• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.796_797
• /
• 2009

1kW급 저소음 수직형 풍력발전기용 동기발전기 설계에 대해 설명한다. 낮은 풍량에 유리한 수직형 블레이드 특성에 맞춰 발전기는 코깅 토크가 낮아야 하며, 고효율화를 위해 다극형 설계가 유리하다. 현제 국내 수직형 풍력에 적합한 발전기가 대부분이며 수직형 풍력발전기에 적합한 낮은 코깅 토크의 발전기는 일반화 되어있지 않다. 본 논문에서는 동기발전기 최적 설계를 통해 코깅토크를 최소화 시켰고, 다극형 형태를 통해 낮은 풍량에서 고효율 출력을 만들어낼 수 있도록 200rpm에서 역기전력 96V, 1kw의 정격출력을 가지도록 설계 하였다. 수직축형태의 블레이드에 구조에 맞춰 축계통형 발전기 구조를 가지고 있고, 유한요소해석법을 이용 회전자, 고정자, 권선법, 영구자석 등의 구조를 최적화 시켰다.

• Proceedings of the KIEE Conference
• /
• 2009.07a
• /
• pp.1625_1626
• /
• 2009

최근 세라믹 메탈할라이드 램프의 사용이 증가함에 따라 고연색성, 장수명에 대한 기대치가 높아지고 있다. 이런 추세에 의하여 현재 정격수명이 15,000 ~ 20,000시간의 세라믹 메탈할라이드 램프가 개발되고 있으며 신뢰성에 대한 문제 또한 부각되고 있는 실정이다. 본 논문에서는 이러한 세라믹 메탈할라이드 램프의 수명 특성을 알아보기 위하여 "신뢰성기준 RS C 0085"를 바탕으로 램프를 20분 점등후 20분 소등을 한 주기로 하여 1,200회를 반복한 후 광학적 특성 및 전기적 특성을 측정하여 실험 전 초기 특성과 비교 분석하였다. 광학적 특성으로 광속과 효율은 3.1 [%] 감소, 연색성은 2.3 [%] 감소, 색온도 변화를 가져왔다. 전기적 특성으로는 램프 열화로 인한 내부저항의 변화로 인해 전압이 1.4 [V] 증가, 전류가 0.02 [A] 감소하였다.

• Proceedings of the KIEE Conference
• /
• 2007.04c
• /
• pp.231-233
• /
• 2007

본 논문은 신 발전방식 중 하나인 용융탄산염형 연료전지(Molten Carbonate Fuel Cell, 이하 MCFC) 발전시스템에서 생성된 전력을 계통에 안정적으로 변환, 주입하기 위한 계통연계형 전력변환기를 설계, 제작하고 성능 시험을 수행한 결과이다. 250kW급 MCFC 시스템의 정격 사양 및 스택의 운전 형태를 기반으로 250kW급 전력변환기 구조 및 단위기기를 설계하였고 전력변환기는 크게 DC/DC 컨버터부와 DC/AC 인버터부로 구성된다. 본 논문은 MCFC 발전 시스템에 적용되는 전력변환기(Power Conditioning System, 이하 PCS)를 제작하고 성능을 확인하는데 목적이 있다.

• Journal of Advanced Marine Engineering and Technology
• /
• v.37 no.1
• /
• pp.78-84
• /
• 2013

The objective of this paper is to develop 360 W class wind turbine tree using a helical type wind turbine. The performance of 100 W class helical wind turbine which finished the conceptual design has been forecast through the CFD analysis. After performed the analysis of one wind turbine performance, four wind turbine have been installed at the structure of a tree type and then the change of a output data has been verified through the CFD analysis. In this study, the CFD results of a helical wind turbine tree have been shown by a velocity and pressure distribution. The result could obtain more than rated power 360 W through the CFD analysis.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.1
• /
• pp.59-65
• /
• 2011

The aerodynamic power and torque of wind turbines are extremely nonlinear. Therefore, the overall dynamic behavior of a wind turbine exhibits nonlinear characteristics that are dependent on the magnitude of the wind speed. The nonlinear aerodynamic characteristics of the wind turbine also affect the characteristics of the control system of the wind turbine. Therefore, the analysis of the nonlinear aerodynamic characteristics of wind turbine is essential in designing the wind-turbine controller. In this study, the nonlinear aerodynamic characteristics and the effects of these characteristics on the closed-loop pitch system with PI controller for an 1-mass model of the wind turbine are investigated above rated power.

