• Title, Summary, Keyword: Harmonic analysis

Search Result 1,597, Processing Time 0.036 seconds

GIC 적용 대역통과필터를 이용한 컴퓨터 부하의 직렬 아크고장 전류 우수고조파 분석 (Even Harmonic Analysis of Series Arc-fault Current Using BPF of GIC Application in Computer)

  • 고원식;문원식;방선배;김재철
    • 전기학회논문지
    • /
    • v.61 no.10
    • /
    • pp.1554-1560
    • /
    • 2012
  • In this paper, the even harmonic current(2nd, 4th, 6th, 8th) of the arc fault current and normal current were measured in computer load and analyzed. The BPF with GIC was developed to detection of harmonic, the exact center frequency and a high degree of sharpness could be easily obtained. The total even harmonic distortion due to series arc fault in computer load was 31.2%, this value was increased 3.9 times better than the total even harmonic distortion of normal current. The results of analysis of arc fault current RMS variation rate and Peak variation rate per half-cycle, The RMS average variation rate are as follows ; the 2nd harmonic was 0.24, the 4th harmonic was 0.15, the 6th harmonic was 0.19, the 8th harmonic was 0.25, respectively. The Peak average variation rate are as follows ; the 2nd harmonic was 0.19, the 4th harmonic was 0.12, the 6th harmonic was 0.13, the 8th harmonic was 0.15, respectively. The results of this analysis utilize data to detect of series arc fault on wiring of computer load.

제철소 154KV계통 고조파해석 (Harmonic Analysis of 154KV System in Kwangyang Steel Works)

  • 김정하;민호준;강영갑;한무호
    • 대한전기학회:학술대회논문집
    • /
    • /
    • pp.26-28
    • /
    • 2001
  • This paper discussed for harmonic analysis of 154kv system in Kwangyang steel works. The harmonic modelings are developed by harmonic measurement for scores of days in a 154kv substation at a same time. In this paper, the measurement values of harmonic are compared to the analysis results in incoming line. Case studies are presented to predict harmonic distortion of the future system.

  • PDF

Subband PRI 분석 알고리즘 (Subband PRI analysis algorithm)

  • 윤원식
    • 한국통신학회논문지
    • /
    • v.21 no.6
    • /
    • pp.1425-1429
    • /
    • 1996
  • 누락펄스가 발생할 시 PRI 분석을 위한 전형적인 sequence search 알고리즘은 harmonic 문제를 발생시킨다. 본 논문에서 이러한 harmonic 문제를 해결할 수 있는 PRI 분석 알고리즘을 제안한다. 분석해야 할 전체 PRI 범위를 harmonic이 없도록 subband 로 나눈 후, sequence search를 forward 및 backward로 행한다. 전형적인 sequence search 알고리즘에 비하여 제안한 알고리즘의 성능이 증대된다.

  • PDF

고조파 전원발생장치의 제어기 설계 및 개발 (Design and Development of Harmonic Power Source Control Module)

  • 이상익;유재근;전정채;전현재;허혜성;최규하
    • 전력전자학회:학술대회논문집
    • /
    • /
    • pp.40-42
    • /
    • 2007
  • Recently the harmonic generation has deteriorated the quality of electricity and affected the performance on the electrical installation including personal computer, fax, community devices and so on. Some studies of harmonic affects in diagnosis and the cause of accident has not done by the experimental data of harmonic source but merely by presumption according to qualitative analysis. So, in order to research the harmonic affect on the electrical installation according to quantitative analysis and gather reliable data over and over again, it is necessary to develop an Harmonic power source which is capable of generating some harmonics. In this paper, we described about realization of Harmonic power source control module which can produce and added harmonics for the analysis due to harmonic effects.

  • PDF

배전용 변압기의 실시간 고조파 분석 알고리즘 개발 (The Development of Real-Time Harmonic Analysis Algorithm in Distribution Transformer)

  • 박철우
    • 조명전기설비학회논문지
    • /
    • v.27 no.3
    • /
    • pp.43-49
    • /
    • 2013
  • Recently harmonics flowing into power system is increasing as the usage of semiconductor equipments and switching mode power equipments are increasing. Harmonics cause problems such as heat increasing and reduction in capacity of transformers, especially the harmonics flowing into a distribution transformer can lead to the lifetime reduction of transformer. In this paper, we are about to develop a device that can monitor harmonics in real-time as it is affixed to a distribution transformer. Unlike the existing expensive harmonic analysis device, a new harmonic analysis algorithm is proposed in order to implement low-cost equipment. The real-time harmonic analysis algorithm proposed in this paper allows implementation on low performance microcontrollers, thus it can monitor the harmonic in real-time as it is individually affixed to the transformer. Therefore, it would improve the reliability of the transformer and stable power system operation would be possible as it can prevent the transformer accidents in advance.

