• Structural Engineering and Mechanics
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• 제5권1호
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• pp.21-32
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• 1997

A new torsional analysis method for multiple cell box based on the Softened Truss Model Theory was developed. This softened truss model unifies shear and torsion to address the problem associated with a torque applied on a box. The model should be very useful for the analysis of a reinforced concrete box under torque, especially for the bridge superstructure with multiple cell box sections.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.693-696
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• 2011

The SRM (Switched Reluctance Motor) is composed of silicon steel plates where the rotor structure is simple and laminated without coil winding or permanent magnet, making it mechanically robust and its maintenance and repair excellent. Applying SRM as traction motor for railway vehicle is given consideration because of its ruggedness capability in severe loading condition and its compact structure. Optimal design of SRM is needed to reduce torque ripple to apply SRM for railway traction drive because SRM has high torque ripple. In this paper, switched reluctance motor with three different stator pole shapes is taken for magnetic analysis using 3d finite element method to apply SRM as traction drive for railway vehicle. It is observed that the model 3 added Tooth Tang Depth and Slot Round to stator shape gives the improved inductance and torque characteristic.

• Journal of Electrical Engineering and Technology
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• 제10권1호
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• pp.188-194
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• 2015

This paper proposes a generalized regression neural network (GRNN) based algorithm for data interpolation and design optimization of brushless dc (BLDC) motor. The procedure makes use of magnet length, stator slot opening and air gap length as design variables. Cogging torque and average torque are treated as performance indices. The optimal design necessitates mitigating the cogging torque and maximizing the average torque by varying design variables. The data set for interpolation and ensuing design optimisation using GRNN is obtained by modeling a standard BLDC motor using finite element analysis (FEA) tool MagNet 7.1.1. The performance indices of the standard motor obtained using FEA are validated with an experimental model and an analytical method. The optimal design is authenticated using particle swarm optimization (PSO) algorithm and the performance indices of the optimal design obtained using GRNN is validated using FEA. The results indicate the suitability of GRNN as an interpolation and design optimization tool for a BLDC motor.

• 조명전기설비학회논문지
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• 제26권2호
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• pp.71-77
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• 2012

The cogging torque is important to the cut-in wind speed. And, it causes the acoustic noise and the vibration on the machine. This paper presents a 3D FEA(Finite Element Analysis) to evaluate the effect of magnet skew and stator displacement on cogging torque reduction, for double core AFPM(Axial Flux Permanent Magnet) generator. As a result, the magnet skew and the stator side displacement are proved excellent techniques to reduce the cogging torque.

• Journal of international Conference on Electrical Machines and Systems
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• 제2권4호
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• pp.390-393
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• 2013

In this paper, we proposed how the V-skew applied of the rotor to inprove the characteristics of cogging torque in large PMSM. Large PMSM is difficult to apply a pitch of the diagonal magnetic skew because of the motor's structure and making. In addition, the force in the direction of z-axis occurs when the diagonal skew is applied. So we are applying the optimal v-skew to reduce torque ripple and cogging torque because this reduces the noise and vivration on the motor. Throug FEM dD analysis, we studied to find the optimal v-skew angle for reducing torque ripple.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.613-618
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• 2001

For the evaluation of operability of MOV(Motor Operated Valve), the precision prediction of thrust/torque acting on the valve is important. In this paper, the analytical prediction method of thrust/torque was proposed. The design basis stem thrust calculation typically considers the followings: Packing thrust, Stem rejection load, design basis differential pressure load. In general, test results show that temperature, pressure, fluid type, and differential pressure, independently and combination, all have an effect on the friction factor. The prediction results of thrust/torque are well agrement with dynamic test results.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 춘계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.3-5
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• 2008

This paper presents a hybrid winding connection method for torque characteristics improving of a traction SRM. In order to get a high torque in wide speed range and torque ripple reduction, series and parallel winding connection are changed according to operating speed. From the analysis of torque character operation mode and efficiency, the proposed control scheme is verified.

• 대한전기학회논문지:전기기기및에너지변환시스템부문B
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• 제55권6호
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• pp.287-291
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• 2006

Recently, various applications of permanent-magnet(PM) electric motor have been more increased. Compared with the other electric motors, PM electric motor has cogging torque which results from the interaction between PM of rotor and slot-teeth structure of stator. Audible noise and vibration is caused by this cogging torque. So, the reduction of cogging torque is main designing goal of PM electric motor. The purpose of this paper is to realize the decrease of cogging torque using new experimental design and response surface analysis which is one of the statistical methodologies.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1996년도 하계학술대회 논문집 A
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• pp.145-147
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• 1996

Traction Motor is being transferred to the squirrel cage induction motor from D.C motor, by the improved power semiconductors like GTO, IGBT, etc. In the Induction Motor, inverter system must be used for delivering variable voltage variable frequency. But, by pulsating in the system the harmonics would be produced, and that cause the torque ripple and enfeeble the dynamic characteristics of the motor. So, to use the inverter system, we should take the torque ripple into consideration. To minimize the torque ripple in the VSI fed Traction Motor, the optimal pulsating was presented in this paper. By using the SPWM(Sinusoidal Pulse Width Modulation) method, feeding the appropriate pulse, we can minimize the torque ripple and improve the transient response.

• Journal of Advanced Marine Engineering and Technology
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• 제25권5호
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• pp.1065-1075
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• 2001

It is common knowledge amongst electrical and marine engineers that short-circuit in electrical system may cause large mechanical torque on generator and prime mover However, it is not so widely known that the faulty synchronizing of generators may cause even higher torques than that of short-circuit. In this study, the transient phenomena related to the parallel running of synchronous generators are analyzed and the exact computer simulation method is proposed. In result, maximum transient torque and current take place in case of $120^{\circ}$ voltage angle difference between Master and Slave and that may develop higher torque than the short-circuit according to a condition of synchronizing. When synchronizing in power system using only two generators higher torque and current occur Master, but using multimachine system those occur to Slave. The short-circuit of marine generator does not happen frequently but faulty synchronizing sometimes takes place, therefore, it is necessary for designers to consider these phenomena.