Smart Sensing Power Cable Monitoring
Underground Infrastructure, once installed, needs to stand the test of time. In some cases, data cables, wires, and power transmission lines can be expected to have an operating life from a few decades up to almost a century without the possibility of a visual inspection.
Monitoring for wear, damage, or corrosion of the cable is extremely difficult and often power failure or data outage is the first sign of a problem. Often, these cables are installed in areas that have multiple uses by various stakeholders and in the event of a failure can be logistically difficult and expensive to access for repair.
Learn about the different applications we work in:
How it Works: Sensing Methods
HAWK's Praetorian Fiber Optic Sensing System can monitor Power Cables using optical fiber Distributed Temperature Sensors DTS. The optical fiber cable may either be installed near the power cable or embedded within the power cable itself. In recent years, the technology to reliably carry out Distributed Acoustic Sensing has also been widely reported. Distributed Acoustic Sensing (DAS) technology based on coherent Rayleigh backscatter in optical fiber resembles a vast number of "microphones" using simple passive glass fiber as a sensor over long distances and has been a subject of significant interest.
The smart sensing power cable monitoring system utilizes several different sensing methods, making it possible to observe events in several physically independent ways. The power cable monitoring system is resistant to taking a given reading and giving a false alarm, due to the requirement for multiple physical effects to simultaneously occur at the same location to signify an event and trigger an alarm.
How it Works: Monitoring
Through a combination of distributed vibration, temperature, and strain monitoring, it is possible to determine multitudes of different physical events along a cable, including but not limited to:
- Detection of partial discharge
- Detection of hot spots
- Early alert of third-party intrusion
- Conductor break detection
- Ground condition assessment
- Prevention of arc flash events from conductor contact
- Detection of optical Loss
- Detection of Fiber Break
- Detection of pit or trench lid being opened
- Determination of network operational status (thermal loading)
- The System also has Geo-tags alarms, allowing security or maintenance teams to be able to respond immediately.
Frequently Asked Questions
Time of Flight. Locations of events are able to be accurately determined by a method called time of flight. The amount of time from sending the laser pulse to receiving a return signal is recorded. Due to the internal properties of a fiber optic core, the speed of light through a fiber is consistent at approximately two thirds of the speed of light through a vacuum (around 400μs for a 40km (25 miles) round trip). As this is consistent, the return time can be used to calculate a distance on the fiber.
Often the primary way of preventing damage to buried assets is to prevent them being struck and damage by third parties. As significant excavations are generally required to unearth buried assets due to their depth of cover the process of excavation takes sufficient time that a warning provided quickly enough can give an operator enough time to alert the third party to the dangers below them. Different digging events generate different signals which are picked up by the monitored fiber that are either part of or buried alongside the asset.
No, it requires no additional field infrastructure such as power or communications
Because Fiber Optic Technology provides a solution that is preventative rather then reactive