• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1406-1407
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• 2007

본 논문에서 제안한 ac-PDP(Plasma display panel) 셀구조는 Long gap의 전극 사이에 보조 전극을 삽입한 구조이다. 일반적으로, long gap 구조를 가진 PDP cell은 높은 방전 개시 전압을 가지므로, Long gap 전극 사이에 보조전극을 삽입하여 방전 개시 전압을 낮춤과 동시에 휘도 상승, 소비 전력의 감소효과로 발광효율의 향상을 가져왔다. 제안한 구조의 구동을 위하여 asymmetric mode와 long gap mode라는 2가지 파형을 가지고 실험하였다. 두 파형은 공통적으로 기존의 ADS(Address and Display period Separated)파형을 Y(Scan), Z(Common), A(Address) 전극에 인가하였으며, 보조적극에는 Z(Common) 전극의 파형을 수정한 형태로 인가하였다. Asymmetric mode는 보조전극에 Z(Common) 전극에 인가되는 파형과 같은 형태의 파형을 인가하여 Long gap의 구조를 가지지만 Short gap에서 방전이 가능하도록 설계하였고, long gap mode는 보조전극에 인가되는 Z(Common) 파형 중 sustain pulse를 초기 3개만을 주어 Short gap에서 방전을 개시함과 동시에 priming 입자를 생성하고, 나머지 sustain 구간에서는 floating시켜 이미 생성된 priming 입자를 long gap에서 구동을 가능하도록 하였다.

• Journal of Power Electronics
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• v.17 no.4
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• pp.923-932
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• 2017

This paper proposes a novel scheme which can compensate the common-mode voltage (CMV) for five-level active neutralpoint clamped (5L-ANPC) inverters, which is based on modifying the space vector pulse width modulation (SVPWM) and adding an auxiliary leg to the inverter. For the modified SVPWM, only the 55 voltage vectors producing low CMV values among the 125 possible voltage vectors are utilized, which varies over the three voltage levels of $-V_{dc}/12$, 0 V, and $V_{dc}/12$. In addition, the compensating voltage, which is injected into the 5L-ANPC inverter system to cancel the remaining CVM through a common-mode transformer (CMT) is generated by the additional NPC leg. By the proposed method, the CMV of the inverter is fully eliminated, while the utilization of the DC-link voltage is not decreased at all. Furthermore, all of the DC-link and flying capacitor voltages of the inverter are well controlled. Simulation and experimental results have verified the validity of the proposed scheme.

• Journal of Power Electronics
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• v.19 no.1
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• pp.108-118
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• 2019

This paper proposes a DC-link voltage balance controller using the fourth-phase of a three-level neutral-point clamped (NPC) PWM converter with medium vector selection (MVS) PWM for common-mode voltage reduction. MVS PWM makes the voltage reference by synthesizing the voltage vectors that cannot generate common-mode voltage. This PWM method is effective for reducing the EMI noise emitted from converter systems. However, the DC-link voltage imbalance problem is caused by the use of limited voltage vectors. Therefore, in this paper, the effect of MVS PWM on the DC-link voltage of a three-level NPC converter is analyzed. Then a proportional-derivative (PD) controller for the DC-link voltage balance is designed from the DC-link modeling. In addition, feedforward compensation of the neutral point current is included in the proposed PD controller. The effectiveness of the proposed controller is verified by experimental results.

• Journal of Sensor Science and Technology
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• v.32 no.6
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• pp.432-440
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• 2023

This study introduces an efficient readout circuit designed for two-electrode electrocardiogram (ECG) recording, characterized by its low-noise and low-power consumption attributes. Unlike its three-electrode counterpart, the two-electrode ECG is susceptible to common-mode interference (CMI), causing signal distortion. To counter this, the proposed circuit integrates a common-mode charge pump (CMCP) with a window comparator, allowing for a CMI tolerance of up to 20 V_PP. The CMCP design prevents the activation of electrostatic discharge (ESD) diodes and becomes operational only when CMI surpasses the predetermined range set by the window comparator. This ensures power efficiency and minimizes intermodulation distortion (IMD) arising from switching noise. To maintain ECG signal accuracy, the circuit employs a chopper-stabilized instrumentation amplifier (IA) for low-noise attributes, and to achieve high input impedance, it incorporates a floating high-pass filter (HPF) and a current-feedback instrumentation amplifier (CFIA). This comprehensive design integrates various components, including a QRS peak detector and serial peripheral interface (SPI), into a single 0.18-㎛ CMOS chip occupying 0.54 mm². Experimental evaluations showed a 0.59 µV_RMS noise level within a 1-100 Hz bandwidth and a power draw of 23.83 µW at 1.8 V.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1891-1895
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• 2003

Switch-mode power supplies (SMPS) have become a major source of conducted electromagnetic interference (EMI) which is the combination between differential mode (DM) noise and common mode (CM) noise. This paper presents the conducted EMI reduction approach in flyback switched mode power supply by rerouting for circuit balance to reduce common mode noise. And differential mode noise can be reduce by adding $c_x$ capacitor across the input power line, and passive element to the gate drive of switching device MOSFET to slow down the switching times. This combination of our approach is the effective way to reduce the conducted EMI and it is also a cost effective for product design

• Proceedings of the IEEK Conference
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• 2000.06a
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• pp.13-16
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• 2000

This paper introduces a more effective usage of the limited OVSF cod in compressed mode which is used during inter-frequency/inter-system handover in UTRA(Universal mobile telecommunications system) Terrestrial Radio Access). The usager is to use dynamic common channel which is shared by several users during the compressed mode.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.29 no.2
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• pp.142-145
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• 2018

In this paper, we present a design technique for the suppression of common-mode(CM) noise in switched-mode power supply boards using the segmentation method. By applying the segmentation method, the example structure is decomposed into two segments with decoupling capacitors and a recombination matrix is extracted for the segments. The effects of the decoupling capacitor on CM noise suppression are examined. The simulation time is significantly reduced on using the segmentation method.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.9
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• pp.52-59
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• 2007

Fuel injection system greatly affects the performance of a direct injection diesel engine. A common rail injection system was introduced to satisfy the stringent emission standards, low fuel consumption, and low noise in recent years. The performance of a common-rail fuel injection system is strongly influenced by the injector characteristics. The common rail injector has evolved in order to improve its injection performance. The piezo-actuated injector is more suitable for common rail injection system due to its fast response and is expected to replace current solenoid-operated injector. In this study, nonlinear mathematical models are proposed for the solenoid-operated and the piezo-actuated injectors for control applications. Based on these models, the injection rate, which is one of the most important factors for the injection characteristics, is estimated using sliding mode observer. The simulation results and the experimental data show that the proposed sliding mode observers can effectively estimate the injection timing and the injection rate for both common-rail injectors.

• Proceedings of the KIPE Conference
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• 2001.10a
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• pp.384-389
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• 2001

New methods are studied that can suppress EMI noises, especially common mode currents produced in the motor drive system. One is a packaging technique that forms power converters using a four-layer printed power circuit board. The other is a method based on the generation mechanism of common mode currents which was developed from experimental analyses. It is proved by experiments that the former can effectively control common mode currents, including radiated emissions, and the latter can suppress them without any compensators between the inverter and the motor.

• Proceedings of the KIPE Conference
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• 2004.07b
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• pp.769-773
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• 2004

Conventional SVPWM method has null switching vectors. Null switching vectors cause high common-mode voltage in induction motor drive system. The newly developed common mode voltage reduction PWM technique don't use zero switching state for inverter control. It is realized by changing software without additional hardware. Simulation and experimental results show that proposed method are reduced common mode voltage more than conventional method.