• 신재생에너지
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• 제6권4호
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• pp.41-49
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• 2010

Over the last decade, wind turbine industry has rapidly increased around world. These days many parts of the wind generators are induction generator. But it has some problems such as gearbox failure, rotor excitation and maintenance. Thus many manufacturers are considered permanent magnet synchronous generator named PMSG and direct drive. PMSG uses NdFeB magnet has many the advantage compare with induction generator. In this study, 3MW class outer rotor type PMSG for wind turbine is proposed. The generator features 2.6m stator outer radius, 1200mm stator length, 81 pole pairs, 14 rated rpm, 42kN/$m^2$ shear force density and 94.2% efficiency. Design and analysis generator using FEM program. Then calculate and derivate no load voltage, losses, conductor temperature. To reduce total harmonic distortion and cogging torque, the stator is applied the stator skewing. And to evaluate the designed generator, compare with other generators by active mass per rating torque and torque density.

• 대한기계학회논문집
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• 제15권2호
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• pp.488-496
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• 1991

Dynamic chanracterisitcs and control of a submerged working robot manipulator have been investigated for articulated type robot manipulator with three revoluted joints. A dynamic equation of the manipulator has been derived. The dynamic equation includes not only mass matrix, centrifugal and Coriolis terms and gravity terms but also added mass, buoyant force and drag force terms, which are important terms for underwater motion description. A series of simulations using computed torque method have been performed for the cases of straight and circular trajectory motion controls. The results of this study show that the dynamic characteristics of the submerged working robot manipulator are very different from that of the manipulator which works in air. The influences of added mass, buoyant force and drag force terms to the total required torques have been discussed as distribution ratios to the total required torques.

• KSTLE International Journal
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• 제2권1호
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• pp.75-79
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• 2001

This paper is a report on the parametric study of the friction characteristics on the direct acting type OHC valve train system. The numerical simulation was performed by using the IV-TAP. Dynamic analysis by using the lumped mass method was previously performed to define the acting load. The friction characteristics were analyzed by using the partial asperity contact model. The effects of operating conditions and major design parameters on the total driving torque were investigated. From the analytical prediction, it is found that valve spring stillness, surface roughness, and base circle radius are the main factors to reduce the frictional loss on the valve train system.

• 한국산학기술학회논문지
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• 제20권3호
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• pp.465-469
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• 2019

본 논문에서는 콘크리트 바이브레이터에 Slotless BLDC (Brush Less Direct Current) 모터를 적용하기 위해 BLDC 모터의 토크 및 역기전력 식을 기반으로 하여 설계를 한다. 모터의 길이와 직경의 사이즈가 주어져 있으므로 중요한 파라미터는 공극자속밀도이다. 자기회로의 간략화를 통하여 공극자속밀도를 계산 하였으며, 토크, 역기전력 및 공극자속밀도 식을 기반으로 기초설계를 진행하여 모터의 형상을 결정 하였다. 이후 모터의 고정자의 외경 및 내경, 스택 길이, 속도를 고정값으로 설정한 후 모터의 직경 및 두께를 변수로 지정하여 유한요소법을 이용한 시뮬레이션을 통해 상세설계를 진행하였으며, THD(Total Harmonic Distortion)값이 작으면서 목표 토크 값 이상의 형상을 설계 및 시뮬레이션을 진행하였다.

• 한국콘텐츠학회논문지
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• 제6권12호
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• pp.226-234
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• 2006

본 연구는 테이핑 요법이 슬관절의 등속성 기능 및 통증에 미치는 영향을 알아보기 위하여 슬관절 부위에 통증을 호소하는 $65{\sim}70$세 여성 노인 12명을 대상으로 슬건근, 대퇴사두근, 슬개골 부위에 폭 5cm의 테이프를 8주 동안 주당 3회씩 총 24회를 적용시킨 후 등속성 근 기능인 최대근력, 상대근력, 근 지구력(총 운동량), 근 지구력(운동피로도), 동측 근력 비율, 주관적 통증정도인 시각적 상사 척도와 구술적 평정 척도의 변화를 분석한 결과 다음과 같은 결론을 얻었다. 즉, 8주간의 테이핑 요법 후 최대근력, 상대근력, 근지구력(총 운동량), 동측근력비율은 각각 유의하게 증가하였고 (p<.05; p<.01), 근지구력(운동피로도) 및 시각적 상사 척도와 구술적 평정 척도 점수가 각각 유의하게 감소하였다(p<.05).

