• 전력전자학회논문지
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• 제10권5호
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• pp.494-500
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• 2005

본 논문에서는 플라이휠에너지를 이용한 다이나믹 UPS 시스템에서 유도기를 이용하여 플라이휠의 에너지를 저장 및 재생하는 시스템 제어 기법을 제시하였다. 유도발전기의 슬립주파수 제어와 벡터제어 기법의 특성을 비교하고, 또한 벡터제어 기법을 사용 시 전동 모드에서 발전 모드로의 전환할 때 직류링크 커패시터 전압의 과도 특성을 개선하는 기법을 개발하였다. 32비트 DSP를 사용한 실험을 통하여 이 기법의 성능을 확인하였다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2002년도 ICCAS
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• pp.66.1-66
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• 2002

Today it becomes a serious problem to exhaustion of a fossil fuel and air pollution by exhaust gases from road vehicles for environment preservation. To solve this problem, the developments of a hybrid vehicle have been processed for the purpose of reducing pollution and energy-savings. By the way, flywheel hybrid vehicle using variable pump/motor was proposed as one feasible hybrid system in place of hybrid vehicle system by the conventional storage battery. The proposed flywheel hybrid vehicle is composed of an accumulator or a flywheel as the energy generation and storage source and three variable hydraulic pump/motor as the energy transfer device. Flywheel has the characteristic of high...

• 대한기계학회논문집
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• 제19권7호
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• pp.1665-1674
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• 1995

An optimum design has been performed to maximize specific energy (SED) of composite flywheel rotor for energy storage system. The flywheel rotor is assumed to be an axisymmetric thick laminated shell with a plane strain state for structural analysis. For the structural analysis the centrifugal force is considered and the stiffness matrix equation was derived for each ring considering the interferences between the rings. The global stiffness matrix was derived by integrating the local stiffness matrix satisfying the conditions of force and displacement compatibilities. Displacements are then calculated from the global stiffness matrix and the stresses in each ring are also calculated. 3-D intra-laminar quadratic Tsai-Wu criterion is then used for the strength analysis. An optimum procedure is also developed to find the optimal interferences and lay up angle to maximize SED using the sensitivity analysis.

• 한국기계가공학회지
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• 제11권2호
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• pp.137-143
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• 2012

This study analyzes flywheel through the analyses of stress, fatigue and vibration. Maximum equivalent stress is 15.271MPa at the mid round shape and maximum deformation is 0.02264mm at the outer teeth. Among the cases of nonuniform fatigue loads, 'SAE bracket history' with the severest change of load becomes most unstable but 'Sample history' becomes most stable. In case of 'Sample history' with the average stress of -$10^4$MPa and the amplitude stress of 1000 to 2900MPa, the possibility of maximum damage becomes 30%. This stress state can be 20 times greater than the damage possibility of 'SAE bracket history' or 'SAE transmission'. The range of natural frequencies becomes 200 to 820Hz and the values of these deformations are not more than 10mm. The structural result of this study can be effectively utilized with the design of flywheel by investigating prevention and durability against its damage.

• 한국자동차공학회논문집
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• 제5권3호
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• pp.106-116
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• 1997

In this paper, using MATLAB SIMULINK, a generalized design methodology was suggested for multi pass transmission(MPT) by classifying the vehicle power train as prime mover, MPT and vehicle dynamics. This approach enables a designer to investigate the influence of each transmission component by simple combination of system components without changes of overall program. Using the design methodology, a MPT consisting of CVT, 2, clutches and reduction gears was designed for a braking energy regenerative flywheel hybrid vehicle. The CVT is essential in order to connect the engine and flywheel speed with the vehicle speed. For the purpose of smooth clutch operation, control algorithm was suggested by introducing dead zone for the clutch engagement. Using the SIMULINK model, performance of the flywheel hybrid vehicle with MPT was investigated. It was observed from the simulation results that the MPT vehicle showed better fuel economy, 47% than that of AT vehicle, 27% than that of CVT vehicle for ECE-15 driving cycle. Especially destinct fuel efficiency improvement was obtained for city driving cycle requiring more frequent stop and start.

• Journal of Power Electronics
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• 제1권2호
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• pp.127-132
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• 2001

This paper describes two different systems which can compensate harmonic currents generated in a power system. As non-linear loads increase gradually in industry fields, harmonic current generated in the electric power network system also increases. Harmonic current makes a power network current distorted and generates heat, vibration and noise in the power machinery. Many approaches have been applied to compensate harmonic currents generated in the power system. Among various approaches, in this paper, two kinds are compared and evaluated. They are flywheel compensators bases on secondary excitation of WRIM(wounded rotor induction motor) and SCIM(squirrel cage induction motor). Both systems have a common structure. They use a flywheel as an energy storage device and use PWM inverters. The main differences are the size and rating of the converter used.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 춘계학술대회
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• pp.485-490
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• 2004

Flywheel Energy Storage System(FESS) consists of a high speed flywheel with an integral motor/generator suspended on non contact bearings and in an evacuated housing. Permanent magnet machines as the FESS motor/generator are a popular choice, since there are no excitation losses which means substantial increase in the efficiency. In this paper, the structural design method of rotor retainer for a high speed motor/generator are presented.

• 한국철도학회논문집
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• 제4권1호
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• pp.16-22
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• 2001

This paper describes two different systems which can compensate harmonic currents generated in the power system. As non-linear loads increase gradually in industry fields, harmonic current generated in the electric power network system also increases. Harmonic current makes a power network current distorted and generates heat, vibration, noise in the power machinery. Many approaches have been applied to compensate harmonic currents generated in the power network system. Among various approaches, in this paper, two kinds of approaches are compared and evaluated. They are flywheel compensator based on secondary excitation of wounded rotor induction motor(WRIM) and primary excitation of squirrel cage induction motor(SCIM). Both systems have a common structure. They use a flywheel as a energy storage device and use PWM inverters.

• 전기학회논문지
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• 제58권9호
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• pp.1750-1756
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• 2009

In this paper, 5 kWh class Superconductor Flywheel Energy Storage System (SFES) was constructed including motor/generator, superconductor magnetic bearing(SMB), composite rotor and electromagnetic damper(EMD) system. High speed rotation test was performed after levitating flywheel rotor only using EMD without SMB. the PD controller of EMD was designed. the control system is constructed using xPC which is real time digital control system. the results of high speed rotation test showed that proposed EMD system have sufficient damping in cylindrical mode and conical mode, and vibration of wheel was suppressed below 10 ${\mu}m$.

• 전력전자학회논문지
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• 제7권1호
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• pp.74-80
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• 2002

철도차량용 추진시스템은 안전성과 신뢰성 때문에 성능을 평가해야만 한다. 일반적으로 Flywheel Type시험방법은 시험설비로 널리 사용되고 있다 그러나 Flywheel에 의해 생기는 기계적 관성은 변하기 어렵고 실제적인 주행저항을 표현할 수 없다. 본 연구는 다양한 차량부하의 개발에 초점을 두고 수행되었다. 그렇기 때문에 실제적인 차량 부하 특성을 얻기 위해 벡터모터에 의해 제어되는 다양한 차량부하를 사용하는 방법을 제안하였고 컴퓨터 시뮬레이션을 통해 결과를 확인하였다.