• 제목/요약/키워드: Common-mode voltage

검색결과 217건 처리시간 0.026초

Reduction of EMI Generated by a PWM Inverter-Fed AC Motor Dirve System

  • Ogasawara, Satoshi;Akagi, Hirofumi
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 1998년도 Proceedings ICPE 98 1998 International Conference on Power Electronics
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    • pp.452-457
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    • 1998
  • This paper deal with problems of leakage current, shaft voltage, bearing current, and EMI, in valiable-speed AC drives. The originating mechanism is illustrated with a high-frequency equivalent circuit. Reduction methods are classified in to six categories based on the equivalent circuit. Some experimental results show that a common-mode transformer (CMT) and a common-noise canceler (ACC) can solve the problems, which have been proposed the authors.

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An Address Voltage Stabilization Circuit for the Single-Side Driving Method of AC Plasma Display Panels

  • Kim, Tae-Hyung;Kang, Jung-Won;Lee, Jun-Young
    • Journal of Power Electronics
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    • 제9권6호
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    • pp.884-891
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    • 2009
  • An address voltage stabilization circuit for the single-side driving (SSD) method for AC plasma display panels (PDP) is proposed. The single-side driving method, which eliminates a common sustaining driver, uses only two electrodes in a three electrode AC PDP structure. The high-impedance (Hi-Z) mode operation of the data drive ICs during the sustaining period is needed for surface gas-discharge without misfiring in the SSD method but it produces the problem that the address voltage increases up to the breakdown voltage. The proposed circuit based on a flyback converter can stabilize the address voltage under the breakdown voltage and provide better surface gas-discharge performance without any misfiring in the SSD scheme.

PWM 인버터 시스템에서의 전도노이즈 저감을 위한 출력필터 설계에 관한 연구 (Output Filter Design for Conducted EMI Reduction of PWM Inverter-Fed AC Motor Drive System)

  • 김이훈;박규현;원충연;김영석;최세완
    • 전력전자학회논문지
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    • 제6권6호
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    • pp.546-555
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    • 2001
  • 본 논문에서는 PWM 인버터-유도전동기 구동시스템의 전도노이즈 저감을 위한 출력필터 설계에 관한 연구를 수행하였다. 전도노이즈는 고전압 입력, 고용량 구동시스템 그리고 긴 전동기 터미널 등의경우에서 크게 문제가 된다. 고압력을 갖는 시스템에서는 높은 압력에 비례한 직류 링크 전압을 갖고 이에 따라 스위칭 dv/dt가 순간 최대 CM 접지전류를 발생시킨다. 그러므로 이에 대한 대책이 필요하다. 따라서 최근 산업 현장에서 많이 사용되고 있는 PWM 인버터를 설계 제작하여 유도전동기를 구동하고 이에 따라 발생되는 전도노이즈 성분을 감쇠 시킬 수 있는 출력필터를 설계하였고 제작 및 실험을 통하여 그 타당성을 입증하였다.

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A comprehensive analysis on the discretization method of the equation of motion in piezoelectrically actuated microbeams

  • Zamanian, M.;Rezaei, H.;Hadilu, M.;Hosseini, S.A.A.
    • Smart Structures and Systems
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    • 제16권5호
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    • pp.891-918
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    • 2015
  • In many of microdevices a part of a microbeam is covered by a piezoelectric layer. Depend on the application a DC or AC voltage is applied between upper and lower side of the piezoelectric layer. A common method in many of previous works for evaluating the response of these structures is discretizing by Galerkin method. In these works often single mode shape of a uniform microbeam i.e. the microbeam without piezoelectric layer has been used as comparison function, and so the convergence of the solution has not been verified. In this paper the Galerkin method is used for discretization, and a comprehensive analysis on the convergence of solution of equation that is discretized using this comparison function is studied for both clamped-clamped and clamped-free microbeams. The static and dynamic solution resulted from Galerkin method is compared to the modal expansion solution. In addition the static solution is compared to an exact solution. It is denoted that the required numbers of uniform microbeam mode shapes for convergence of static solution due to DC voltage depends on the position and thickness of deposited piezoelectric layer. It is shown that when the clamped-clamped microbeam is coated symmetrically by piezoelectric layer, then the convergence for static solution may be obtained using only first mode. This result is valid for clamped-free case when it is covered by piezoelectric layer from left clamped side to the right. It is shown that when voltage is AC then the number of required uniform microbeam shape mode for convergence is much more than the number of required mode in modal expansion due to the dynamic effect of piezoelectric layer. This difference increases by increasing the piezoelectric thickness, the closeness of the excitation frequency to natural frequency and decreasing the damping coefficient. This condition is often indefeasible in microresonator system. It is concluded that discreitizing the equation of motion using one mode shape of uniform microbeam as comparison function in many of previous works causes considerable errors.

저감된 DC Link Capacitor 부피를 가지는 역률 개선 Valley-Fill Flyback 컨버터의 설계 및 구현 (Practical Design and Implementation of a Power Factor Correction Valley-Fill Flyback Converter with Reduced DC Link Capacitor Volume)

  • 김세민;강경수;공성재;유혜미;노정욱
    • 전력전자학회논문지
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    • 제22권4호
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    • pp.277-284
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    • 2017
  • For passive power factor correction, the valley fill circuit approach is attractive for low power applications because of low cost, high efficiency, and simple circuit design. However, to vouch for the product quality, two dc-link capacitors in the valley fill circuit should be selected to withstand the peak rectified ac input voltage. The common mode (CM) and differential mode (DM) choke should be used to suppress the electromagnetic interference (EMI) noise, thereby resulting in large size volume product. This paper presents the practical design and implementation of a valley fill flyback converter with reduced dc link capacitors and EMI magnetic volumes. By using the proposed over voltage protection circuit, dc-link capacitors in the valley fill circuit can be selected to withstand half the peak rectified ac input voltage, and the proposed CM/DM choke can be successfully adopted. The proposed circuit effectiveness is shown by simulation and experimentally verified by a 78W prototype.