배전시스템 고조파 모델링에 관한 연구 (Harmonics Modelling for Distribution System)

  • 한형주;왕용필;정형환;성병화;박희철;박인표
    • 대한전기학회:학술대회논문집
    • /
    • /
    • pp.205-207
    • /
    • 2005
  • In this paper, the Point of Common Coupling (PCC) is selected to analyze harmonic characteristic of distribution system by IEC 61000 - 3 - 6 in Electromagnetic Compatibility(EMC). Harmonic voltage and current were measured at the PCC of real distribution system. Harmonic distribution, nonlinear load component and Total Harmonic Distortion(THD) were verified by measurement. The effective and accurate modelling of real distribution system were proved through a analysis of harmonic impedance, voltage and current in steady-state. Harmonic transfer characteristic in distribution system were summarized and investigated through a analysis of harmonic voltage and harmonic current in harmonic current source.

  • PDF

비선형 부하 이차 고조파 발생 실증사례 분석 및 임피던스 변동 기법을 통한 이차 고조파 저감 기법 (Case Study of Second Harmonic Generation under Nonlinear Load and Second Harmonic Elimination Method Based on Impedance Variation Scheme)

  • 방희균;김시경
    • 전기학회논문지
    • /
    • v.62 no.5
    • /
    • pp.604-611
    • /
    • 2013
  • This paper presents an second harmonic elimination method based on the impedance variation scheme. Through the power quality analysis from the nonlinear loads connected on the power system, the second harmonic problems have been analyzed with a case study analysis and the experiments. In the paper, the second Harmonic generation was simulated with a single phase SCR rectifier and the analytical model is proposed for the second harmonic generation. A novel impedance variation scheme is proposed and analyzed to eliminate the second harmonic. The experiment has been performed on the 60(MVA) industry manufacturing plant. The experimental result demonstrates the proposed impedance variation scheme successfully operate on the 60(MVA) industry manufacturing plant.

Harmonic analysis of moderately thick symmetric cross-ply laminated composite plate using FEM

  • Narwariya, Manoj;Choudhury, Achintya;Sharma, Avadesh K.
    • Advances in Computational Design
    • /
    • v.3 no.2
    • /
    • pp.113-132
    • /
    • 2018
  • This paper presents the vibration and harmonic analysis of orthotropic laminated composite plate. The response of plate is determined using Finite Element Method. The eight noded shell 281 elements are used to analyze the orthotropic plates and results are obtained so that the right choice can be made in applications such as aircrafts, rockets, missiles, etc. to reduce the vibration amplitudes. Initially the model response for orthotropic plate and harmonic response for isotropic plate is verified with the available literature. The results are in good agreement with the available literature. Numerical results for the natural frequency and harmonic response amplitude are presented. Effects of boundary conditions, thickness to width ratio and number of layers on natural frequency and harmonic response of the orthographic plates are also investigated. The natural frequency, mode shape and harmonic analysis of laminated composite plate has been determined using finite element package ANSYS.

Method Based on Sparse Signal Decomposition for Harmonic and Inter-harmonic Analysis of Power System

  • Chen, Lei;Zheng, Dezhong;Chen, Shuang;Han, Baoru
    • Journal of Electrical Engineering and Technology
    • /
    • v.12 no.2
    • /
    • pp.559-568
    • /
    • 2017
  • Harmonic/inter-harmonic detection and analysis is an important issue in power system signal processing. This paper proposes a fast algorithm based on matching pursuit (MP) sparse signal decomposition, which can be employed to extract the harmonic or inter-harmonic components of a distorted electric voltage/current signal. In the MP iterations, the method extracts harmonic/inter-harmonic components in order according to the spectrum peak. The Fast Fourier Transform (FFT) and nonlinear optimization techniques are used in the decomposition to realize fast and accurate estimation of the parameters. First, the frequency estimation value corresponding to the maxim spectrum peak in the present residual is obtained, and the phase corresponding to this frequency is searched in discrete sinusoids dictionary. Then the frequency and phase estimations are taken as initial values of the unknown parameters for Nelder-Mead to acquire the optimized parameters. Finally, the duration time of the disturbance is determined by comparing the inner products, and the amplitude is achieved according to the matching expression of the harmonic or inter-harmonic. Simulations and actual signal tests are performed to illustrate the effectiveness and feasibility of the proposed method.

ABSTRACT HARMONIC ANALYSIS OVER SPACES OF COMPLEX MEASURES ON HOMOGENEOUS SPACES OF COMPACT GROUPS

  • Farashahi, Arash Ghaani
    • 대한수학회보
    • /
    • v.54 no.4
    • /
    • pp.1229-1240
    • /
    • 2017
  • This paper presents a systematic study of the abstract harmonic analysis over spaces of complex measures on homogeneous spaces of compact groups. Let G be a compact group and H be a closed subgroup of G. Then we study abstract harmonic analysis of complex measures over the left coset space G/H.