LIRA® TECHNOLOGY
Cable integrity is vital to the safe and efficient operation of any facility - plant, factory, wind farm, oil field, transmission and distribution network, even more so when a facility should operate long-term. Despite their importance, cables typically receive little attention – they are considered passive, long- lived components that are very reliable. However, cable failures have caused facility shutdowns, safety concerns, loss of revenue and damage to reputation. In some cases, it costs human lives. Performance and safety concerns demand proactive and preventative approaches to cable integrity and reliability. This is where Wirescan Digital comes in. It is a cable health and aging management program which anticipates and addresses cable aging issues (including residual life assessment) helps reduce maintenance costs, avoids unscheduled shutdowns and repairs, incorporates industry best practices and addresses regulatory requirements.
As everything in the Wirescan portfolio, Wirescan Digital is based on our patented the LIRA® Technology.
This is the backbone and heart of everything Wirescan does.
A bit of history
The LIRA Technology was born in Norway in the middle of winter in the Institute for Energy Technology (IFE) in Halden in the early 2000’s to its “father” Paolo Franco Fantoni. At this time, there was an acute need to create and develop a non-destructive test and condition assessment method for cables in nuclear power plants. Driven by his passion and creativity Paolo moved from the warm Genova to the snow-chilled Norway to find a solution to this need. It is there he created and brought this unique technology to life. Today, 16 years later, this ground-breaking innovation is a well-known, established technology, proven by impressive track-record from all industries on all continents, wherever there are cables. It is as unique as it was then, if not more.
Many cable condition assessment technologies in the market today are still potential destructive, and cannot be regarded as an alternative test method for cables where cable destruction leads to time consuming and cost driving maintenance operations. Other technologies are non-destructive, but provide too little information and security related to the continued operation of the relevant cable.
LIRA Technology covers all of it and more. It is the most comprehensive cable assessment and monitoring technology in the market to date.
What is LIRA® Technology
The LIRA (Line Resonance Analysis) technology is a cable condition assessment, cable fault location and cable aging management system that works in frequency domain through advanced proprietary algorithms. LIRA is based on the Transmission Line Theory. It calculates and analyses the complex line impedance as a function of the applied signal for a wide frequency band. It detects and locates changes in the cable impedance and makes it possible to perform fault location and cable condition monitoring on I&C, low, medium and high voltage cables even in inaccessible and challenging environments.
The input impedance response is related to wave reflection and can be measured in the LIRA
hardware over the required frequency range. The cable termination, length, impedance, and
other electrical characteristics give a unique signature of input impedance amplitude and phase,
that can be used to determine the condition of the cable. Input impedance spectrum,
amplitude/phase, can be affected by any local and/or global physical and electrical cable
property changes such as insulation damages, splices, or shield defects.
How does it work?
LIRA measures impedance irregularities .... between any two metallic conductors
• conductor – conductor
• conductor – screen
• conductor – steel armour
• screen – steel armour
• conductor – lead sheath
• conductor – steel armour
• lead sheath – steel armour
When Wirescan proprietary data acquisition equipment is connected to the cable, it injects a low voltage sweep signal of only 5V into the cable. This is entirely harmless for a cable.
The signal travels through the cable, reflects from the other end and brings back a set of data which our proprietary algorithms translate into information valuable for cable health assessment, fault detection and monitoring.
What does the LIRA® Technology tell you?
LIRA is a highly sensitive technology. One LIRA Measurement generates more than ten results.
LIRA® Technology Results
Through changes in the cable electrical parameters LIRA detects and locates local degradations in the cable, which is specific to certain sections of the cable and caused by joints and splices, mechanical stress and damages, by heat-induced oxidation, radiation, water intrusion, over bending, mechanical impacts, fatigue, etc.
At the same time, it also detects global degradation in the cable (aging indicator), which is applicable for the entire cable, and caused by general aging, due to external and internal environmental conditions. It allows to evaluate severity of a damage and make conclusions on potential character and cause of the detected event.
LIRA detects multiple irregularities/changes on the same cable from one measurement.
When fault is identified the accuracy of its localization is between 0,1 and 0.3% of a cable length. When you measure from one end, LIRA allows you to see impedance changes at the far end connection.
Data acquisition is non-invasive, quick regardless whether it is done manually on de-energized cables or automatically on energized cables. It also allows for remote control.
LIRA® Technology Roundup
Do you want to dive in deeper and learn more of the LIRA Technology. Click here for a selection of White papers and articles.