• Title, Summary, Keyword: Third harmonic

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Optimum Air-Gap Flux Distribution with Third Harmonic Rotor Flux Orientation Adjustment for Five-Phase Induction Motor

  • Kang, Min;Yu, Wenjuan;Wang, Zhengyu;Kong, Wubin;Xiao, Ye
    • Journal of Electrical Engineering and Technology
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    • v.13 no.1
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    • pp.315-325
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    • 2018
  • This paper investigates optimum air-gap flux distribution with third harmonic rotor flux orientation adjustment for five-phase induction motor. The technique of objective is to generate a nearly rectangular air-gap flux, and it improves iron utilization under variation loading conditions. The proportional relations between third harmonic and fundamental plane currents is usually adopted in the conventional method. However, misalignment between fundamental and third harmonic component occurs with variation loading. The iron of stator teeth is saturated due to this misalignment. This problem is solved by third harmonic rotor flux orientation adjustment simultaneously, and direction and amplitude are changed with mechanical load variation. The proposed method ensures that the air-gap flux density is near rectangular for a maximum value from no load to rated load. It is confirmed that the proposed method guarantees complete both planes decoupling with third harmonic flux orientation adjustment. The effectiveness of the proposed technique is validated experimentally.

Direct Vector Control of Induction Motor Using the Third Harmonic Component of the Stator Voltage (고정자 전압의 제3고조파 성분을 이용한 유도전동기의 직접 벡터제어)

  • Jung, Jong-Jin;Kim, Heung-Geun
    • Proceedings of the KIEE Conference
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    • pp.97-99
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    • 1993
  • A direct vector control for induction machine based on determination of the spatial position of the airgap flux from the third harmonic component of the stator phase voltage is presented in this Paper. The relationship between the airgap fundamental flux component and the third harmonic flux component obtained from the stator third harmonic voltage is presented at the end of this paper.

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Third Harmonic Injection Circuit to Eliminate Electrolytic Capacitors in Light-Emitting Diode Drivers

  • Yoo, Jin-Wan;Jung, Kwang-Hyun;Jeon, In-Ung;Park, Chong-Yeun
    • Journal of Electrical Engineering and Technology
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    • v.7 no.3
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    • pp.358-365
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    • 2012
  • A new third harmonic injection circuit for light-emitting diode (LED) drivers is proposed to eliminate electrolytic capacitors and thereby extend the lifetime of LED drivers. When a third harmonic current is injected to the input current of the LED driver, the required capacitance of the driver can be reduced. The proposed circuit can control an injection ratio and has simple circuitry. The synchronous third harmonic is generated by a phase locked loop (PLL), a 1/3 counter, and op-amps and applied to a power factor correction circuit. Thus, the storage capacitor can install film capacitors instead of the electrolytic capacitor. The value of storage capacitance can be reduced to 78% compared to an input power factor of 100%. The proposed circuit is applied to the 80W prototype LED driver to experimentally verify the performances.

Novel Third Harmonic Current Injection Technique for Harmonic Reduction of Controlled Converters

  • Eltamaly, Ali M.
    • Journal of Power Electronics
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    • v.12 no.6
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    • pp.925-934
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    • 2012
  • Three-phase controlled converters have many applications in the utility interfacing of renewable energy sources and adjustable speed drives as a rectifier or inverter. The utility line currents of these converters have a high harmonic distortion, which is more than the harmonic standards. This paper introduces a new technique for circulating the third harmonic currents from the dc-link to the line currents to reduce their harmonic contents. The proposed system uses a single-phase PWM converter to control the angle and amplitude of the injection current for each of the firing angle of a three-phase converter. A detailed analysis is introduced to achieve a relationship between the firing angle of the three-phase controlled converter and the power angle of the PWM converter. In addition, a detailed design for the other injection path components is introduced. A simulation and experimental work is introduced to prove the mathematical derivations. Analysis, simulation and experimental results prove the superiority of the proposed technique.

Third Harmonic Generation of Shear Horizontal Guided Waves Propagation in Plate-like Structures

  • Li, Weibin;Xu, Chunguang;Cho, Younho
    • Journal of the Korean Society for Nondestructive Testing
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    • v.36 no.2
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    • pp.149-154
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    • 2016
  • The use of nonlinear ultrasonics wave has been accepted as a promising tool for monitoring material states related to microstructural changes, as it has improved sensitivity compared to conventional non-destructive testing approaches. In this paper, third harmonic generation of shear horizontal guided waves propagating in an isotropic plate is investigated using the perturbation method and modal analysis approach. An experimental procedure is proposed to detect the third harmonics of shear horizontal guided waves by electromagnetic transducers. The strongly nonlinear response of shear horizontal guided waves is measured. The accumulative growth of relative acoustic nonlinear response with an increase of propagation distance is detected in this investigation. The experimental results agree with the theoretical prediction, and thus providing another indication of the feasibility of using higher harmonic generation of electromagnetic shear horizontal guided waves for material characterization.