유전율 이방성의 음인 액정을 이용한 Fringe-Field Switching mode의 cell gap 변화에 따른 전기광학 특성 (Cell Gap Dependent Electrode-Optic Characteristics of Fringe-Field Switching Mode using a Liquid Crystal with Negative Dielectric Anisotropy)

  • 정송희;김향율;이종문;이승희
    • 한국전기전자재료학회논문지
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    • 제16권10호
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    • pp.914-922
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    • 2003
  • The FFS (fringe-field switching) mode was known to exhibit both a wide viewing angle and high transmittance, especially when using a liquid crystal with negative dielectric anisotropy. We have studied cell gap-dependent electrode-optic characteristics of the FFS mode using the LC with negative dielectric anisotropy. In case of a small cell gap of 2 ${\mu}$m, the transmittance at the center of pixel and common electrodes is relatively low because effect of surface anchoring that holds the LC to the initial state is larger than that in a large cell gap of 4 .urn such that the LCs in those regions cannot rotate enough. However, in case of a large cell gap of 4 .urn, the effect of surface anchoring becomes relatively small so that the LCs at the center of pixel and common electrode can be twisted enough by applied voltage, giving rise to high transmittance. Therefore, we can conclude that the light efficiency is dependent on the cell gap.

중성점을 사용하지 않는 BLDC 전동기 센서리스 제어 기법 (Sensorless Control Method of the BLDC Motor Without Neutral Point)

  • 심광렬;안정렬
    • 전기학회논문지P
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    • 제61권3호
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    • pp.111-115
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    • 2012
  • Generally, brushless DC motor(BLDCM) driving system uses hall sensors or encoders as the mechanical position or speed sensor. It is necessary to achieve the informations of rotor position for driving trapezoidal type brushless DC motor without any position sensor. In this paper, the commutation signals are obtained without the motor neutral voltage, multistage analog filters, A/D converters, or the complex digital phase shift circuits which are indispensable in the conventional sensorless control algorithms. In the proposed method, in stead of detecting the zero crossing point of the nonexcited motor back electromagnetic force for the average motor terminal to neutral voltage, the commutation signal are extracted directly from the specific average line to line voltage with low-pass filter, adder and comparators circuit. In contrast to conventional methods, the neutral voltage is not need; therefore, the commutation signals are insensitive to the common mode noise. Moreover, the complex phase shift circuit can be eliminated. The effectiveness of the proposed method is verified through simulation results.

저전압 CMOS Gm-C 연속시간 필터 설계 (The Design of Low Voltage CMOS Gm-C Continuous-Time Filter)

  • 윤창훈;정상훈;최석우
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 합동 추계학술대회 논문집 정보 및 제어부문
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    • pp.348-351
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    • 2001
  • In this paper, the Gm-C filter for low voltage and low power applications using a fully-differential transconductor is presented. The designed transconductor using the series composite transistors and the low voltage composite transistors has wide input range at low supply voltage. A negative resistor load (NRL) technology for high DC gain of the transconductor is employed with a common mode feedback(CMFB). As a design example, the third-order Elliptic lowpass filter is designed. The designed filter is simulated and examined by HSPICE using TSMC $0.35{\mu}m$ CMOS n-well parameters. The simulation results show 138kHz cutoff frequency and 11.05mW power dissipation with a 3.3V supply voltage.

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Floating Inverter Amplifiers with Enhanced Voltage Gains Employing Cross-Coupled Body Biasing

  • Jae Hoon Shim
    • 센서학회지
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    • 제33권1호
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    • pp.12-17
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    • 2024
  • Floating inverter amplifiers (FIAs) have recently garnered considerable attention owing to their high energy efficiency and inherent resilience to input common-mode voltages and process-voltage-temperature variations. Since the voltage gain of a simple FIA is low, it is typically cascaded or cascoded to achieve a higher voltage gain. However, cascading poses stability concerns in closed-loop applications, while cascoding limits the output swing. This study introduces a gain-enhanced FIA that features cross-coupled body biasing. Through simulations, it is demonstrated that the proposed FIA designed using a 28-nm complementary metal-oxide-semiconductor technology with a 1-V power supply can achieve a high voltage gain (> 90 dB) suitable for dynamic open-loop applications. The proposed FIA can also be used as a closed-loop amplifier by adjusting the amount of positive feedback due to the cross-coupled body biasing. The capability of achieving a high gain with minimum-length devices makes the proposed FIA a promising candidate for low-power, high-speed sensor interface systems.

MMC 시스템에서의 지령변조 방법에 따른 커먼모드 전압의 발생과 저감 기법 연구 (A Study of Common Mode Voltage Generation according to Modulation Methods and Reduction Strategies on MMC System)

  • 서인교;;박창환;김장목
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2017년도 추계학술대회
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    • pp.9-10
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    • 2017
  • 본 논문은 MMC 토플로지에서 EMI 노이즈와 누설 전류를 발생시키는 커먼모드 전압(Commom Mode Voltage, CMV)을 스위칭 스테이트 해석을 통해 일반화 하고 이를 저감할 수 있는 기법을 제안한다. 이러한 CMV에 관한 해석과 저감 기법은 시뮬레이션으로 타당성을 검증하였다.

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