• 2010

본 연구의 목적은 농형 유도 발전기를 이용한 가변속 독립 운전형 풍력 발전 시스템의 최대 전력 추종 제어기법을 제안한다. 제안된 기법은 M-G 세트로 구성하여 풍력터빈의 역할을 하는 터빈 시뮬레이터를 직류전동기의 토크제어를 이용하여 구현하였다. 농형 유도발전기는 벡터제어를 기본으로 간접 벡터제어를 위하여 유도발전기를 좌표 변환하여 모델링하고 이것을 기초로 제어알고리즘을 도출하였다.

• Journal of the Korean Society of Propulsion Engineers
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• v.25 no.1
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• pp.68-76
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• 2021

The series hybrid system targeted in this study uses a reciprocating engine, a generator, and a battery as a main power source for the unmanned aerial vehicle. The generator is directly connected to the drive shaft of the reciprocating engine, and the operating characteristics of the reciprocating engine-generator set were confirmed through ground integration tests. In this study, based on the test results, a control logic is proposed an efficient use of the reciprocating engine-generator power and battery power. Also, the power variations of the reciprocating engine-generator and battery according to the logic were verified through simulation. As a result, it was confirmed that the engine-generator power supplied the power required for propulsion along with the battery power by the proposed control logic.

• Journal of the Korea Society for Simulation
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• v.32 no.3
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• pp.33-41
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• 2023

As carbon-free has been getting interest, renewable energy sources have been increasing. However, renewable energy is intermittent and variable so it is difficult to predict the produced electrical energy from a renewable energy source. In this study, digital-twin concept is applied to solve difficulties in predicting electrical energy from a renewable energy source. Considering that rotation of wind turbine has high correlation with produced electrical energy, a model which simulates rotation in the drivetrain of a wind turbine is developed. The base of a drivetrain simulation model is set with well-known state equation in mechanical engineering, which simulates the rotating system. Simulation based machine learning is conducted to get unknown parameters which are not provided by manufacturer. The simulation is repeated and parameters in simulation model are corrected after each simulation by optimization algorithm. The trained simulation model is validated with 27 real wind turbine operation data set. The simulation model shows 4.41% error in average compared to real wind turbine operation data set. Finally, it is assessed that the drivetrain simulation model represents the real wind turbine drivetrain system well. It is expected that wind-energy-prediction accuracy would be improved as wind turbine digital twin including the developed drivetrain simulation model is applied.

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.233-234
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• 2016

본 논문에서는 소형 어선의 전기 시스템을 DC 마이크로그리드의 관점에서 설계하고, 선박의 동력원인 엔진-발전기를 가변속 제어함으로써 선박 전력 계통의 효율을 개선하고자 한다. 선박 전력 계통은 물리적으로 육지 계통과 분리된 마이크로그리드의 형태를 갖추고 있다. 때문에 소형 기계 추진 어선의 경우, 추진을 위한 엔진뿐만 아니라 추가적으로 선내 전력을 공급하기 위한 엔진-발전기를 갖출 필요가 있다. 이에 반해 전기 추진 어선은 하나의 엔진-발전기 세트로 추진과 선내 전력 공급이 모두 가능하다. 하지만 어선이 정지 상태에서 조업을 할 때에 전력 부하량이 작기 때문에 엔진의 저부하 운전 문제가 발생한다. 본 논문에서는 이를 해결하기 위하여, DC마이크로그리드를 어선에 적용하여 엔진 가변속을 적용하고자 한다. 통상적으로 20% 내외의 부하율로 운용되는 엔진에 가변속 제어를 적용하면 20% 이상의 연비 개선 효과를 기대할 수 있다. 이러한 DC마이크로그리드 어선의 연비 개선 효과를 항해와 조업으로 구분하여 시뮬레이션을 통해 예측하였다.

• New & Renewable Energy
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• v.10 no.3
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• pp.31-38
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• 2014

The importance of energy is growing according to the energy shortage and environmental concerns. Accordingly, in order to solve the problems about the use of fossil fuel, a renewable energy sources are needed. Global renewable energy power industry's position in the renewable energy market becomes important and new technology development is also essential. MG set composed by the induction motor and permanent magnet synchronous generator for simulating a renewable energy source is based on a suitable experiment equipment. The torque generated by applying a voltage to the induction motor in MG set is used as an input of the permanent magnet synchronous generator. In Psim simulation, the characteristics of the induction motor model was formulated and the output torque characteristics of the motor was controlled using the induction motor side inverter, In this paper, the comparison analysis between Psim simulation and the output characteristics of the MG set is performed in order to identify a renewable energy power system more accurately.

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.1
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• pp.73-80
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• 2004

In this paper, a maximum output power control of stand-alone cage-type induction generator systems for wind power generation is proposed. The induction generator is operated in a vector-controlled mode, which is excited with d-axis current and of which torque is controlled with q-axis current. The generator speed is controlled by this torque, along which speed the generator produces the maximum output power. The generated power charges the battery bank for energy storage through an ac/dc PWM converter. The proposed scheme has been verified for the wind turbine simulator system which consists of M-G set.