• 한국자동차공학회논문집
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• 제16권1호
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• pp.166-174
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• 2008

Recently, the automotive industry has been developing rapidly. With the progress parts of the automobile components need high quality and the reliability. Among them, braking unit is essential device, and acquire the reliability through the performance test of brake. This study was aimed to design the performance-test-bench to measure the drag torque which has effect on caliper in braking unit. In this progressive technology, it is vital importance to use hydraulic and pneumatic, and to combine test bench with instrumentation engineering technology. This system to construct the design of hydraulic and pneumatic circuit, interface technique between sensors and personal computer, data acquisition and display design, and integrated control are very important technology. Moreover, reliable data are obtained through vacuum system and hydraulic and pneumatic system by using of booster and brake master cylinder which are actually applied to automobile. Then, data signal detector sensors for speed, pressure and torque is attached on this system. Therefore, in this study, we designed a performance-test-bench by and we also made an total control system using personal computer which is more progressive and flexible method than existing PLC control.

• 전기학회논문지
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• 제65권6호
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• pp.987-994
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• 2016

In this paper, we present a comparative analysis of surface-mounted permanent magnet synchronous motors (SPMSM) and interior permanent magnet synchronous motors (IPMSM). First, we use 2D finite element analysis (FEA) to analyze models satisfying the same rated conditions according to the torque-speed curve characteristics, which are determined from the operating conditions. Next, we manufacture an SPMSM and IPMSM having good performances from an electromagnetic perspective based on analysis results, namely the cogging torque, torque ripple, and efficiency. We analyze both of the manufactured machines when they are connected back-to-back and when they are used as a motor and a generator, respectively. The motor is driven by a commercial inverter and the generator is connected to a three-phase resistance load bank. Finally, based on experimental results, which include the total harmonic distortion (THD) of the back electro-motive force (EMF), cogging torque, efficiency, and mass, we determine the motor that is most suitable under requirements.

• 한국통신학회논문지
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• 제16권11호
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• pp.1186-1193
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• 1991

본 논문에서는 신경회로망을 사용한 로보트 매니퓰레이터의 궤적 제어 방법을 제안하였다. 매니퓰레이터에 가해지는 토크는 신경회로망이 출력인 feedforward 토크와 보조제어기로 사용되는 비례 미분 제어기PD 제어기의 출력인 feedback 토크의 합이다. 제안된 전경 회로망은 다층 신경회로로서 시간 지연 요소를 가지며 PD 제어기의 오차 토크를 사용하여 매니퓰레이터 이동력학 모델을 학습한다. errror backpropagation(BP) 학습 신경회로 제어기를 사용해보므로서 매니퓰레이터 동특성에 대한 정보를 미리 필요로 하지 않으며, 연결 가중치 값에 그러한 정보가 저장된다. 확인될 신경회로망의 특성을 컴퓨터 시뮬레이션을 통하여 입증한다.

• Journal of Power Electronics
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• 제16권6호
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• pp.2162-2172
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• 2016

This paper presents a Direct Torque Control (DTC) strategy for the five-phase induction motor driven by a three-level five-phase inverter in order to improve the performance of the five-phase induction motor. In the proposed DTC technique, only 22 voltage vectors out of 243 available voltage vectors in a three-level five-phase inverter are selected and are divided in 10 sectors each with a width of $36^{\circ}$. The four different DTC combinations (DTC-I, II, III and IV) for a three-level five-phase induction motor drive are investigated for improving the performance of five-phase induction motor. All four of the DTC strategies utilize a combination of the same large and zero voltage vectors, but with different medium voltage vectors. Out of these four techniques, DTC-II gives the best performance when compared to the others. This DTC-II technique is analyzed in detail for improvements in the performance of five-phase induction motor in terms of torque ripple, x-y stator flux and Total Harmonics Distortion (THD) of the stator phase current when compared to its two-level counterparts. To verify the effectiveness of the proposed three-level five-phase DTC control strategy, a DSP based experimental system is build. Simulation and experimental results are provided in order to validate the proposed DTC technique.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2008년도 제49회 학술심포지움 및 국제학술대회
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• pp.33.1-33.1
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• 2008