A High Performance Harmonic Mixer Using a plastic packaged device

  • Kim, Jae-Hyun;Go, Min-Ho;Park, Hyo-Dal;Shin, Hyun-Sik
    • The Journal of the Korea institute of electronic communication sciences
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    • v.2 no.1
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    • pp.1-9
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    • 2007
  • In this paper, a third-order harmonic mixer is designed using frequency multiplier theory for the Ka-band. The gate bias voltage is selected by frequency multiplier theory to maximize the third-order harmonic element ofthe fundamental LO frequency in the proposed mixer. The designed mixer has a gate mixer structure composed of a gate terminal input for the fundamental local signal ($f_{LO}$), RF signal (${RF}$) and a drain terminal output for the harmonic frequency ($3f_{LO}-f_{RF}$) respectively. The Ka-band harmonic mixer is designed and fabricated using a commercial GaAs MESFET device with a plastic package. The proposed mixer will provide a solution for the problems found in the high cost, complex circuitry in a conventional Ka-band mixer. The 33.5 GHz harmonic mixer has a -10 dB conversion gain by pumping 11.5 GHz LO with a +5 dBm level.

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A Compensation Method of Parameter Variations for the Speed-Sensorless Vector Control System of Induction Motors using Zero Sequence Third Harmonic Voltages (영상분 3고조파 전압을 이용한 속도센서없는 유도전동기 벡터제어 시스템의 파라미터 변동 보상)

  • Choe, Jeong-Su;Kim, Jin-Su;Kim, Yeong-Seok
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.48 no.2
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    • pp.75-82
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    • 1999
  • A compensation method of the motor parameters using zero sequence third harmonic voltage is presented for the speed sensorless vector control of the induction motor considering saturation of the flux. Generally, the air-gap flux of the saturated induction motor contains the space harmonic components rotating with the synchronous frequency of the motor. Because the EMF of the saturated induction motor contains the zero sequence harmonic voltages at the neutral point of the motor, those harmonic voltages can be used as a saturation index. In this work, the rotor flux observer is firstly designed for the speed sensorless vector control of induction motor. And a novel measurement method of the space harmonic voltage and a compensation method of th LPF(Low Pass Filter) are proposed. For compensating the non-linear variations of the magnetizing inductance depending on the saturation level of the motor, the dominant third harmonic voltage of the motor is used as a saturation function of the air-gap flux. And the variation of the stator resistance owing to the motor temperature can also be measured with the phase angle between the impressed voltage vector and the zero sequence voltage. The validity of the proposed parameter compensation scheme in the speed sensorless vector control using rotor flux observer is verified by the result of the simulations and the experiments.

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Second Harmonic Conversion of Nd:YAG Laser using $KH_2PO_4(KDP)$ Crystal ($KH_2PO_4(KDP)$ 결정을 이용한 Nd:YAG 레이저의 제3고조파 변환)

  • Chang, Yong-Moo;Kim, Byung-Tai;Kang, Hyung-Boo
    • Proceedings of the KIEE Conference
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    • pp.633-636
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    • 1989
  • The simulation results of the third harmonic conversion with 1.064 um Nd :YAG laser using polarization mismatch method are reported. The third harmonic conversion efficiency was over 65% for the Gaussian incident pulse of $300{\sim}400MW/cm^2$ peak intensity, and over 80% for $3{\sim}4GW/cm^2$ peak intensity pulse. The dependence of the third harmonic conversion efficiency' on the variation of incident polarization angle ${\theta}_p$ and angular discrepancy ${\Delta}{\theta}$ of phase matched angle ${\theta}_m$ is discussed.

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A Speed Sensorless Vector Control Using the Zero Sequence Third Harmonic Voltages (영상부 3고조파를 이용한 유도전동기의 속도센서없는 벡터제어)

  • 최정수;유완식;김영석
    • Proceedings of the KIPE Conference
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    • pp.388-394
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    • 1998
  • In this paper, we propose a speed sensorless control of the saturated induction motor using the zero sequence third harmonic voltages and a compensation method of the stator resistance variations. The air-gap flux of the saturated induction motor contains the space harmonic components rorating synchronous frequency. As a function of the air-gap flux saturation, the dominant third harmonic voltage is used to compensate the non-linear variations of the mutual inductance depending on the saturation level of the motor. and also the stator resistance variations can be measured with the phase angle between the voltage vector and the zero sequencial voltages. The validity of the proposed compensation scheme in the speed sensorless control using rotor flux observer is verified by simulations.

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Torque Density Improvement of Five-Phase PMSM Drive for Electric Vehicles Applications

  • Zhao, Pinzhi;Yang, Guijie
    • Journal of Power Electronics
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    • v.11 no.4
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    • pp.401-407
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    • 2011
  • In order to enhance torque density of five-phase permanent magnetic synchronous motor with third harmonic injection for electric vehicles (EVs) applications, optimum seeking method for injection ratio of third harmonic was proposed adopting theoretical derivation and finite element analysis method, under the constraint of same amplitude for current and air-gap flux. By five-dimension space vector decomposition, the mathematic model in two orthogonal space plane, $d_1-q_1$ and $d_3-q_3$, was deduced. And the corresponding dual-plane vector control method was accomplished to independently control fundamental and third harmonic currents in each vector plane. A five-phase PMSM prototype with quasi-trapezoidal flux pattern and its fivephase voltage source inverter were designed. Also, the dual-plane vector control was digitized in a single XC3S1200E FPGA. Simulation and experimental results prove that using the proposed optimum seeking method, the torque density of five-phase PMSM is enhanced by 20%, without any increase of power converter capacity, machine size and iron core saturation.