• Title/Summary/Keyword: three-phase PWM inverter

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Design of an LCL-Filter for Grid-Connected Three-Level Inverter System (계통 연계형 3-레벨 인버터 시스템을 위한 LCL-필터 설계 방법)

  • Park, Joon Young;Kim, Seok-Min;Seo, SeungGyu;Park, Seong-Soo;Lee, Kyo-Beum
    • Journal of IKEEE
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    • v.21 no.2
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    • pp.105-114
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    • 2017
  • This paper proposes a design method of an LCL-filter for grid-tied three-level inverter systems. The demand for three-phase PWM inverters in applications such as wind or solar power generation systems has been increase in recent years. To reduce harmonic components caused by switching operation, such inverters are connected to the grid via an LCL filter. Although there are research results for designing LCL-filter, the modulation method should be fully considered to make the filter perform desired cancellation ability with minimized size. This paper presents the design methodology for an LCL-filter that is optimized for SVM switching operations. The simulation and experimental results verify the validity of the LCL-filter designed with proposed method in this paper.

A Novel Random PWM Technique with a Constant Switching Frequency Utilizing an Offset Voltage (옵셋 전압을 이용한 일정 스위칭 주파수의 Random PWM 기법)

  • Kim, Do-Kyeom;Kim, Sang-Hoon
    • The Transactions of the Korean Institute of Power Electronics
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    • v.22 no.1
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    • pp.67-74
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    • 2017
  • This study proposes a novel random pulse-width modulation (PWM) technique with a constant switching frequency utilizing a random offset voltage. The proposed PWM technique spreads switching harmonics by varying the position of an active voltage vector without a switching frequency variation. The implementation of the proposed PWM technique is simple because it does not require additional hardware and complex algorithm. The proposed random PWM technique is compared with the conventional PWM technique on the factors of harmonic spectrum, total harmonic distortion, and harmonic spread factor to confirm the harmonic spread effect. The validity of the proposed method is verified by simulations and experiments on a three-phase inverter drive system.

A Fault Tolerant Structure and Control Strategy for Electromagnetic Stirring Supplies

  • Li, Yan;Luo, An;Xiang, Xinxing;Chen, Yandong;He, Zhixing;Zhou, Fayun;Chen, Zhiyong
    • Journal of Power Electronics
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    • v.17 no.5
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    • pp.1256-1267
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    • 2017
  • A fault tolerant structure and its corresponding control strategy for electromagnetic stirring power supplies are proposed in this paper. The topology structure of the electromagnetic stirring power supply contains two-stages. The fore-stage is the PWM rectifier. The back-stage is the fault tolerant inverter, which is a two-phase three-bridge orthogonal inverter circuit while operating normally. When the power switch devices in the inverter are faulty, the structure of the inverter is reconfigured. The two-phase half bridge inverter circuit is constructed with the remaining power switch devices and DC-link capacitors to keep the system operating after cutting the faulty power switch devices from the system. The corresponding control strategy is proposed to let the system work under both normal and fault conditions. The reliability of the system is improved and the requirement of the electromagnetic stirring process is met. Finally, simulation and experimental results verify the feasibility of the proposed fault tolerant structure and corresponding control strategy.

The Characteristics Analysis of New Dc 48[V] Telecommunication Power System using Forward Type three Phase Rectifier (포워드형 3선 PWM 정류기를 이용한 새로운 DC 48[V] 통신용 전원시스템의 특성 해석)

  • Suh, Ki-Young
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.1
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    • pp.34-40
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    • 2006
  • This paper proposed power system for new DC 49[V] telecommunication using forward three-phase PWM rectifier power factor and efficiency for improvement of ripple voltage. Proposed power system for DC 48[V] telecommunication that consists of power conversion devices including switch, inductor and condenser were made between each line, in power inverter device of each switch control turn-on in period of continuity time control to get power factor '1' of sine wave current and on-off of switch lessens peak current that was happened and got conversion efficiency 92.1[%] composing in PWM rectifier of forward form instead of general PWM rectifier. Also, harmonic input regulation value(IEC61000-3-2 Class-As) satisfy input current and reduce ripple factor of output voltage in state that distortion of three-phase supply is overlapped each other.

The Effect on Patient Dose Reduction with Improvement of the Output Characteristics for Inverter Type X-ray Generator (인버터식 X선발생장치의 출력특성개선이 환자피폭선량 경감에 미치는 효과)

  • Roh, Mo-Eun;Lee, Seong-Kil;Kim, Young-Keun
    • Korean Journal of Digital Imaging in Medicine
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    • v.13 no.1
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    • pp.27-32
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    • 2011
  • The conventional types of X-ray generators were bulky in physical size and heavy in weight, and the control accuracies of the output voltages were not always satisfactory. The high frequency switching inverter and converter technology on power conversion and control systems have been greatly closed up introducing power semiconductor devices. To decreasing the volume and the weight of high voltage transformer, and to stabilize ripple. In this paper, the newly developed x-ray generator in a low cost using duty modulation PWM inverter. This system verify improved performance by stabilize ripple of X-ray tube voltage and compared the reproducibility, linearity and dose in single phase, three phase and PSU.

