• Title/Summary/Keyword: PWM filter

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An Active Power Filter For Railway Application (전철 적용을 위한 능동필터)

  • Kim Hyeong-Jun;Song Joong-Ho
    • Proceedings of the KSR Conference
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    • 2004.10a
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    • pp.1341-1346
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    • 2004
  • Basic design for single-phase active power filter, which aims at railway applications provided with PWM-controlled converters, is comprehensively studided and its performance is presented in this paper, Active power filters are used to compensate railway signaling and public telecommunication interference due to the high-order harmonic currents generated in railway traction locomotives. A type of hybrid digital filter which is composed of low pass filter and high pass filter is proposed so that the desired harmonic reference current with accurate magnitude and phase shift can be extracted from catenary line current. A design criteria to determine input inductor L and output capacitor C is also described, considering voltage, current. PWM pattern, and switching frequency of the main converters, Finally, computer simulation and DSP-based experiments resulted from laboratory test are presented.

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Low-cost Single-Phase HAIf-bridge Active Power Filter with One Current Sensor (단일 전류센서를 갖는 저가의 단상 반브릿지 APF)

  • 김길동;신정렬;이우동;박현준;김희중
    • Journal of the Korean Society for Railway
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    • v.7 no.3
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    • pp.173-179
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    • 2004
  • This paper describes a low-cost single-phase active power filter, which consists of a half-bridge PWM inverter with a simple control circuit. In order to verify the performance of proposed active power filter, many computer simulations with EMTP codes and experimental works with a hardware prototype were done. Both results confirm that the proposed active power filter shows excellent performance to eliminate the harmonics generated in the single-phase non-linear load. The active power filter has advantage of low implementation cost and compact size, using a half-bridge inverter and a simple control circuit with only one current sensor. So, it can be fabricated as a plug-in type. This paper shows the necessity and a good possibility to apply such advantage to the electric railway system.

Voltage Distortion Approach for Output Filter Design for Off-Grid and Grid-Connected PWM Inverters

  • Husev, Oleksandr;Chub, Andrii;Romero-Cadaval, Enrique;Roncero-Clemente, Carlos;Vinnikov, Dmitri
    • Journal of Power Electronics
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    • v.15 no.1
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    • pp.278-287
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    • 2015
  • This paper proposes a novel voltage distortion approach for output filter design based on the voltage transfer function for both off-grid and grid-connected Pulse Width Modulation (PWM) Inverters. The method explained in detail is compared to conventional methods. A comparative analysis is performed on an example of L and LCL-filter design. Simulation and experimental results for the off-grid and the grid-connected single phase inverter prove our theoretical predictions. It was found that conventional methods define redundant values of the output filter elements. Assumptions and limitations of the proposed approach are also discussed.

An Improved Multi-Tuned Filter for High Power Photovoltaic Grid-Connected Converters Based on Digital Control

  • Sun, Guangyu;Li, Yongli;Jin, Wei
    • Journal of Power Electronics
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    • v.18 no.1
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    • pp.160-170
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    • 2018
  • For high power photovoltaic (PV) grid-connected converters, high order filters such as multi-tuned filters and Traps+RC filters with outstanding filtering performance have been widely researched. In this paper, the optimization of a multi-tuned filter with a low damping resistance and research on its corresponding control scheme have been combined to improve the performance of the proposed filter. Based on the characteristics of the switching harmonics produced by PWM, the proposed filter is optimized to further improve its filtering performance. When compared with the more common Traps+RC filter, the advantages of the proposed filter with low damping resistances in attenuating the major switching harmonics have been demonstrated. In addition, a simpler topology and reduced power loss can be achieved. On the other hand, to make the implementation of the proposed filter possible, on the base of the unique frequency response characteristic of the proposed filter, a digital single-loop control scheme has been proposed. This scheme is a simple and effective means to suppress the resonance peak caused by a lack of damping. Therefore, a smaller volume, better efficiency of the proposed filter, and easy implementation of the corresponding control scheme can be realized. Finally, the superiority of the proposed filter topology and control scheme is verified in experiments.

