• International Journal of Control, Automation, and Systems
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• v.6 no.5
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• pp.670-676
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• 2008

While the matrix converter has many advantages that include bi-directional power flow, a size reduction, a long lifetime, and sinusoidal input currents, it is vulnerable to the input voltage disturbances, because it directly exchanges the input voltage to the output voltage. So, in this paper, a critical evaluation of the effect of various abnormal voltage conditions like unbalanced power supply, balanced non-sinusoidal power supply, input voltage sags and short time blackout of power supply on matrix converter fed induction motor drives is presented. The operation under various abnormal conditions has been analyzed. For this, a 230V, 250VA three phase to three phase matrix converter (MC) fed induction motor drive prototype is implemented using DSP based controller and tests have been carried out to evaluate and improve the stability of system under typical abnormal conditions. Digital storage oscilloscope & power quality analyzer are used for experimental observations.

• Proceedings of the Acoustical Society of Korea Conference
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• autumn
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• pp.17-20
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• 1999

본 논문에서는 중첩 가산 Sinusoidal 합성방식에서 위상계승에 의한 단위음 연결법과 다프레임간 정현파 크기의 보간법을 제안한다. 그리고 합성 프레임의 중심이 pitch onset time이라고 가정하고, 음성에서 분리한 성도 모델의 위상을 음성 전체의 위상으로 사용하는 방법을 제안한다. 제안한 방법으로 문서-음성 변환 시스템 (Text-to-Speech System, TTS System)을 구현한 결과 단위음 연결시 연결부분의 파형 왜곡이 감소함을 알 수 있었고, 부드럽게 연결된 합성음을 얻을 수 있었다.

• Proceedings of the KIEE Conference
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• 2006.04b
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• pp.140-142
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• 2006

Cogging torque is often a principal source of vibration, noise and difficulty of control in permanent-magnet brushless DC motors. Cogging torque can be minimized by sinusoidal air-gap flux density waveform because it is produced by the interaction of the rotor magnetic flux and angular variation in the stator magnetic reluctance. Therefore, this paper will present a design method of magnetization system of bonded isotropic neodynium-iron-boron(Nd-Fe-B) magnets in ring type with sinusoidal air-gap flux density distribution and low manufacturing cost. An analytical technique of magnetization makes use of two-dimensional finite element method(2D FEM) and Preisach model that expresses the hysteresis phenomenon of magnetic materials in order for accurate calculation.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.372-375
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• 1996

In this paper, a new active interphase reactor for twelve-pulse diode rectifiers is proposed. The proposed system draws near sinusoidal currents from the utility. In this scheme, a low kVA(0.02 $P_o$ (PU)) active current source injects a triangular current into an interphase reactor of a twelve-pulse diode rectifier. The modification results in near sinusoidal input current with less than 1% THD. Experimental results are provided from a 208V, 10kVA rectifier system.

• Proceedings of the KIEE Conference
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• 1996.07a
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• pp.415-419
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• 1996

This paper presents motor speed and phase angle detection method using a sinusoidal AC tachogenerator. The 2-phase or 3-phase output tacho-generator can be adopted, and its' output voltages must have sinusoidal waveforms. Because the detection algorithm is simple, the proposed method can be implemented with analog devices of microprocessor conveniently. And the proposed method has a very short detection delay time. Especially in the analog implementation, there is no delay time without the settling time of analog devices. With the Experimental results, it is verified that the proposed method can accurately detect the instantaneous motor speed and phase over the wide ranges.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1990.10a
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• pp.23-27
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• 1990

A new signal processing system for real time displacement measurement in sinusoidal phase modulating interferometry is described. Although sinusoidal phase modulating interferometry is effective in measuring with high accuracy the displacement of an object, conventional signal processing takes a long time. In this method, detection of the object's displacement is easily achieved by sampling the interference signal at those times that satisfy certain conditions and by processing the sampled signals with electric circuits in real time. The delay time of this signal processing system is < 45${\mu}$s. Specially in this paper we describe all electronic circuit and optical system design

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.05a
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• pp.13-18
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• 2001

This paper deals with finite element analysis for free vibration and forced sine vibration of Ka- and Ku- bend antenna structures using MSC/PATRAN/NASTRAN. The structures are designed to satisfy minimum resonance frequency requirement in order to decouple the dynamic interaction of the satellite with the spacecraft bus structure. From the forced sinusoidal vibration, we have observed output acceleration versus input in X-,Y- and Z- direction, based on base excitation using large mass method. The results of finite elements analysis can be used as the reference data for the experimental test of satellite antenna, resulting in the reduction of cost and time by predicting and complementing experimental data.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2005.06a
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• pp.260-264
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• 2005

This paper describes the ultra precise position control of servo motor using sinusoidal encoder based on 'Arcsine Interpolation Method'. First, the paper theoretically analyzes and verify throughout experiments, the relationship between A/D converter input ripple and the total resolution to measure the precise position. Second, this paper presents a way to compensate the total gain and offset error by utilizing a low cost programmable differential amp, by which without any special expensive equipments they are easily on-line tuned and effectively compensated. Lastly, it was compared to servomotor position control characteristics using digital incremental 50,000ppr encoder. The test results show that, with much cheaper sinusoidal encoder, the proposed method exhibits better performance both in position control and ASD applications than the 50,000ppr optical encoder.

• Journal of Power Electronics
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• v.9 no.5
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• pp.791-799
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• 2009

This paper presents a time-varying sinusoidal disturbance compensation method (based on an adaptive estimation scheme) for induction motor drives fed by a matrix converter. In previous disturbance accommodation methods, sinusoidal disturbances with unknown time-invariant frequencies have been considered. However, in the new method proposed here, disturbances with unknown time-varying frequencies are considered. The disturbances can be estimated by using a disturbance accommodating observer, and an additional control input is added to the induction machine drive. The stability analysis is carried out considering the disturbance estimation error and simulation results are shown to illustrate the performance of the proposed solution.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.11b
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• pp.687-692
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• 2002

In order to verify the effectiveness of adding visooelastic dampers to full-scale steel frame structure on the reduction of their seismic and wind response a experimental work was carried out. First, The test was conducted on the VE dampers subjected to sinusoidal excitations under a variety of ambient temperatures, frequency, and the damper strain. Results from these tests showed that the viscoelastic dampers have high energy dissipation capacity. Second, The vibration tests was conducted of the full-scale steel frame structure with md without added VE dampers at different temperatures. Viscoelastically damped full-scale structure test result on the effect of ambient temperature show that viscoelastic dampers are very effective in reducing excessive vibration of the structure due to sinusoidal excitation over a wide ringe of ambient temperature.