• Title/Summary/Keyword: parallel coupling lines

Search Result 27, Processing Time 0.045 seconds

A New fault Location Algorithm for 765㎸ Untransposed Parallel Transmission Lines (765㎸ 비연가 송전선로에서 고장점 표정 알고리즘)

  • 안용진;강상희
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.53 no.3
    • /
    • pp.168-174
    • /
    • 2004
  • This paper describes a new fault location algorithm based on the voltage equation at the relaying point using 6-phase current for untransposed 765㎸ parallel transmission lines. The proposed method uses the voltage and current collected at only the local end. By means of 3-phase circuit analysis theory to compensate the mutual coupling effects between parallel lines, the fault location is derived. The fault distance is determined by solving the 2nd distance equation based on KVL(Kirchhoff's Voltage Law). Extensive simulation results using EMTP(Electromagnatic Transients Program) have verified that the error of the fault location achieved is up to 4.56(%) in untransposed parallel transmission lines.

The Design of a Wideband 3 dB Quadrature Coupler using N-Section Parallel-Coupled Lines (N단 평행 결합 선로를 이용한 90° 광대역 3 dB 결합기 설계)

  • 조정훈;윤상원
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.13 no.1
    • /
    • pp.94-100
    • /
    • 2002
  • In this paper, we proposed a 3 dB coupler using N-section parallel-coupled lines and designed a very compact one based on the analysis results. The coupled line has been analyzed by spectral domain method. After we obtain the s-parameters of N-section parallel-coupled lines by using port reduction method 4-port s-parameters are derived. The 3 dB couplers, which were fabricated, are not necessary to implement high impedance lines and tight coupling gaps as Lange Couplers because loose coupling is used. To realize a minimum section, we used the PCB that has high a dielectric constant and a thickness. The experimental results show that it has wide bandwidth of about 42 %(0.5 dB unbalance) from 3.6 GHz to 5.5 GHz and phase difference within 1 degree. Also, The isolation characteristics about 15 dB at its pass-band are obtained.

A New Distance Relaying Algorithm Immune to Mutual Coupling Effect and Reactance Effect for 765kV Untransposed Parallel Transmission Lines (상호결합효과와 리액턴스효과를 제거한 765kV 비연가 송전선로 보호용 거리계전 알고리즘)

  • Ahn Yong-Jin;Kang Sang-Hee
    • The Transactions of the Korean Institute of Electrical Engineers A
    • /
    • v.54 no.1
    • /
    • pp.25-30
    • /
    • 2005
  • An accurate digital distance relaying algorithm which is immune to mutual coupling effect and reactance effect of the fault resistance and the load current for the line faults in 765kV untransposed transmission lines is proposed. The algorithm can estimate adaptively the impedance to a fault point independent of the fault resistance. To compensate the magnitude and phase of the apparent impedance, this algorithm uses the angle of an impedance deviation vector. The impedance correction algorithm for phase-to-ground fault and phase-to-phase short fault use a voltage equation at fault point to compensate the fault current at fault point. A series of tests using EMTP output data in a 765kV untransposed transmission lines have proved the accuracy and effectiveness of the proposed algorithm.

A Study on Compound Technique for Increasing the Bandwidth of Microstrip Antennas using the Paralle Coupled Lines (평행 결합 선로를 이용한 복합 광대역 기법 적용 마이크로스트립 안테나에 관한 연구)

  • 김정일;한만군;윤영중
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.12 no.5
    • /
    • pp.713-721
    • /
    • 2001
  • In this paper, parasitic patches gap-coupled microstrip antenna and stacked microstrip patch antenna combined with parallel coupled lines, which are a kind of wideband impedance matching network, are proposed to get the wider bandwidth. The iterative method using a distributed network is proposed to design the parallel coupled lines as a wideband impedance matching network. Measurements show that the proposed antennas provide wider bandwidths ~1.6 times and ~1.5 times those of conventional parasitic gap-coupled microstrip patch antenna and stacked microstrip patch antenna. In addition, measured radiation patterns show no serious variation of radiation patterns though the parallel coupled lines is added. The antenna gain is, however, lowered about 1 dB and 0.5 dB by the coupling loss in the parallel coupled lines.

  • PDF

Compact Dual-Band Bandpass Filter Using U-Shaped Stepped-Impedance Resonators with Parallel Coupled Structures

  • Sung, Gyuje
    • Journal of electromagnetic engineering and science
    • /
    • v.18 no.2
    • /
    • pp.73-77
    • /
    • 2018
  • This paper proposes a dual-band bandpass filter using stepped-impedance resonators (SIRs) with parallel coupled structures. The proposed filter adopts U-shaped SIRs with parallel coupled lines (PCLs) that have interdigital and comb-line shorted ends. The central PCLs build an upper passband and a transmission zero, and the two U-shaped SIRs build a lower passband. Four resonators and coupling structures are theoretically analyzed to derive its scattering parameters. A novel dual-band bandpass filter is designed and fabricated using the induced scattering characteristics. The measured results show that the fabricated dual-band bandpass filter has an insertion loss of less than 1.02 dB in the lower band of 2.45 GHz and of 3.01 dB in the upper band of 3.42 GHz, and a band-to-band isolation of more than 40 dB, from 3.14 to 3.2 GHz.

