• Title/Summary/Keyword: Electrical fault

Search Result 3,416, Processing Time 0.026 seconds

Diagnosis of Poor Contact Fault in the Power Cable Using SSTDR (SSTDR을 이용한 케이블의 접촉 불량 고장 진단)

  • Kim, Taek-Hee;Jeon, Jeong-Chay
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.65 no.8
    • /
    • pp.1442-1449
    • /
    • 2016
  • This paper proposes a diagnosis to detecting poor contact fault and fault location. Electrical fire by poor contact fault of power cable occupied a large proportion in the total electrical installations. The proposed method has an object to prevent electrical fault in advance. But detecting poor contact fault is difficult to detect fault type and fault location by using conventional reflectometry due to faults generated intermittently and repeatedly on the time change. Therefore, in this paper poor contact fault and fault conditions were defined. System generating poor contact fault produced for the experimental setup. SSTDR and algorithm of reference signal elimination heighten performance detecting poor contact fault on live power cable. The diagnosis methods of signal process and analysis of reflected signal was proposed for detecting poor contact fault and fault location. The poor contact fault and location had been detected through proposed diagnosis methods. The fault location and error rate of detection were verified detecting accuracy by experiment results.

Development of Portable Cable Fault Detection System with Automatic Fault Distinction and Distance Measurement (자동 고장 판별 및 거리 측정 기능을 갖는 휴대용 케이블 고장 검출 장치 개발)

  • Kim, Jae-Jin;Jeon, Jeong-Chay
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.65 no.10
    • /
    • pp.1774-1779
    • /
    • 2016
  • This paper proposes a portable cable fault detection system with automatic fault distinction and distance measurement using time-frequency correlation and reference signal elimination method and automatic fault classification algorithm in order to have more accurate fault determination and location detection than conventional time domain refelectometry (TDR) system despite increased signal attenuation due to the long distance to cable fault location. The performance of the developed system method was validated via an experiment in the test field constructed for the standardized performance test of power cable fault location equipments. The performance evaluation showed that accuracy of the developed system is less than 1.34%. Also, an error of automatic fault type and location by detection of phase and peak value through elimination of the reference signal and normalization of correlation coefficient and automatic fault classification algorithm not occurred.

An Improved Algorithm of Fault Indicator Generation of FRTU in Distribution Automation System (배전자동화시스템에서 전류방향성을 이용한 단말장치의 고장표시 오류 개선 방법)

  • Seo, Jung-Soo;Kim, Hyung-Seung;Lim, Seong-Il;Choi, Myeon-Song;Lee, Seung-Jae
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.63 no.10
    • /
    • pp.1354-1363
    • /
    • 2014
  • In this paper, an improved method of fault indicator generation algorithm in FRTUs is proposed for the present Distribution Automation System. In order to find fault area, correct FI information should be generated. But when a single line-to-ground fault occurs, FI information is generated in downside of the fault in some circumstance because existing FI algorithm considers only magnitude. It is found that the upside fault current direction if different from the downside fault current direction. Therefore, in order to prevent to generate the wrong fault indication information for FRTU at the downside of the fault, an improved fault indication generation method is developed. Not only the basic conditions are taken into account, but also the directions from the angle difference between zero and positive sequence currents are considered to generated the fault indication information. In case study, the proposed method has been testified and shown the reasonability in generating correct the fault indication information, for many kinds of faults according to conditions.

Analysis on Current Limiting Characteristics of Transformer Type SFCL with Additionally Coupled Circuit

  • Lim, Seung-Taek;Ko, Seok-Cheol;Lim, Sung-Hun
    • Journal of Electrical Engineering and Technology
    • /
    • v.13 no.2
    • /
    • pp.533-539
    • /
    • 2018
  • In this paper, the transformer type superconducting fault current limiter (SFCL) with additionally coupled circuit was suggested and its peak fault current limiting characteristics due to the fault condition to affect the fault current were analyzed through the fault current limiting tests. The suggested transformer type SFCL is basically identical to the previous transformer type SFCL except for the additional coupled circuit. The additional coupled circuit, which consists of the magnetically coupled winding to the primary and the secondary windings together with another superconducting element and is connected in parallel with the secondary winding of the transformer type SFCL, is contributed to the peak fault current limiting operation for the larger transient fault current directly after the fault occurrence. To confirm the fault current limiting operation of the suggested SFCL, the fault current limiting tests of the suggested SFCL were performed and its effective peak fault current limiting characteristics were analyzed through the analysis on the electrical equivalent circuit.

A Decision Method for the Optimal Insertion Resistance of a Superconducting Fault Current Limiter with Reduction of an Asymmetric Fault Current (비대칭 고장전류 저감 기능을 갖는 초전도 한류기의 최적 저항 결정 방안)

  • Kim, Chang-Hwan;Kim, Kyu-Ho;Rhee, Sang-Bong
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.64 no.1
    • /
    • pp.57-63
    • /
    • 2015
  • Fault currents characteristics contain decaying DC offset. First cycle peak value of fault currents is higher than steady-state fault current value. These characteristics can affect the operation of protective device. To reduce the asymmetric fault current, the method using a series connection of two hybrid-type Superconducting Fault Current Limiter(SFCL) components, an auxiliary SFCL and a main SFCL, has been proposed. The auxiliary SFCL limits the first half cycle fault current, while main SFCL limits the steady state fault currents. This paper proposed a decision method of the optimal insertion resistance of auxiliary and main SFCL components. To verify the effectiveness of proposed scheme, the various simulations are performed by using Electromagnetic Transient Program(EMTP).

