Cable Fault Monitoring and Indication: A Review
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paper_title: Detection of Incipient Faults in Distribution Underground Cables

paper_content:

The incipient faults in underground cables are largely caused by voids in cable insulations or defects in splices or other accessories. This type of fault would repeatedly occur and subsequently develop to a permanent fault sooner or later after its first occurrence. Two algorithms are presented to detect and classify the incipient faults in underground cables at the distribution voltage levels. Based on the methodology of wavelet analysis, one algorithm is to detect the fault-induced transients, and therefore identify the incipient faults. Based on the analysis of the superimposed fault current and negative sequence current in the time domain, the other algorithm is particularly suitable to detect the single-line-to-ground (SLG) incipient faults, which are mostly occurring in underground cables. Both methods are designed to be applied in real systems. Hence, to verify the effectiveness and functionalities of the proposed schemes, different fault conditions, various system configurations, and real field cases are examined and other transients caused by permanent fault, capacitor switching, load changing, etc., are studied as well.
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paper_title: Ageing mechanisms and diagnostics for power cables - an overview

paper_content:

This paper describes briefly the main ageing and failure mechanisms and will indicate the advantages and limitations of the diagnostic tests available for the different insulation systems used in distribution and transmission cable systems. SC21 of CIGRE has addressed the subject of ageing factors and diagnostics of cable systems and has published three reports covering both fluid-filled and extruded cables. The reports describe ageing factors and several diagnostic methods, their purpose, and guidelines for use.
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paper_title: Computerized underground cable fault location expertise

paper_content:

Power Technologies, Inc. (PTI) developed an expert system and on-line advisor for the Electric Power Research Institute (EPRI). The system, FAULT, provides guidance for field crews to diagnose a cable failure, recommend applicable fault location techniques, and trouble-shoot resulting difficulties which occur during the process of locating underground cable faults on transmission and distribution cable systems. The fault location methods which were identified during development of the expert system are presented in this paper, along with utility statistics from a survey on underground cable fault location. >
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paper_title: Real-time expert system for fault location on high voltage underground distribution cables

paper_content:

To ensure minimum loss of system security and revenue it is essential that faults on underground cable systems be located and repaired rapidly. Currently in the UK, the impulse current method is used to prelocate faults, prior to using acoustic methods to pinpoint the fault location. The impulse current method is heavily dependent on the engineer's knowledge and experience in recognising/interpreting the transient waveforms produced by the fault. The development of a prototype real-time expert system and for the prelocation of cable faults is described. Results from the prototype demonstrate the feasibility and benefits of the expert system as an aid for the diagnosis and location of faults on underground cable systems. >
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paper_title: Impedance based fault location method for phase to phase and three phase faults in transmission systems

paper_content:

This paper presents a new impedance based fault location method in the case of phase to phase and three phase faults. This method utilized the measured impedance by distance relay and super imposed current factor, which is the ratio of post-fault current to super imposed current, to discriminate the fault position on the line. This method is robust against the fault resistance. The presented method only uses the measured impedance by distance relay, the super imposed current factor and few data which could be achieved through the SCADA based databases. (5 pages)
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paper_title: Automatic fault location for underground low voltage distribution networks

paper_content:

Summary form only given, as follows. This paper describes an automatic fault location technique for permanent faults in underground low voltage distribution networks (ULVDNs). It uses signals from an existing time domain reflectometry (TDR) instrument. It preprocesses TDR signals to eliminate reflections due to single-phase tee-offs, and to locate 3-phase open or short circuit faults and also uses adaptive filtering to compare the TDR signals to locate faults In essence, the procedure minimises the interpretation skill required from a user of a typical TDR based fault location instrument. The relative performance of the system is demonstrated using real field data.
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paper_title: Impedance based fault location method for phase to phase and three phase faults in transmission systems

paper_content:

This paper presents a new impedance based fault location method in the case of phase to phase and three phase faults. This method utilized the measured impedance by distance relay and super imposed current factor, which is the ratio of post-fault current to super imposed current, to discriminate the fault position on the line. This method is robust against the fault resistance. The presented method only uses the measured impedance by distance relay, the super imposed current factor and few data which could be achieved through the SCADA based databases. (5 pages)
---
paper_title: Computerized underground cable fault location expertise

paper_content:

Power Technologies, Inc. (PTI) developed an expert system and on-line advisor for the Electric Power Research Institute (EPRI). The system, FAULT, provides guidance for field crews to diagnose a cable failure, recommend applicable fault location techniques, and trouble-shoot resulting difficulties which occur during the process of locating underground cable faults on transmission and distribution cable systems. The fault location methods which were identified during development of the expert system are presented in this paper, along with utility statistics from a survey on underground cable fault location. >
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Title: Cable Fault Monitoring and Indication: A Review

Section 1: Introduction
Description 1: Introduce the importance of accurate fault location in power systems, explaining the challenges and need for efficient fault location methods in transmission and underground power cable networks.

Section 2: Types of Cable Faults
Description 2: Describe various types of cable faults, including open conductor faults, shorted faults, and high impedance faults.

Section 3: Open Conductor Fault
Description 3: Explain what an open conductor fault is and provide details on its characteristics and implications.

Section 4: Shorted Fault
Description 4: Describe the characteristics of a shorted fault, emphasizing the low resistance path to ground.

Section 5: High Impedance Fault
Description 5: Discuss high impedance faults, detailing how they exhibit a high resistive path to ground and potential non-linear resistive characteristics.

Section 6: Types of Faults Detection
Description 6: Outline the different methods used to detect faults in power lines and cables, highlighting their suitability for each type of fault.

Section 7: A-Frame Method
Description 7: Provide an in-depth explanation of the A-Frame method, including its procedure, advantages, and limitations.

Section 8: Thumper Method
Description 8: Discuss the Thumper method, detailing its use of high voltage surges to locate faults and the challenges it presents.

Section 9: Time Domain Reflectometry (TDR)
Description 9: Describe the Time Domain Reflectometry (TDR) method, explaining its process and how it determines the fault location using signal reflections.

Section 10: Bridge Method
Description 10: Explain the Bridge method for locating faults, including the principles of modified Wheatstone circuits and specific bridge techniques like Murray and Glaser bridges.

Section 11: Conclusions
Description 11: Summarize the importance of fault location in power systems, reviewing the methods discussed and emphasizing the need for immediate fault indication and accurate location techniques.