• Journal of Electrical Engineering and Technology
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• 제12권1호
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• pp.256-261
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• 2017

This paper deals with the experimental evaluation on power loss of a double-side permanent magnet synchronous motor/generator (DPMSM/G) applied to a flywheel energy storage system (FESS). Power loss is one of the most important problems in the FESS, which supplies the electrical energy from the mechanical rotation energy, because the power loss decreases the efficiency of energy storage and conversion of capability FESS. In this paper, the power losses of coreless DPMSM/G are separated by the mechanical and rotor eddy current losses in each operating mode. Moreover, the rotor eddy current loss is calculated by the 3-D finite element analysis (FEA) method. The analysis result is validated by separating the power loss as electromagnetic loss and mechanical loss by a spin up/down test.

• 전력전자학회논문지
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• 제5권6호
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• pp.610-619
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• 2000

본 논문에서는 현재 전력저장시스템으로써 가장 많이 사용하고 있는 배터리를 대체할 목적의 5MB (Superconductive Magnetic Bearing)를 이용한 off-line UPS에 관해 연구하였다 영구자석의 덩어리형 고온 초전도 체위에서의 부상득성을 이용하여 베어링 문제의 해결방안에 접근함으로써 고효율의 FES찰 구성하여 단상 off-line UPS에 적용하였으며 제어회로에는 80C 1 96KC 마이크로프로세서를 사용하였고 빠픈 응답윤 요구하는 부분 은 아날로그회로를 사용하여 구성하였다. 에너지 저장모드에서 컨버터 입력천류는 전원전압과 동상의 정현파로 제어하였으며 에너지 회생모드에서는 출력잔압윤 정현파로 제어하기위해 필터커패시터전류릎 직접 제어하였다. 시작 품제작을 통해 시스템의 안장된 동작특성을 확인함으로써 제안된 FES가 Off-line UPS 에서의 에너지 저장매체로써 우수함을 입증하였다.

• 한국정밀공학회지
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• 제20권9호
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• pp.100-108
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• 2003

This paper proposes a flywheel hybrid vehicle to solve the energy crisis problem by the exhaustion of a fossil fuel and air pollution for the conservation of environment. The proposed flywheel hybrid vehicle is composed of an accumulator and a flywheel as the energy generation and storage component and three variable displacement hydraulic pump/motors as the energy transfer devices. Flywheel has the characteristics of high energy density and easy energy absorption and consumption. The effectiveness of the energy-saving of the proposed flywheel hybrid vehicle is verified by simulation using Matlab/simulink. First of ail, analytical modeling for the flywheel hybrid vehicle is presented and simulations are performed based on the experimental efficiency data of a variable displacement pump/motor. The results of the simulation show that the effect of energy savings is realized by the proposed hybrid vehicle in 3 different city driving patterns.

• 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.

• 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 ${\mu}m$.

• Progress in Superconductivity
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• 제13권3호
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• pp.195-202
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• 2012

In this paper, we designed Active Magnetic Bearing (AMB) for large scale Superconductor Flywheel Energy Storage System (SFESS) and PD controller for AMB. And we experimentally evaluated SFESS including hybrid type AMB. The radial AMB was designed to provide force slew rate that was sufficient for the unbalance disturbances at the maximum operating speed. The thrust AMB is a hybrid type where a permanent magnet carries the weight of the flywheel and an electromagnetic actuator generates the dynamic control force. We evaluated the design performance of the manufactured AMB through comparison of FEM analysis and the results of experimental force measurement. In order to obtain gains of PD controller and design a notch filter, the system identification was performed through measuring frequency response including dynamics for the AMBs, a power amp and a sensor using a sine swept test method after levitating the flywheel. Through measuring the current input of the AMBs and the orbit of a flywheel according to rotational speed, we verified excellent control performance of the AMBs with small amount current for the large scale SFESS.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.447-458
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• 2011

In this paper, a novel flywheel energy storage device, called the flexible power conditioner, which integrates both the characteristics of the flywheel energy storage and the doubly-fed induction machine, is proposed to improve power system stability. A prototype is developed and its principle, composition, and design are described in detail. The control system is investigated and the operating characteristics are analyzed. The test results based on the prototype are presented and evaluated. The test results illustrate that the prototype meets the design requirement on power regulation and starting, and provides a cost-effective and effective means to improve power system stability.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1992년도 하계학술대회 논문집 B
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• pp.1052-1054
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• 1992

The conventional serial UPS using battery energy storage unit is almost universally used. Despite its common usage, the conventional UPS has a number of disadvantages which may be effectively overcome by the application of flywheel energy storage unit. This paper proposes a new type of parallel processing UPS using flywheel energy storage unit, which has the feature of high power, long life, and high efficiency.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.963-967
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• 2007

Flywheel energy storage systems (FESS) have advantages over other types of energy storage methods due to their infinite charge/discharge cycles and environmental friendliness. The system has two radial bearings and one hybrid-thrust bearing. Thrust hybrid-type bearing use permanent magnet to relieve gravity load. The radial bearings were designed to provide sufficient force slew rate considering the unbalance disturbance at the operating speeds. In this paper, we will derive dynamic model of hybrid-type bearing using permanent magnet for thrust bearing and present simulation and stability of the model.

• 한국생산제조학회지
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• 제23권5호
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• pp.443-449
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• 2014

This study aims to develop a Flywheel Energy Storage System (FESS) that uses wind power produced when an urban train is in motion, by utilizing a mounted turbine. This system was designed to generate and store electric power from wind power of a travelling urban train. The flywheel was designed to continue rotation using a one-way clutch bearing installed in the turbine shaft pulley, even in cases where the urban train decelerates or stops. This FESS can generate an additional 44% of electric power in comparison to a system not equipped with a flywheel. The generated power and operational features of the FESS were evaluated and verified through a wind tunnel test. The results show that the electric power stored in the FESS could supply auxiliary power for urban train components or service equipment, such as charging mobiles, Wi-Fi modules, and electric lights.