• The Transactions of the Korean Institute of Power Electronics
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• v.17 no.5
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• pp.401-408
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• 2012

A simple on-line elimination strategy of the dead time and inverter nonlinearity using the current slope information is presented for a PWM inverter-fed IPMSM (Interior Permanent Magnet Synchronous Motor) drive. In a PWM inverter-fed IPMSM drive, a dead time is inserted to prevent a breakdown of switching device. This distorts the inverter output voltage, resulting in a current distortion and torque ripple. In addition to the dead time, inverter nonlinearity exists in switching devices of the PWM inverter, which is generally dependent on operating conditions such as the temperature, DC link voltage, and current. The proposed scheme is based on the fact that the d-axis current ripple is mainly caused by the dead time and inverter nonlinearity. To eliminate such an influence, the current slope information is determined. The obtained current slope information is processed by the PI controller to estimate the disturbance caused by the dead time and inverter nonlinearity. The overall system is implemented using DSP TMS320F28335 and the validity of the proposed algorithm is verified through the simulation and experiments. Without requiring any additional hardware, the proposed scheme can effectively eliminate the dead time and inverter nonlinearity even in the presence of the parameter uncertainty.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2013.05a
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• pp.347-348
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• 2013

• Proceedings of the KIPE Conference
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• 2000.07a
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• pp.219-223
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• 2000

In this paper a new current controller with dead time compensation for small time constant PMSM is proposed. Precise analysis on voltage distortion by dead time and device characteristics is presented. Simulation results are presented to demonstrated the validity of the proposed method.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.81-82
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• 2009

• Proceedings of the Membrane Society of Korea Conference
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• 1998.10a
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• pp.133-136
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• 1998

0.1 내지 $4 \mum$의 입도분포를 가진 kaolin용액을 dead-end형 여과 장치(Amicon Cell, 8050)를 이용하여 공칭세공이 $0.2 \mum$인 PTFE막으로 농도 및 운전압력에 따른 투과실험을 하였다. Kaolin 용액의 투과유속은 케이크 저항이 지배적이었으며 초기에는 분리막 표면에 케이크가 형성되고 그 후에 분리막 세공의 오염이 발생하는 것으로 관찰되었다.

• Journal of Power Electronics
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• v.6 no.4
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• pp.279-289
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• 2006

This paper presents a neural network based adaptive dead-time compensation strategy for an inverter fed permanent magnet synchronous motor drive. The neural network is used for identifying the dead-time compensation time (DTCT) that includes an equivalent dead-time, turn-on/off time and on-state voltage components of the voltage source inverter. In order to train the neural network, desired DTCTs for eight operating points are prepared as training data. The trained neural network can identify a desired DTCT for any operating point because it has the capability of the interpolation. The accuracy of the identified DTCT is experimentally confirmed by comparing the calculated active power with a measured one.

• Transactions of Materials Processing
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• v.7 no.2
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• pp.177-185
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• 1998

The kinematically admissible veolcity field is developed for the shapes of dead metal zone and the curving velocity distribution in the eccentric plane dies extrusion. The shape of dead metal zone is defined as the boundary surface with the maximum friction constant between the deformable zone and the rigid zone. The curving phenomenon in the eccentric lane dies is caused by the eccentricity of plane dies. The axial velocity distribution in the plane dies is divided in to the uniform velocity and the deviated velocity. The deviated velocity is linearly changed with the distance from the center of cross-section of the workpiece. The results show that the curvature of products and the shapes of the dead metal one are determined by the minimization of the plastic work and that the curvature of the extruded products increase with the eccentricity.

• Proceedings of the Korea Multimedia Society Conference
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• 2000.04a
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• pp.449-452
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• 2000

This paper proposes a new, adaptive Dead Reckoning model, called Dynamic Dead Reckoning , for Distributed Interactive Simulation and humanoid avatar systems. The proposed model can overcome the weak points of traditional Dead Reckoning caused by a fixed threshold and strong dependency on rotation event. This paper introduces new criteria for update message filtering , named as Update lifetime. The Dynamic Dead Reckoning keeps the balance between extrapolation fidelity and filtering performance by two component models, Variable Threshold Mechanism and Rotation Event model. The experimental results show that the proposed model can lower the increment rate of update traffic to the increase of rotation frequency without any significant loss of accuracy.

• The Korean Journal of Ecology
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• v.8 no.3
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• pp.133-140
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• 1985

Aboveground net productions of four stands in the coastal salt marsh of Incheon were estimated with three different methods: first method was to measure peak live standing crop; second to measure both live and dead standing crops; thrid to measure live and dead standing crops and dead disappearance as well. Net productions estimated by the first method were lowest with a difference of 28~50% from those by the third method. Whereas estimates by the second method approximated considerably to those by the third method with a difference of 4~15%. The third method figured out the highest values and seemed to be most appropriate in estimating net production of herbaceous community. Form these results it is known that live standing crop, dead standing crop and dead disappearance respectively accounted for about 60, 30, 10% of net production estimated by the third method. Annual net productions estimated by the third method for Suaeda japonica-Salicornia herbacea, Artemisia scoparia-Limonium tetragonum, Calamagrostis epigeios, and Sonchus brachyotus-Setaria viridis stand were 650, 1, 080, 1, 409 and 1, 126 g.$m^{-2}.yr^{-1}$, respectively.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.92-94
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• 2005

In this paper, when electric train is in dead-section the effect on electric train system was dealt. The feeding system of electrical railway is AC or DC. When the electric train is passed AC feeding system to DC, vice versa or phase is changed in between AC feeding systems, there is a dead section. A dead section usually makes the electrical system complex md may have an adverse effect on the electrical system inside the train. Accordingly, it is important to analyze the effect on trains in dead-section. Modeling an electric train and simulation using PSCAD/EMTDC was accomplished to analyze how power quality problem such as inverter switching surge is propagated to electric train through the feeding line, railway, pantograph.