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Implementation of a High Efficiency Grid-Tied Multi-Level Photovoltaic Power Conditioning System Using Phase Shifted H-Bridge Modules

  • Lee, Jong-Pil;Min, Byung-Duk;Yoo, Dong-Wook
    • Journal of Power Electronics
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    • v.13 no.2
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    • pp.296-303
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    • 2013
  • This paper proposes a high efficiency three-phase cascaded phase shifted H-bridge multi-level inverter without DC/DC converters for grid-tied multi string photovoltaic (PV) applications. The cascaded H-bridge topology is suitable for PV applications since each PV module can act as a separate DC source for each cascaded H-bridge module. The proposed phase shifted H-bridge multi-level topology offers advantages such as operation at a lower switching frequency and a lower current ripple when compared to conventional two level topologies. It is also shown that low ripple sinusoidal current waveforms are generated with a unity power factor. The control algorithm permits the independent control of each DC link voltage with a maximum power point for each string of PV modules. The use of the controller area network (CAN) communication protocol for H-bridge multi-level inverters, along with localized PWM generation and PV voltage regulation are implemented. It is also shown that the expansion and modularization capabilities of the H-bridge modules are improved since the individual inverter modules operate more independently. The proposed topology is implemented for a three phase 240kW multi-level PV power conditioning system (PCS) which has 40kW H-bridge modules. The experimental results show that the proposed topology has good performance.

AC harmonic elimination and reactive power compensation by voltage-type active filter (전압형 능동필터에 의한 교류고조파제거와 무효전력보상)

  • 김한성;최규하;신우석;이제필
    • 제어로봇시스템학회:학술대회논문집
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    • 1988.10a
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    • pp.688-692
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    • 1988
  • The active filter system for harmonic current compensation is presented in this paper. The active filter, composed of a three-phase voltage-type PWM inverter and the capacitor, compensates both the harmonic currents and the reactive power by injecting the PWM current to the ac line. This paper describes the principle of harmonic current compensation, the calculation circuits for the harmonic currents to be injected, the several compensation characteristics. Also the experimental results are shown to verify the theory proposed in this paper.

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Active and Reactive Power Control Method for Grid-Connected Three-Phase PWM Inverter (계통 연계형 3상 PWM 인버터의 유·무효전력제어 방법)

  • Ahn, Hyun-Jin;Jung, Young-Gook;Lim, Young-Cheol;Oh, Seung-Yeol;Kim, Kwang-Heon
    • Proceedings of the KIPE Conference
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    • 2010.11a
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    • pp.263-264
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    • 2010
  • 본 연구에서는 3상 계통 연계형 인버터의 유 무효전력제어를 통해 부하에 필요한 전력을 공급하며 계통과 인버터를 안정적으로 연계하는 방법을 다루고 있다. 부하 변동 및 계통전압과 인버터 전압의 위상차 ${\theta}$에 따라 PSIM 시뮬레이션을 수행하였으며, 타당성을 입증하였다

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Analysis and Design of a Three-Phase Synchronous Solid-state Var Compensator using Neutral-Point-Clamped Inverter (NPC 인버터를 이용한 3상 동기형 SVC의 해석 및 설계)

  • Lim, Su-Saeng;Lee, Eun-Woong;Kim, Sung-Heon;Lee, Dong-Ju
    • Proceedings of the KIEE Conference
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    • 1997.11a
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    • pp.42-45
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    • 1997
  • A synchronous solid-state var compensator(SSVC) system which employs a three-phase neutral-point-darned (NPC) inverter is presented and analyzed for high voltage and high power applications. The proposed SSVC system can compensate for leading and lagging displacement factor. An optimal pulse-width-modulation (PWM) is used as a means of reducing the size of reactive components. A equivalent model is obtained using DQ-transform, and the characteristic of open-loop system are archived from DC and AC analyzes. A $\alpha$ phase-shift control is suggested using a self-controlled dc bus.

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Harmonic Current Compensation based on Three-phase Three-level Shunt Active Filter using Fuzzy Logic Current Controller

  • Salim, Chennai;Benchouia, M.T.;Golea, A.
    • Journal of Electrical Engineering and Technology
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    • v.6 no.5
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    • pp.595-604
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    • 2011
  • A three-phase three-level shunt active filter controlled by fuzzy logic current controller which can compensate current harmonics generated by nonlinear loads is presented. Three-level inverters and fuzzy controllers have been successfully employed in several power electronic applications these past years. To improve the conventional pwm controller performance, a new control scheme based on fuzzy current controller is adopted for three-level (NPC) shunt active filter. The scheme is designed to improve compensation capability of APF by adjusting the current error using a fuzzy rule. The inverter current reference signals required to compensate harmonic currents use the synchronous reference detection method. This technique is easy to implement and achieves good results. To maintain the dc voltage across capacitor constant and reduce inverter losses, a proportional integral voltage controller is used. The simulation of global system control and power circuits is performed using Matlab-Simulink and SimPowerSystem toolbox. The results obtained in transient and steady states under various operating conditions show the effectiveness of the proposed shunt active filter based on fuzzy current controller compared to the conventional scheme.