Hawk Measurement Praetorian Fiber Optic Sensing Power Cable Monitoring

The Praetorian Fiber Optic Sensing System can monitor buried and unburied data cables, wires and power transmission lines. 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. These cables are typically installed in areas that have multiple uses by various stake holders and in the event of a failure can be logistically difficult and expensive to access for repair. The Praetorian Fiber Optic Sensing System can be installed either near the power cables or embedded within the power cable itself. It can monitor disturbances, identify manual and machine excavation, vehicle movement, ground condition assessment and detects hotspots. HAWK’s Fiber Optic Sensing System requires no additional field infrastructure such as power or communication and does not require maintenance or calibration after commissioning.

Principle of Operation:

Using a combination of Rayleigh backscatter, Brillouin backscatter and time of flight, Praetorian determines the presence, location, intensity and frequency of vibrations and temperature changes along an optical fiber in real time. These fibers can be integral to or laid with high voltage power transmission cables and operate as a comprehensive Power Cable Monitoring System (PCMS).

By monitoring both the temperature and vibration from the same system it is possible to detect and locate a wide range of faults detrimental to cable health including predictive detection capable of alerting operators of threats to a cable prior to failure.

How does it work?

Distributed Acoustic Sensing (DAS) continuously monitors Vibration, Sound and Acoustic Energy along the fiber using a process called Rayleigh Backscatter along the entire length of an optical fiber. Using a “time of flight” calculation on the laser pulse the position of any incoming signal can be determined to within a meter on up to 80 kilometres (50 miles) of fiber.

Distributed Temperature Sensing (DTS) and Distributed Strain Sensing (DSS) work in a similar way, but use a looped fiber within the sensing cable to detect both Temperature and Strain. The laser is sent down both sides of this loop and the interference pattern allows for Brillouin Backscattering to be measured revealing changes to Strain and Temperature within the fiber.

Praetorian has a built-in Field Programmable Gate Array (FPGA) which quickly records, processes and analyses the data collected by the system and detects and reports signals generated by problematic events within the environment.

Features:

What does Praetorian tell me?

Praetorian has a built in Human Machine Interface (HMI) and can be operated directly or connected to existing Control Systems (such as SCADA) via a digital communications protocol (Typically TCP/IP) and report:

• The location of the alarm
• The classification of the alarm
• The alarms longitude and latitude
• The intensity of the alarm
• A time and date stamp of the alarm
• And other detected conditions depending on the specific application