• Journal of the Korean Society for Precision Engineering
• /
• v.20 no.7
• /
• pp.105-113
• /
• 2003

This paper describes the development of a 6-axis robot's finger force/moment sensor, which measures forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously, for stably grasping an unknown object. In order to safely grasp an unknown object using the robot's gripper, it should measure the force in the gripping direction and the force in the gravity direction, and perform the force control using the measured forces. Thus, the robot's gripper should be composed of 6-axis robot's finger force/moment sensor that can measure forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously. In this paper, the 6-axis robot's finger force/moment sensor for measuring forces Fx, Fy, Fz, and moments Mx, My, Mz simultaneously was newly modeled using several parallel-plate beams, designed, and fabricated. The characteristic test of made sensor was performed. and the result shows that interference errors of the developed sensor are less than 3%. Also, Robot's gripper with the 6-axis robot's finger force/moment sensor for the characteristic test of force control was manufactured, and the characteristic test for grasping an unknown object was performed using it. The fabricated gripper could grasp an unknown object stably. Thus, the developed 6-axis robot's finger force/moment sensor may be used for robot's gripper.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.21 no.8
• /
• pp.44-53
• /
• 2007

In this paper, the Sliding Mode Controller is applied to reduce the starting current of the single phase induction motor. The input voltage to the single phase induction motor is controlled so that the starting current of the motor may be maintained within the rating value and the velocity is also controlled, by adjusting the switching function of the Sliding Mode Controller. The switching of sliding control made appropriately with regard to velocity error signal and acceleration signal. It is shown that the starting characteristics of the single phase induction motor(SPIM) can be greatly enhanced through the sliding control of single phase induction motor.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.22 no.2
• /
• pp.120-127
• /
• 2008

This paper proposes a new vector control method using two rectangular hall sensors instead of using the expensive encoder and resolver. The proposed method estimates the speed and motor position by using the quadruple of two hall sensors signals instead of encoder signal. The proposed new speed estimation method is stable under the rated speed range. This algorithm will be able to moderate prices of the whole system and apply to the condition unfitted with encoder and resolver.

• The Transactions of the Korean Institute of Power Electronics
• /
• v.7 no.4
• /
• pp.359-365
• /
• 2002

Three-phase four-wire electrical distribution systems have been widely employed in manufacturing plants, commercial and residential buildings. Due to the nonlinear loads, the neutral conductor carries excessive harmonic currents resulting in wiring failure of the neutral conductor, overloading of the distribution transformer and a voltage drop between the neutral and the ground. This paper proposes a reduced rating active power filter to suppress neutral current harmonics in three-phase four-wire electrical distribution systems. The proposed system is simple in control and the VA rating of the inverter could be significantly reduced since only the fundamental current due to unbalanced loading flows through the inverter switch. The experimental results on a prototype validate the proposed control approach.

• Journal of the Korean Society for Railway
• /
• v.10 no.2 s.39
• /
• pp.112-116
• /
• 2007

In this paper, we proposed a selection and application recommendations of ZnO arresters for DC electric traction vehicles. To decide the Continuous Operating Voltage($U_C$), the Rated Voltage($U_r$), and the Nominal Discharge Current(In), we measured and analyzed system voltages and surge currents flowing the arrester installed on a DC electric traction vehicle under running state. System voltages measured up to 1,800 V in 1,500 V-system, and surge currents were recorded up to 3 times per a running-service-route and their magnitudes were ranges of $150A{\sim}2kA$. From these results and a standard EN50163, we could proposed $U_C$, $U_r$, and In available for the 1,500 VDC electric traction vehicles.