• Title/Summary/Keyword: Harmonics suppression

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The Design of Active Power Filter with the Performance of Harmonic Suppression and Input Power Factor Correction (고조파 저감과 입력역률 개선을 위한 전력용 능동필터의 설계)

  • Park, Hae-Won;Choi, Seong-Kwan;Kim, Ho;Kim, Beung-Jin;Jeon, Hee-Jong
    • Proceedings of the KIEE Conference
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    • 2000.11b
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    • pp.375-377
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    • 2000
  • In this paper, voltage controlled APF(Active Power Filter) is introduced to improve power factor and reduce harmonic generated from nonlinear load. The voltage controlled APF which is consisted of inverter and passive filter operates with nonlinear load simultaneously. According to the results of simulation, it is proved that the proposed system has the performance of improving power factor and reducing harmonics.

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A Load Compensator Based on One-Cycle Control with Plug-In Repetitive Control

  • Hu, Jian;Sun, Zhaohui;Ma, Hao;Chen, Guozhu
    • Journal of Power Electronics
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    • v.15 no.2
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    • pp.443-454
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    • 2015
  • This study proposes a novel one-cycle control scheme with a plug-in repetitive controller for load compensator. The novelty of this scheme lies in the combination of high dynamics and the simplicity of a one-cycle controller and good steady-state harmonic suppression ability of the repetitive controller. In addition, the proposed scheme can reduce the effect of the harmonics in phase voltage for the existence of the repetitive controller. Finally, experimental results on a three-phase, four-wire, three-level load compensator are reported to validate the effectiveness of the proposed control scheme.

Wireless Power Transmission High-gain High-Efficiency DC-AC Converter Using Harmonic Suppression Filter (고조파 억제 필터를 이용한 무선전력전송 고이득 고효율 DC-AC 변환회로)

  • Hwang, Hyun-Wook;Choi, Jae-Won;Seo, Chul-Hun
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.49 no.2
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    • pp.72-75
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    • 2012
  • In this paper, high-efficiency DC-AC converter is implemented for the wireless power transmission. The DC-AC converter is implemented by combining the oscillator and power amplifier. Because the conversion efficiency of wireless power transmitter is strongly affected by the efficiency of power amplifier, the high-efficiency power amplifier is implemented by using the Class-E amplifier structure. Also, because the output power of oscillator connected to the input stage of power amplifier is low, high-gain two-stages power amplifier using the drive amplifier is implemented to realize the high-output power DC-AC converter. The dual band harmonic suppression filter is implemented to suppress 2nd, 3rd harmonics of 13.56 MHz. The output power and conversion efficiency of DC-AC converter are 40 dBm and 80.2 % at the operation frequency of 13.56 MHz.

Suppression of Harmonic Passband of Bandpass Filters(BPFs) Using Parallel-Coupled Mushroom Structure (평행 결합 Mushroom 구조를 이용한 대역 통과 여파기의 고조파 성분 억제)

  • Lee, Jae-Gon;Lee, Jeong-Hae
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.18 no.2 s.117
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    • pp.118-125
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    • 2007
  • Harmonic band of bandpass filter(BPF) is suppressed using coupled mushroom structure. Between double positive (DPS) transmission line such as microstrip and double negative(DNG) transmission line such as one dimensional mushroom structure, strong coupling broadly arises in the cross range of dispersion curves of isolated microstrip and mushroom structure because of complex propagation constant in the cross range. Strong coupling inhibits wave propagation, so that this kind of structure can be utilized as bandstop filter(BSF). This BSF utilizes coupled transmission line instead of coupled resonator, resulting in broad bandwidth(>30 %), shan-rejection, and high rejection level. The strong coupling between DPS and DNG transmissionline makes it possible shorten coupling length, resulting in compact size. In this paper, parallel coupled BSF having center frequency of 4 GHz and 3 dB fractional bandwidth of 40 % is designed and utilized to suppressed spurious mode of two bandpass filters.

Design of 100mW Frequency Tripler Operating at 7 GHz (7 GHz 대역 100 mW 주파수 3체배기의 제작)

  • Roh, Hee-Jung;Joo, Jae-Hyun;Koo, Kyung-Heon
    • Journal of Advanced Navigation Technology
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    • v.14 no.1
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    • pp.20-26
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    • 2010
  • In this paper, a frequency tripler has been designed with 100mW medium-power using P-HEMT. It is designed to obtain 7.2 GHz frequency at the output that is an integer multiple of 2.4 GHz input frequency by using nonlinear device that produces 3rd harmonic. The frequency tripler is designed by using load-pull simulation. To suppress the 2nd and fundamental, notch filter is used for the frequency tripler. The tripler is designed to obtain about 21dBm output power with 15 dBm input, i.e., 6 dB conversion gain and the suppression of 20 dBc at fundamental, and 30 dBc at the second harmonics.

