• Title, Summary, Keyword: Harmonic analysis

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Development of Measurement System for Harmonic Analysis of Electric Equipment (전기설비의 고조파 분석을 위한 측정 시스템의 개발)

  • Yoo, Jae-Geun;Lee, Sang-Ik;Jeon, Jeong-Chay
    • Proceedings of the KIEE Conference
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    • pp.259-261
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    • 2002
  • Recently, according to the spread of semiconductor applied technology like motor speed control contrivance, power conversion installation and so on, harmonic ingredients occurred in switching operation flow into a distribution system and increase voltage distortion of distribution system and bring on obstacles like damage, lowering of capability, false operation and so on of various electrical installation. So, in order to consider a countermeasure to limit occurrence quantity of harmonic source, harmonic interception and others, precision measurement and analysis on voltage, current, power, power factor, the each ingredient of harmonic order, the percentage of total harmonic distortion and so forth are needed. In this paper monitoring system to measure and analyze power quality connected with power harmonics was developed and it's performance is verified by measuring and analyzing three-phase voltage and current of R, S, T in the three-phase and four-wire system using the developed measurement system.

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A Study on the Harmonic Analysis of an Electronic Ballast (전자식 안정기의 고조파 저감 대책)

  • Choi, Hong-Kyu;Hong, Sun-Suk;Oh, Jung-Suk;Yoo, Tae-Kun
    • Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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    • pp.121-127
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    • 2004
  • Electric ballast is widely used to turn on the fluorescent. Electric ballast measure occurrence of harmonic through the actual measurement and it is simulated by modeling equivalent circuit for harmonic analysis. The purpose of this paper is to give an equivalent circuit modeling methodology for the harmonic currents generated by single-phase personal computer loads to evaluate a commercially available series resonant filter for the harmonic currents compensation based on the IEC std 61000-3-2 and IEEE 519 standards for limiting harmonic distortion.

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Analysis of the Harmonic Resonance of Primary Restorative Transmission System Using PSCAD/EMTDC PART II (PSCADI/EMTDC를 이용한 시송전계통의 고조파 공진현상 분석 II)

  • Lee H. J.;Yoo W. K.;Lee K. S.;Park S. M.
    • Proceedings of the KIEE Conference
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    • pp.48-50
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    • 2004
  • The energization of high voltage transmission lines and transformers, that is an inevitable process in most countries as the first restorative action for wide-area blackout, may induce overvoltages such as sustained overvoltage, transient overvoltage and harmonic resonant overvoltage. And these may cause damages to power system equipments or failure of surge arresters. The harmonic resonant overvoltage originates in switching operations and nonlinear characteristics of equipments. Actually it is difficult to predict the occurrence of harmonic overvoltage, since they result from nonlinear characteristics of transformers and other equipments. This paper describes the analysis of domestic primary restorative transmission system using PSCAD/EMTDC. The harmonic resonance is verified and the solution to prevent harmonic resonance is proposed in this paper. As a result, the PSCAD/EMTBC simulation showed slightly conflictive results that had been presented by IEEE Power System Restoration Working Group report.

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A Novel Harmonic Identification Algorithm for the Active Power Filters in Non-Ideal Voltage Source Systems

  • Santiprapan, Phonsit;Areerak, Kongpol;Areerak, Kongpan
    • Journal of Power Electronics
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    • v.17 no.6
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    • pp.1637-1649
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    • 2017
  • This paper describes an intensive analysis of a harmonic identification algorithm in non-ideal voltages source systems. The dq-axis Fourier with a positive sequence voltage detector (DQFP) is a novel harmonic identification algorithm for active power filters. A compensating current control system based on repetitive control is presented. A design and stability analysis of the proposed current control are also given. The aim of the paper is to achieve a robustness of the harmonic identification in a distorted and unbalanced voltage source. The proposed ideas are supported by a hardware in the loop technique based on a $eZdsp^{TM}$ F28335 and the Simulink program. The obtained results are presented to demonstrate the performance of the harmonic identification and the control strategy for the active power filter in non-ideal systems.

The comparison between the prosodic and harmonic aspects: Stress shift (운율 측면과 조화이론 측면의 비교: 강세 현상에 대해)

  • Oh, Kwan-Young
    • English Language & Literature Teaching
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    • v.7 no.2
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    • pp.147-166
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    • 2002
  • The purpose of this paper is to explain stress shift and its following segmental variations when some suffixes are added to the bases. In the past those were analyzed in stress or vowel laxing phenomenon separately, but rather those should be analyzed in one framework compositively. Therefore in this paper I will introduce a new theory, which is known as Harmonic theory, and confirm that it can solve the problems related with stress and vowel laxing simultaneously. The first thing, as a prosodic approach I am going to analyze vowel laxing according to Liberman & Prince (1977), Burzio (1993), and then next to go to the Harmonic theory approach. Within the theory I will analyze the phonological phenomena harmoniously through the important three levels, M-level, W-level, P-level. Therefore this paper is to show that from the comparison between the prosodic analysis and the Harmonic analysis, what is more natural and harmonious analysis is based on the Harmonic approach.