Study on the Influence of Distribution Lines to Parallel Inverter Systems Adopting the Droop Control Method

  • Zhang, Xuan;Liu, Jinjun;You, Zhiyuan;Liu, Ting
    • Journal of Power Electronics
    • /
    • v.13 no.4
    • /
    • pp.701-711
    • /
    • 2013
  • This paper takes into account the influence of the different impedances of distribution lines on power distribution among inverters when the inverters are paralleled with the droop control method. The impact of distribution lines on the power distribution of inverters can be divided into two aspects. Firstly, since the distributed generators are in low voltage grids, there is resistive impedance in the distribution lines, which will cause control coupling and reduce system stability. The virtual negative resistive impedance of inverters is adopted in this paper to neutralize the resistive element of distribution lines and thus make the distribution line impedance purely inductive. Secondly, after solving the resistive impedance problem, the difference in the inductive impedance value of distribution lines due to the low density of distributed generators will cause an unequal share of reactive power. With regards to this problem, modification is put forward for the droop control strategy to share the reactive power equally. The feasibility of the design is validated by simulation and experimental results.

A Narrow Bandwidth Microstrip Band-Pass Filter with Symmetrical Frequency Characteristics

  • Jun, Dong-Suk;Lee, Hong-Yeol;Kim, Dong-Young;Lee, Sang-Seok;Nam, Eun-Soo
    • ETRI Journal
    • /
    • v.27 no.5
    • /
    • pp.643-646
    • /
    • 2005
  • This letter proposes a band-pass filter (BPF) with two transmission zeros based on a combination of parallel coupling and end coupling of half-wave transmission lines. The fabricated BPF exhibited a narrow bandwidth and two transmission zeros near the pass-band due to the end-coupled and shielding waveguide. At the center operation frequency of 60 GHz, the 20 dB bandwidth of the BPF is 1.0 GHz, which is almost 2% of the center operation frequency, and the insertion loss is 3.12 dB. Two transmission zeros reach approximately 40 dB at 58.5 and 62.5 GHz. The simulation results almost agree with the measured results.

  • PDF

Numerical Analysis of Multi-Layer Multi-Coupled Microstrip Lines (쉬해석에 의한 다층 다중 결합 마이크로스트립 선로 해석)

  • Seo, Cheol-Heon
    • The Journal of the Acoustical Society of Korea
    • /
    • v.13 no.1E
    • /
    • pp.5-10
    • /
    • 1994
  • It is obtained the general expessions of the numerical method are applied for the TEM-mode analysis of multu-layer multi-coupled microstrip lines, In this paper, coupled microstrip are replaced by three-coupled microstrip lines in special aplications. Three-layer versions of three-coupled microstrip lines are specially attactive because of the additional flexibilities offered by three-layer configuration. This structure can be used for obtaining large capacitance and preventing coupling among microstrip lines in filter and coupler. Sappihre is chosen for anisotropic substrates material. The permittivity parallel to the optical axis is higher than the permittivity in the plane perpendicular to this axis.

  • PDF

Fault Location Estimation Algorithm of the parallel transmission lines using a variable data window method (가변 데이터 윈도우 기법을 이용한 병행 2회선 송전선 고장점 추정 알고리즘)

  • Jung, Ho-Sung;Yoon, Chang-Dae;Lee, Seung-Youn;Shin, Myong-Chul
    • Proceedings of the KIEE Conference
    • /
    • 2003.11a
    • /
    • pp.266-268
    • /
    • 2003
  • This paper proposes the Fault Location Estimation Algorithm in the parallel transmission lines. These algorithm uses a variable data window method based on least square error method to estimate fault impedance quickly. And it selects the optimal equation according to the operation situation and usable fault data for minimizing the fault estimation error effected by the zero sequence mutual coupling. After simulation result, we can see that these algorithm estimates fault location more rapidly and exactly.

  • PDF

Design and fabrication of a novel multilayer bandpass filter with high-order harmonics suppression using parallel coupled microstrip filter

  • Fathi, Esmaeil;Setoudeh, Farbod;Tavakoli, Mohammad Bagher
    • ETRI Journal
    • /
    • v.44 no.2
    • /
    • pp.260-273
    • /
    • 2022
  • This study presents a novel multilayer structure of parallel coupled-line bandpass filtercentered at 2.42 GHz with a fractional bandwidth value of approximately 19.4%. The designed filter can suppress harmonics with an appropriate frequency response by incorporating different techniques based on the multilayer technique. A combination of different techniques such as radial microstrip stubs and defected ground structure (DGS) and defected microstrip structure techniques are employed to suppress harmonics up to 5f0. These techniques are used in two layers to suppress up to 5f0. In addition, in this study, the effects of different parameters, such as the width of slot-line DGS, the angle of diagonal line slots in the upper layer, and the air gap between the two layers on the filter performance, are investigated. To verify the correct circuit operation, the designed filter is implemented and tested. The measurement results of the proposed filter are compared with the simulation results.