A Resonant Characteristics Analysis and Suppression Strategy for Multiple Parallel Grid-connected Inverters with LCL Filter

  • Sun, Jian-jun;Hu, Wei;Zhou, Hui;Jiang, Yi-ming;Zha, Xiao-ming
    • Journal of Power Electronics
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    • v.16 no.4
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    • pp.1483-1493
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    • 2016
  • Multiple parallel inverters have multiple resonant frequencies that are influenced by many factors. This often results in stability and power quality problems. This paper develops a multiple input multiple output model of grid-connected inverter systems using a closed-loop transfer function. The influence factors of the resonant characteristics are analyzed with the developed model. The analysis results show that the resonant frequency is closely related to the number, type and composition ratio of the parallel inverters. To suppress resonance, a scheme based on virtual impedance is presented, where the virtual impedance is emulated in the vicinity of the resonance frequency. The proposed scheme needs one inverter with virtual impedance control, which reduces the design complexity of the other inverter controllers. Simulation and experimental tests are carried out on two single phase converter-based setups. The results validate the correctness of the model, the analytical results and the resonant suppressing scheme.

A Design of 16-QAM Modulator by use of Direct Digital Frequency Synthesizer (디지탈 직접 주파수 합성기를 이용한 16-QAM 변조기 설계)

  • 유상범;유흥균
    • The Journal of the Acoustical Society of Korea
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    • v.18 no.5
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    • pp.52-57
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    • 1999
  • It is very important to design of QAM modulator of high spectral efficiency for high speed data transmission. In this paper, typical 16-QAM modulator is designed by modification design of DDFS(direct digital frequency synthesizer). DDFS generates sinusoidal waveform digitally to the frequency setting word. Phase modulation is accuratly made by control of a generated phase increment value and amplitude modulation is accomplished in the D/A converter output by control of amplitude level. For the suppression of harmonics and glitch, dual-structured DDFS is studied to improve the spurious characteristics. P-Spice is used for design and simulation in mixed mode. Also we can get the satisfactory results of designed 16-QAM modulator from the constellation output.

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Harmonic Suppression of the Input Current in Microwave Oven Using LLC Resonant Inverter (전자레인지용 LLC 공진형 인버터의 입력전류 고조파 억제)

  • Kang, Kyelyong;Kim, Heung-Geun;Cha, Honnyong
    • The Transactions of the Korean Institute of Power Electronics
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    • v.23 no.3
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    • pp.225-230
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    • 2018
  • This paper proposes a parametric design of an LLC resonant inverter used for a microwave oven. To improve the harmonic performance of the microwave oven, a current controller with a variable PI gain is proposed. Due to the recent strengthening of harmonics regulations, inverter control technology for microwave ovens is now required to satisfy harmonic performance. In an LLC resonant inverter, the voltage gain varies remarkably depending on the magnetron voltage, output power, and input voltage. To satisfy harmonic performance, a controller that can maintain operation in the zero-voltage switching (ZVS) region and control changes in voltage gain is required. The modified design of the LLC resonant inverter ensures ZVS operation even when the magnetron is heated. Application of the variable current controller improves harmonic control according to the instantaneous gain curve change. The validity of the proposed power control with a variable current controller is verified by experiments with a 1200 W microwave oven.

Design and Fabrication of the Frequency Doubler for 24GHz Local Oscillator (24GHz 대역 국부발진기용 주파수 체배기 설계 및 제작)

  • Seo, Gon;Kim, Jang-Gu;Han, Sok-Kyun;Park, Chang-Hyun;Choi, Byung-Hai
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2003.10a
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    • pp.411-415
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    • 2003
  • In this paper, a reflector type frequency doubler for local oscillator at 24GHz is designed and fabricated with ne71300-N MESFET. Optimum source and load impedances are decided through a multiharmonic load pull simulation technique. A conversion gain ran be improved using the reflector and fundamental and third harmonics are well suppressed with open stub of λ/4 length. Measured results show output power at 0dBm of input power is -3.776dBm, conversion gain 0.736dB, harmonic suppression 41.064dBc, respectively.

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A Study on Design of Reflector Type Frequency Doubler in K-Band (리플렉터 형태의 K-대역 주파수 체배기 구현에 관한 연구)

  • Han, Sok-Kyun;Choi, Hyung-Ha
    • Journal of Navigation and Port Research
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    • v.28 no.1
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    • pp.37-41
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    • 2004
  • In this paper, a reflector type frequency doubler for local oscillator at 24GHz is designed and fabricated with ne71300-N MESFET. Optimum source and load impedances are decided through a multiharmonic load pull simulation technique. A conversion gain can be improved using the reflector and fundamental and third harmonics are well suppressed with open stub of $\lambda$/4 length Measured results show output power at 0dBm of input power is -3.776dBm, conversion gain 0.736dB, harmonic suppression 41.064dBc, respectively.