A Study on Digital Fault Locator for Transmission Line (송전선로용 디지털 고장점 표정장치에 관한 연구)

  • Lee, Kyung-Min;Park, Chul-Won
    • The Transactions of the Korean Institute of Electrical Engineers P
    • /
    • v.64 no.4
    • /
    • pp.291-296
    • /
    • 2015
  • Transmission line is exposed to a large area, and then faults are likely to occur than the other component of power system. When a fault occurs on a transmission line, fault locator helps fast recovery of power supply on power system. This paper deals with the design of a digital fault locator for improvement accuracy of the fault distance estimation and a fault occurrence position for transmission line. The algorithm of a fault locator uses a DC offset removal filter and DFT filter. The algorithm utilizes a fault data of GPS time synchronized. The computed fault information is transmitted to the other side substation through communication. The digital fault locator includes MPU module, ADPU module, SIU module, and a power module. The MMI firmware and software of the fault locator was implemented.

Protection for a Wind Turbine Generator in a Large Wind Farm

  • Zheng, Tai-Ying;Kim, Yeon-Hee;Kang, Yong-Cheol
    • Journal of Electrical Engineering and Technology
    • /
    • v.6 no.4
    • /
    • pp.466-473
    • /
    • 2011
  • This paper proposes a protection algorithm for a wind turbine generator (WTG) in a large wind farm. To minimize the outage section, a protection relay for a WTG should operate instantaneously for an internal fault or a connected feeder fault, whereas the relay should not operate for an internal fault of another WTG connected to the same feeder or an adjacent feeder fault. In addition, the relay should operate with a delay for an inter-tie fault or a grid fault. An internal fault of another WTG connected to the same feeder or an adjacent feeder fault, where the relay should not operate, is determined based on the magnitude of the positive sequence current. To differentiate an internal fault or a connected feeder fault from an inter-tie fault or a grid fault, the phase angle of the negative sequence current is used to distinguish a fault type. The magnitude of the positive sequence current is then used to decide either instantaneous operation or delayed operation. The performance of the proposed algorithm is verified under various fault conditions with EMTP-RV generated data. The results indicate that the algorithm can successfully distinguish instantaneous operation, delayed operation, or non-operation depending on fault positions and types.

A Novel Fault Location Scheme on Korean Electric Railway System Using the 9-Conductor Representation

  • Lee, Chang-Mu;Lee, Han-Sang;Yoon, Dong-Hee;Lee, Han-Min;Song, Ji-Young;Jang, Gil-Soo;Han, Byung-Moon
    • Journal of Electrical Engineering and Technology
    • /
    • v.5 no.2
    • /
    • pp.220-227
    • /
    • 2010
  • This paper presents a novel fault location scheme on Korean AC electric railway systems. On AC railway system, because of long distance, 40[km] or above, between two railway substations, a fault location technique is very important. Since the fault current flows through the catenary system, it must be modeled exactly to analyze the fault current magnitude and fault location. In this paper, suggesting the novel scheme of fault location, a 9-conductor modeling technique including boost wires and impedance bonds is introduced based on the characteristics of Korean AC electric railway. After obtaining a 9-conductor modeling, the railway system is constructed for computer simulation by using PSCAD/EMTDC. By case studies, we can verify superiority of a new fault location scheme and propose a powerful model for fault analysis on electric railway systems.

Fault Location for Incomplete-Journey Double-Circuit Transmission Lines on Same Tower Based on Identification of Fault Branch

  • Wang, Shoupeng;Zhao, Dongmei;Shang, Liqun
    • Journal of Electrical Engineering and Technology
    • /
    • v.12 no.5
    • /
    • pp.1754-1763
    • /
    • 2017
  • This paper analyses the characteristics of incomplete-journey double-circuit transmission lines on the same tower formed by single-circuit lines and double-circuit lines, and then presents a fault location algorithm based on identification of fault branch. With the relationship between the three-phase system and the double-circuit line system, a phase-mode transformation matrix for double-circuit lines can be derived. Based on the derived matrix, the double-circuit lines with faults can be decoupled, and then the fault location for an incomplete-journey double-circuit line is achieved by using modal components in the mode domain. The algorithm is divided into two steps. Firstly, the fault branch is identified by comparing the relationships of voltage amplitudes at the bonding point. Then the fault location, on the basis of the identification result, is calculated by using a two-terminal method, and only the fault distance of the actual fault branch can be obtained. There is no limit on synchronization of each terminal sampling data. The results of ATP-EMTP simulation show that the proposed algorithm can be applied within the entire line and can accurately locate faults in different fault types, fault resistances, and fault distances.

Analysis of Transient Characteristics of a SFCL Applied Into Third-winding Transformer in a Single Line-to-ground Fault (1선 지락 사고 시 3 권선 변압기에 적용된 초전도 한류기의 동작 특성 분석)

  • Choi, Hye-Won;Choi, Hyo-Sang;Jung, Byung-Ik
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.62 no.7
    • /
    • pp.1033-1037
    • /
    • 2013
  • Coercion transformer is commonly used in the electrical grid which in three phase of distribution system. The accident of the electrical grid is divided into a single, a double, a third line-to-ground faults and a double, a third line-to-line faults. A single line-to-ground fault accounts for nearly 75[%] among them. In this research, when a Superconducting Fault Current Limiters (SFCL) was applied to the three phase power system, operation in a single line-to-ground fault and limiting characteristics of fault current according to turns ratio of third winding were analyzed. When a single line-to-ground fault happened, secondary winding's circuit was open. Then third winding's circuit with a SFCL was closed. So fault current was limited by diverted circuit. At this time, we could find out that size of the limited fault current could be changed according to third winding rate. We confirmed that limiting operation of the fault current was carried out within one-period. These results will be utilized in adjusting the size of the SFCL.