• Journal of Industrial Technology
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• v.30 no.B
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• pp.109-112
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• 2010

Unlike the general lighting systems, stage lighting system requires accurate dimming control and reduction of flicker phenomenon. In this paper, we studied PWM dimming control and linear voltage level control methods. PWM Dimming is easy control and flicker phenomenon of linear voltage level dimming does not happen by experiment result. We concluded that stage lighting dimming system required to combine two techniques of the PWM and linear voltage level dimming control method.

• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.302-304
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• 2005

본 논문에서는 입력단 역률제어 및 고조파 전류억제를 위해 PWM 컨버터를 이용하는 3상 UPS에서 직류측을 공통으로 연결하여 하나의 배터리 유닛만으로 병렬 UPS운전이 가능한 공통 배터리 운전에 대해 기술한다. 직류측을 공통으로 이용함으로써 PWM 컨버터 간에 흐를 수 있는 순환전류를 없애기 위한 제어기를 제안하고 실험을 통해 제안한 방법의 타당성을 검토한다.

• The Transactions of the Korean Institute of Power Electronics
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• v.2 no.2
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• pp.41-48
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• 1997

Nowadays, EMI emission characteristics, which causes harmful effect on power distribution system and other equipments, have been studied in field of Power electronics, vigoriously. So, in this paper, the conducted EMI emission is measured and compared for 3-phase diode rectifier and PWM converter according to switching frequency variation and current control method change using LISN(Line Impedance Stabilization Network) and spectrum analyzer.

• The Transactions of the Korean Institute of Power Electronics
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• v.8 no.1
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• pp.64-69
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• 2003

There exist the high frequency components, which can not be predicted by the low frequency model, due to the presence of sampling effect in current mode control. In this paper, the output voltage equations for the ZVS half bridge PWM convertor are derived from the steady state analysis, and the sampling gain presented in the current control loop is Investigated to improve the Prediction Performance of low frequency model of ZVS half bridge PWM converter.

• Journal of the Korean Society for Precision Engineering
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• v.22 no.8 s.173
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• pp.64-70
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• 2005

The development of an accurate and energy saving pneumatic regulator that may be applied to a variety of practical pressure control applications is described in this paper. A novel modified pulse width modulation(MPWM) valve pulsing algorithm allows the pneumatic regulator to become energy saying system. A comparison between the system response of conventional PWM algorithm and that of the modified PWM(MPWM) algorithm shows that control performance is almost the same, but energy saving is greatly improved by adopting this new MPWM algorithm. The effectiveness of the proposed control algorithm are demonstrated through experiments with various reference trajectories.

• Proceedings of the KIPE Conference
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• 2018.07a
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• pp.392-393
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• 2018

BLDC 전동기는 역기전력이 사다리꼴이며 운전은 전기각 $60^{\circ}$로 구분되어 상전환이 이루어진다. 이와 같은 $60^{\circ}$ 구간에서 전압은 균일하게 인가되어야 하며, 이를 위하여 시비율을 조절하고 각 구간마다 균일한 전압이 출력될 수 있도록 한다. 그러나 $60^{\circ}$의 상전환 시점과 PWM의 인가시점이 일치하지 않으며, 이에 따라 시비율을 일정하게 제어하더라도 각 $60^{\circ}$구간의 전압이 균일하지 않게 될 수 있다. 이와 같은 현상은 $60^{\circ}$ 구간의 시간이 짧아져서 PWM 펄스개수가 줄어드는 고속 구간에서 오차가 더 크게 반영될 수 있다. 이를 보완하기 위하여 본 논문에서는 PWM의 주기 시점과 상전환 시점을 동기화하여 제어하는 방안을 제안하고, 시험을 통하여 검증하였다.

• Proceedings of the KIPE Conference
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• 2013.07a
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• pp.70-71
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• 2013

PV Simulator는 태양광발전용 Power Conditioning System (PCS)을 개발하거나 제품 출하 시 성능을 시험하기 위하여 필요한 장비이다. 본 논문에서는 3상 PWM 컨버터로 안정된 직류전압원을 확보하고, 3대의 DC-DC 컨버터에 의하여 각각의 PV array에 대한 I-V 특성을 독립적으로 모사할 수 있는 구조의 PV Simulator를 제안한다. 제안된 PV Simulator의 동적 성능을 확보하기 위하여는 DC-DC 컨버터에서 요구하는 순간적인 전류 외란에 대하여 강인하고 안정적인 DC전압을 공급해주는 3상 PWM 컨버터의 성능이 요구된다. 본 논문에서는 부하전류의 외란에 대한 3상 PWM 컨버터의 전압응답 특성을 분석하고, 외란에 강인한 제어기를 설계하고 제어게인을 선정한다. 시뮬레이션과 실험을 통하여 제안된 제어기의 성능이 우수함을 검증한다.

• The Transactions of the Korean Institute of Power Electronics
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• v.3 no.2
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• pp.85-91
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• 1998

This paper describes an study electric injection system for diesel engines. It is needed effective fuel injection which controls the solenoid valve of fuel pump. To solve this, this paper proposes DCC-PWM method which can realize fast reply and low holding current for solenoid valve on/off. For the proposed design method, simulation tools of ACSL are used to analyze the system. And the single-chip microcomputer is used to reduce the size of controller and to improve flexibility. And the systems validity can be verified through the experimental results.

• The Transactions of the Korean Institute of Power Electronics
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• v.10 no.4
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• pp.373-379
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• 2005

In this paper, the control algorithm of DC source device for inverter starting is proposed and the control method for compensating unbalance system source on operating time in the voltage type PWM converter with driving and regenerative faculty is suggested. The maintaining way of balancing condition for converter of AC source is used the compensating unbalanced status by current control loop. Because it is possible that the unbalanced System control is used to leakage transformer not equaled reactance by each phase in rectifier system, the proposed H/W and control algorithm of rectifier system is contributed to minimize of device and rising efficiency.

• The Transactions of the Korean Institute of Power Electronics
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• v.13 no.1
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• pp.55-62
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• 2008

This paper proposes a feedback linearization control scheme of AC/DC PWM converters with LCL input filters using no damping resisters. This feedback linearization scheme can eliminate the non-linearity of the system. So, the controller of the system can be designed by using linear control theory, which gives a good transient response. The cascade structure of the controller makes the converter current be controlled within a certain limit. To reduce the number of sensors, the source voltage and current is estimated. The validity of the proposed control algorithm is verified by simulation and experimental results.