A Study on Parallel Operation of PWM Converter for Auxiliary bloc High Speed Train (고속전철 보조전원장치용 PWM 컨버터의 병렬운전에 관한 연구)

  • 송상훈;성재원;김연충;원충연;최종묵;기상우
    • Proceedings of the KIPE Conference
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    • 1999.07a
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    • pp.358-361
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    • 1999
  • In auxiliary block of high speed train power factor correction and harmonics reduction is very important issue for efficient energy transport. The GTO-equipped PWM converter is used for traction untill resently. But the rising power capability of IGBTs resently allows to build IGBT-equipped PWM converter with a considerably increased switching frequency. This paper presents switching pattern, control method, operation mode and tuned filter to reduce dc link voltage ripple for paralleled converter.

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LC filter design for reducing output voltage harmonics (출력 전압 고조파 저감을 위한 LC 필터설계)

  • Han, Dong Yeob;Kim, Sungmin
    • Proceedings of the KIPE Conference
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    • 2020.08a
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    • pp.453-454
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    • 2020
  • 본 논문은 PWM에 의한 전압 고조파를 분석하여 LC 필터를 설계하는 방안을 제안한다. 전압형 인버터는 PWM 방식을 이용하여 출력전압을 합성하며, PWM에 의한 전압 고조파는 직류단 전압, Modulation index, Deadtime 등에 의해서 결정된다. 출력 전압 고조파와 PWM 전압고조파와의 관계를 풀어 LC 필터를 설계한다. 제안된 방법으로 설계된 LC 필터는 시뮬레이션을 통해 설계의 타당성을 확인하였다.

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A Distortionless Digital PWM Implementation by means of a Non-integer delay FIR filtering (소수형 디지털연산 알고리즘을 이용한 디지털 PWM의 고유한 비선형특성의 보상)

  • 정진훈;정동호
    • Proceedings of the IEEK Conference
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    • 2003.07e
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    • pp.2427-2430
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    • 2003
  • A uniformly sampled digital pulse-width modulation adopting a pre-compensation filter scheme for applications in high-resolution digital-to-analog data conversion is described. It is shown that linearization of the intrinsic distortion resulting in uniformly sampled pulse-width modulation can be achieved by using a non-integer delay digital filter embedded within a noise shaping re-quantizer.

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Single Phase PWM Converters with Active Filter Functions Both on AC-Input and DC-Output Sides

  • MATSUI, Mikihiko;KITANO, Tatsuya
    • Proceedings of the KIPE Conference
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    • 1998.10a
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    • pp.258-263
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    • 1998
  • A comparative study of single-phase PWM converters having active filtering functions both on ac-input and dc-output sides have been carried out. Based on the function of the dc-output side active filter, two types of configurations, the RPM (ripple power managing) type and the APM (average power managing) type are compared to show their contrastive characteristics. The prototype system using DSP based control algorithms, i.e. deadbeet current control and voltage sensor-less technique using full-order observer, show the availability of the proposed system.

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A PCM-to-PWM Conversion Technique Employing the Noise Shaping Filter (Noise Shaping filter를 이용한 PCM신호의 PWM신호로의 변환)

  • 김병재;김인철
    • Proceedings of the IEEK Conference
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    • 2002.06d
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    • pp.175-178
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    • 2002
  • 본 논문에서는 디지털 오디오 증폭기의 필수적인 부분인, PCM신호를 PW신호로 변환하는 기법에 대하여 고찰한다. 비교적 낮은 해상도의 PWM 신호로 변환할 때 발생하는 문제점들을 살펴보고, oversampling과 통과 대역에서 잡음을 억제하는 noise shaping을 적용한 기법에 대하여 살펴본다. 본 논문에서는 디지털 오디오 증폭기에 적합한 몇 가지 noise shaping 필터를 소개하고, 그들을 사용하였을 때 오디오 품질을 평가하였다.

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DC-Link Active Power Filter for High-Power Single-Phase PWM Converters

  • Li, Hongbo;Zhang, Kai;Zhao, Hui
    • Journal of Power Electronics
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    • v.12 no.3
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    • pp.458-467
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    • 2012
  • Single phase converters suffer from ripple power pulsating at twice the line frequency. The ripple power is usually absorbed by a bulky capacitor bank and/or a dedicative LC resonant link, resulting in a low power density and a high cost. An alternative solution is using a dc link active power filter (APF) to direct the pulsating power into another energy-storage component. The main dc link filter capacitor can then be reduced substantially. Based on a mainstream dc APF topology, this paper proposed a new control strategy incorporating both dual-loop control and repetitive control. The circuit parameter design is also re-examined from a control point of view. The proposed APF scheme has better control performance, and is more suited for high power applications since it works in CCM and with a low switching frequency.