• 자동차안전학회지
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• 제3권2호
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• pp.5-10
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• 2011

Under the full frontal crash event, seatbelt system is the most typical and primary restraint device that prevents the second impact between an occupant and vehicle interior parts by limiting the forward motion of an occupant in the vehicle occupant packaging space. Today's restraint systems typically include the three-point seat belt with the pretensioner and the load limiter. A pretensioner preemptively tightens the seat belts removing any slack between a passenger and belt webbing which leads to early restraint of a passenger. After that a load limiter controls level of belt load by releasing the belt webbing to reduce occupant injurys. In this study, load characteristics of load limiters are optimized by the computer simulation with a MADYMO model for a frontal impact against the rigid wall at 56kph and then we suggest performance requirements. We derived optimum load characteristic from the results using four vehicle simulation models represented by the vehicle. Based on the results, we suggest the performance from the results of the second optimization using the simulation considering the design and the standardization. Finally, the performance requirements is verified by the sled tests including the load limiter device for the full vehicle condition.

• 대한기계학회논문집A
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• 제35권10호
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• pp.1187-1191
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• 2011

이 응용논문에는 적응형 로드리미터에 대해 기술되어 있다. 적응형 로드리미터는 안전벨트의 구성품 중 하나이며, 이는 승객의 다양한 체중과 키에 따라 하중량을 고하중과 저하중으로 변환시킬 수 있는 장치이다. 최근, FMVSS 208규정은 다양한 더미크기에 대해 엄격한 안전기준을 요구하고 있다. 이에 따라 우리는 고하중 조건과 저하중 조건 시 각각 더미에 흉부 상해정도를 알아보았고, 실험을 통해서 벤치마킹모델의 하중조건을 확인하였다. 이를 토대로 적응형 듀얼레벨 로드리미터를 개발하여 성능 실험을 실시하였고, 유한요소해석을 통해 설계 개선점을 확인하였다.

• 한국기계가공학회지
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• 제9권1호
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• pp.35-41
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• 2010

An overload limiter is used to prevent its overturning accident during an operation of a movable crane. Recently the indirect measuring method, which measures hoisting load and overturning moment of overload limiter, demands instead of the existing method, which measures only hoisting load. The indirectly measuring method is how to conduct the hoisting load and overturning moment as measuring the load of hydraulic cylinder for a luffing driving of boom. So we need to develop the multi-angular pin type load cell with the measuring angle of ${\pm}10$ degree instead of the existing load cell with the measuring angle of ${\pm}2$ degree. In this study the finite element analysis is conducted to evaluate the effect of the aspect ratio of measuring cross section on the measuring limit of the load cell to develop the many-angular pin type load cell. For this investigation, the aspect ratio of measuring cross section and load applying angle were adopted as design parameters and the stresses of measuring part were evaluated for each parameter.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2001년도 전력전자학술대회 논문집
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• pp.288-291
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• 2001

In steel plant, load torque of mill driver motor is changed periodically because working state and idle state are repeated and load current of working state is necessarily higher than rated motor current. The over current limiter is one of the basic thermal protection method from over heating. In this paper, we analyzed the structure of over current limiter for motor and motor driver systems, developed over current limiter with same operation and structured warning system of action of over current limiter. As using this warning system, we can avoid abrupt plant stop by over current limiter in mill driver and lessen producing loss by plant stop. The developed warning system of action of over current limiter is exactly inspected by computer simulation md analysis of acquired data.

• Nuclear Engineering and Technology
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• 제32권2호
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• pp.191-203
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• 2000

This paper describes the beneficial effect of weldment imperfection of the cask impact limiter, by applying intermittent-weld, for impact energy absorbing behavior. From the point of view of energy absorbing efficiency of an energy absorber, it is desirable to reduce the crush load resistance and increase the deformation of the energy absorber within certain limit. This paper presents the test results of intermittent-weldment and the analysis results of cask impacts and the discussions of the improvement of impact mitigating effect by the imperfect-weldment. The rupture of imperfect weldment of an impact limiter improves the energy-absorbing efficiency by reducing the crush load amplitude without loss of total energy absorption. The beneficial effect of weldment imperfection should be considered to the cask impact limiter design.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 학술대회 논문집
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• pp.182-185
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• 2003

