Cable Fault Location Solutions for Long Submarine and Land Cable Systems
- May 29, 2020
- Posted by: Dominique
- Category: Cable Fault Location
With the increasing emergence of renewable energy, cable links are becoming longer and longer up to several hundred miles, such as from offshore wind developments or underground land transmission lines for the clean energy power grid. Depending on the fault type and breakdown voltage of the fault, traditional cable fault location systems do not have the necessary means to accurately locate the faults. In fact, during DC testing a tremendous amount of energy is stored within the cable, which when discharged, can destroy the test equipment and is a huge safety risk for the operating personnel. BAUR, with its long-standing tradition and experience in cable fault location, can develop tailor-made solutions for quickly and efficiently locating cable faults on extra long submarine and land cables.
Long submarine and land cables are phenomenal infrastructure investments. Any unexpected failure or downtime translates to hundreds of thousands or millions of dollars in losses to the cable operator. Long lengths of land cables with cross-bonding configurations cause difficulty in the interpretation of the measuring results due to multiple reflections. An increased time to locate the fault equates to higher downtime losses to the operator.
Submarine cable links can be damaged by ship anchors and fishing boat trawl nets. Particularly in deep-sea areas accurate location of these faults is extremely difficult. Most TDR-based cable fault location methods have an accuracy of ± 1%, based on the total cable length. For example, if there is a fault within a 350-mile submarine or land cable, the fault tolerance of the system would be 3.5 miles either side (7 miles total)! Without proper pinpointing measures (difficult in subsea environments) or expensive and time-consuming investigations on the seabed, large and costly cable segments would have to be cut.
The ideal investment for very long cable lengths is to have stationary cable fault location measurement systems be installed at both cable ends. The ability to measure from each cable end significantly improves the measuring accuracy. Access to accurate cable data and to reference points of known joints further improves the accuracy. Moreover, stationary equipment would mean immediate fault location can be conducted, reducing the overall downtime. The enormous time saving itself pays for the cable fault location equipment investment, even after just one cable fault. The adage “time is money” is particularly true in this case!
Custom Solutions From BAUR
BAUR offers a range of custom fault location systems for all types of extra long power cables:
- HVDC submarine cables (monopole and bipolar configurations)
- HVDC land transmission cables
- AC submarine cables
- AC land and submarine combination cables
- AC land transmission cables with cross bonding
Portable Instruments:
The Shirla is a lightweight and portable cable fault locator based on the measuring bridge principle according to Murray and Glaser. This instrument is particularly handy for its rapid transportation to the faulted cable. The Shirla can also be fitted as a specialized version with a long HV bridge cable for measuring extra-long submarine or land cables.
The IRG 4000 is a very powerful and software-driven time domain reflectometer capable of measuring cable lengths up to 1,000 km (621 miles). This instrument can be used for TDR fingerprinting and for quickly locating short circuit faults or cable cuts. Coupled together with a surge generator (thumper) this becomes a complete cable fault location system capable of various location methods.
Mobile Systems:
Mobile cable fault location systems are great for fault location on multiple cables, especially if fast transportation to the faulted cable is required. For this cable test vans are an ideal investment.
For when mobile systems are required in substations with many cable links, cable fault locators can be built on trolleys with optional lifting eye bolts for overhead cranes. These systems can be equipped with powerful DC sources with 32 kV or 70 kV test voltages, 3000 J output surge generators (thumpers), and powerful 90 A burn-down transformers. The system is completed with the powerful IRG 4000 time domain reflectometer, allowing a multiple method approach capable of fault locating very long lengths of cable.
Stationary Systems:
Stationary systems are ideal for cable systems that would have extremely high costs associated with power failure and where time is of the utmost importance. There is no time lost due to transportation and the system can be immediately deployed following a failure. Ideally both cable ends would be fitted with a stationary system to greatly improve the positional accuracy of the cable fault. As previously mentioned, downtime costs, which can amount to several hundreds of thousands of dollars or even millions, would be drastically reduced. The investment of 2 stationary cable fault location systems on either end of the cable would pay for itself after the first fault occurs.
The stationary systems can be mounted in containers that include powerful DC sources capable of up to 110 kV, 3000 J output surge generators (thumpers), 90 A burn-down transformers, and IRG 4000 time domain reflectometer for multiple fault location methods. The containers can be fitted with a partition to separate the operating compartment with the high voltage compartment.
If you would like to learn more, feel free to contact one of our sales managers at