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Analysis of Static Characteristics of PMLSM Using Space Harmonic Analysis Considering Slot Structure (공간고조파법을 이용한 영구자석 선형 동기전동기의 슬롯을 고려한 정특성 해석)

  • Im, Gi-Chae;Hong, Jeong-Pyo;Kim, Gyu-Tak
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.48 no.4
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    • pp.145-151
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    • 1999
  • This paper presents the characteristic analysis method of PMLSM based on the Space Harmonic Analysis method considering the effect of stator slots. The magnetic field for unslotted primary can be easily calculated by the conventional space harmonic analysis method and the resultant magnetic field including slot effect is obtained using the concept of the virtual Equivalent Magnetizing Current(EMC) on primary core. And the influence of space harmonics in airgap flux density and static thrust due to slots is evaluated. In this paper, the results of the analytical method are compared with not only the experimental ones but ones of FEM to verify the validity of the proposed method.

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Real-Time Harmonic Parameters Analyzer for Evaluating Induction Motor Drive System (유도전동기 구동시스템 평가를 위한 실시간 고조피 파라미터 분석장치)

  • Lim, Young-Cheol;Jung, Young-Gook
    • Proceedings of the KIEE Conference
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    • pp.479-483
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    • 1997
  • In general, motor parameters can be divided into mechanical/electrical parameters and harmonic parameters. Mechanical/electrical parameters identification of motor have been studying systematically for a long time. But, systematical study on harmonic parameters analysis for efficient motor drive system are very poor. The goal of this paper is to propose analyzing method of harmonic parameters for motor drive system with various experimental graphic screens and numerical results and to develope harmonic parameters analyzer. A developed analyzer is made up 586-PC and DSP (digital signal processor) board, motor drive system, power and harmonic parameters analyzing software for windows. Harmonic parameters are analyzed using correlation signal processing techniques based on the correlation between voltage and current waveforms. Analysis results are visualized by 3-D current coordinates, and it is compared and evaluated with conventional time/frequency domain. To verify the validity of the proposed system, 1/4HP capacitor run type single phase induction motor and thyristor speed controller is used for analyzing. Harmonic parameters of motor drive system is analyzed and verified, with varying fire angle of thyristor speed controller, and the proposed approach is to confirm validity.

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Ac Hysteresis Loop Depending on the Phase Angle of the Higher Harmonic Induction

  • derac Son;Eun Kyoung Kim
    • Journal of Magnetics
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    • v.1 no.2
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    • pp.90-93
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    • 1996
  • For the design of high efficiency electric machines, analysis of higher harmonic frequency components of the magnetic induction is necessary. We have measured ac magnetic properties of non-oriented silicon steel under harmonic frequencies ranging from $3^rd$ (180 Hz) to $9^th$(540 Hz) and harmonic amplitude components from 10% to 50% of the total amplitude ($B_max$=1.5T). From the experiment, it is found that, if the magnetic induction waveform has above $9^th$ harmonic frequency components of the magnetic induction, the core losses only depended on the harmonic amplitude component, but if harmonic frequency becomes lower than 9th harmonic frequency, the core losses depend on the phase angle and the harmonic amplitude, and phase angle should be considered in the design of electric machine.

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Estimation of Harmonics on Power System of AC Electric Railway (교류 전기철도 전력계통의 고조파 예측량 계산)

  • 송진호;황유모
    • The Transactions of the Korean Institute of Electrical Engineers B
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    • v.52 no.2
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    • pp.68-79
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    • 2003
  • We estimated harmonics on power system of AC railway based on quantitatively measured harmonics and investigated the need of facilities for harmonics reduction. In order to analysis harmonics which inflow into power system due to increase in collector voltages and harmonic currents generated from the train when the railway is in operation, the railway system Is sectioned into power supply, railway line, AT, sectioning Post and subsectioning post. For analysis of extension of currents resulting from the railway loads, PWM converter, VVVF inverter and the feeder system are modeled based on the dynamic node technique(DNT). In order to test the usefulness of the DNT for analysis of harmonic effects, the measured harmonic currents and harmonic magnification ratios at the S/K substation are compared with simulation results using DNT modelling, which include the results for two cases with and without filters for suppression of harmonic currents. When 8 cars(4M4T) are in operation, the total sum of harmonic currents resulting from the train at M and T phases, which inflow into the substation along with the railway line, is calculated. Using the harmonics analysis program for railway feeder system with these data, the total harmonic distortion factor(710) at the outgoing point of KEPCO substation is computed. The calculation shows that when the maximum THD at the receiving point of H/K substation was 0.0443% which is much lower than 1.5% which is the allowable value of KEPCO at 154kV as well as IEEE-519 above 132kV This result indicates that any measure for harmonics reduction in Incheon International Airport Railway is not needed.

Harmonic Analysis and Filter Design on Distribution System using SuperHarm (배전계통에서의 SuperHarm을 이용한 고조파.분석 및 필터 설계)

  • 이종포;김철환
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.14 no.5
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    • pp.36-42
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    • 2000
  • The increasing application of power electronic equipment 'especially (ASDs: adjustable speed drives)] on distribution systems has led to a growing concern for harmonic distortion and the resulting impacts on system equipment and operations. Therefore, harmonic studies have become an important aspect of power system analysis and design in recently years. Computer simulations which is related harmonic are used to quantify the distortion in voltage waveforms in a power system. Many digital computer programs are available for harmonic analysis. In frequency spectrum analysis, Simulation using SuperHarm program is superior to simulation using others. Therefore, Computer simulation using SuperHarm program is one of the effective ways to assess the harmonic effects of ASDs. The purpose of this study is to calculate the quantity of harmonic voltage by varying the ASD side load and to design the optimal harmonic filter for the elimination of harmonics.

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