Temperature distribution and cooling load in binary current lead are analized, occurring fault current at DC Reactor type superconductor fault current limiter. It is assumed that Normal operating current is 300 A and fault current is 3000 A. Unsteady-state temperature distribution and cooling load of brass current lead optimized for 300 A and 1000 A are calculated by numerical method with TDMA. In the result of calculation, temperature increase in the brass current lead optimized for 300 A is higher than that in the brass current lead optimized for 1000 A, but the temperature increase in the brass current lead optimized for 300 A is not serious. Moreover, increase of cooling load in the brass current lead optimized for 300 A is higher than that in the brass current lead optimized for 1000 A, but normal cooling load in the brass current lead optimized for 300 A is lower than that in the brass current lead optimized for 1000 A. Therefore, designing current lead in superconductor fault current limiter had better to optimize for normal operating current.

• 대한전기학회논문지
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• 제43권7호
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• pp.1050-1060
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• 1994

This paper is a study on the computer simulation of the characteristics of the superconducting fault current limiter. Input variable parameters are apparent power, load resistance value, line resistance value and so on. Initial fault current 2 times larger than the trigger current is required to reduce the switching time of SFCL. The propagation velocity increases abruptly, the transport current is several times larger than the ciritical current. In this paper, the switching time is calculated to be 323$\mu$ sec, and the initial fault current is 19 times larger than the critical current. Because the trigger coils are bifilar winding, they have little impedance in superconducting state. After fault occurred, the limiting coil acts as a superconducting reactor and the trigger coils quench at a critical current. Without the SFCL in the circuit, fault current after the load impedence is shorted might be increased to 1100A. The fault current is, therefore, successfully limited by the superconducting limiting coil to 100A determined by the coil inductance.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1368-1370
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• 2005

Satellite is operated only with internal battery when separated from rocket. Internal battery is charged only from SAR(solar Array Regulator), solar cell. So battery will be exhausted and purpose of satellite will be failed if load module is out of order or short. This paper proposed real time current limiter which operated by telemetry of outer processor. This current limiter operates by control signal simultaneously cuts off over current by self over current sensing circuit. So it can reduce waste of battery energy and over load of outer processor.

• 항공우주기술
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• 제10권2호
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• pp.56-64
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• 2011

최근 위성 시스템의 전력분배는 기존의 퓨즈와 릴레이로 구성된 것과는 달리 LCL(Latching Current Limiter) 회로로 구현되어, 각각의 부하전원을 단속한다. LCL은 부하에서 생기는 과전류를 제한함으로서 고장 의심이 있는 부하를 물리적으로 차단하는 기존 방법에 비하여 고장의 원인을 분석하고, 일시적인 고장인 경우 부하를 재사용할 수 있는 장점이 있다. 그러나 LCL 회로는 전자소자로 구현되는 만큼 주변회로(부하회로)와의 연동성과 회로 자체의 특성을 이해해야 하며, 무엇보다 과전류를 차단하기 위하여 설정하는 LCL 동작 파라미터의 정의를 위한 기술적인 접근이 요구된다. 따라서 본 논문에서는 전력분배 모듈의 LCL 동작 파라미터를 정의하기 위한 분석을 수행했고, 회로구현 및 특성 시험결과를 나타냈다.

• 전기학회논문지
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• 제61권11호
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• pp.1752-1757
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• 2012

With the development in industry, power demand has increased rapidly. As consumption of power has increased, Demand for new power line and electric capacity has risen. However, in the event of fault, problems occur in extending the range of fault coverage and increasing fault current. In these reasons, protection devise is recognized as the prevention of an accident and fault current. This paper dealt with minimizing fault propagation and limiting fault current by adjusting fault current limiter (FCL) with fast interrupter. At this point, we compared and analyzed characteristics between non-inductive resistance and fault current which is limited by superconducting units. In normal state of the power system, power was supplied to the load, but when fault occurred, the interrupter was operated as CT which detected the over-current. Its operation made the limitation of fault current through a FCL. We concluded that the limiter using superconducting units was more efficient with the increase of power voltage. Superconducting fault current limiter with the fast interrupter prevented the spread of a fault, and improved reliability of power system.