Distributed electro-mechanical sensing (DES)
Synaptec’s unique photonic instrumentation platform allows wide-area sensing networks to be built at low cost by deploying multiple passive sensors throughout existing, under-utilised fibre networks and making measurements available at a central location.
Passive sensor networks
Synaptec’s patented optical sensing technology allows measurements of voltage or current to be deployed at any location on a power system, requiring only access to the existing singlemode fibre network in the vicinity. None of the other supporting infrastructure associated with traditional measurement techniques is required (e.g. power supplies, active telecoms, and GPS receivers). This vastly reduces the cost per measurement across a power network, and allows sensors to be deployed in locations at which they would previously have been considered too remote, bulky, or costly.
The same technology allows precise, point measurement of mechanical and environmental parameters – such as strain, line sag, vibration, and temperature – to be integrated into the same fibre sensing network as the electrical measurements, forming a holistic sensing platform for instrumentation and monitoring of critical power networks and assets.
At each location, a sensor may be ‘plugged in’ to the existing fibre network via singlemode fibre splicing; a standard technique familiar to approved installers across the power and telecoms sectors. Connection to the electrical system is made using industry-standard current and voltage transformers, and mechanical sensors are installed using non-disruptive mounting techniques. Measurement signals are encoded in optical wavelength (colour of light), making them immune to electromagnetic interference and inherently secure.
A single Synaptec Interrogator IED, typically installed in a substation, can monitor up to 30 sensors per fibre over distances of up to 60 km. The Interrogator is the only device in a Synaptec sensor network that requires power or time synchronisation. The Interrogator outputs measurement data and time-critical functions to secondary devices in industry-standard digital or analogue formats for real-time protection and monitoring applications, as well as to Synaptec’s Synthesis™ software dashboard for logging, live visualisation, and powerful analytics.
Synaptec’s sensor technology uniquely combines two proven technologies to achieve high-performance distributed measurements. A high-precision piezoelectric stack – which expands and contracts microscopically in response to an applied voltage – is used to convert the electrical signal into a proportional mechanical strain. Synaptec uses the same piezoelectric elements used by NASA’s mars rovers, which have undergone significant stress testing, proving an operational lifetime of many decades.
The second key component is a fibre Bragg grating (FBG), a common form of optical strain gauge used throughout the world in challenging sectors including structural monitoring, telecommunications, aerospace, and military. The FBG is used to convert the strain imparted by the piezoelectric stack into an optical signal: when illuminated with a broadband light source, an FBG will reflect at a particular well-defined wavelength (much like a microscopic mirror) that is defined by the strain applied to the FBG. Like a mirror, this technique is completely passive and therefore immune to EMI, enabling sensors to be deployed at unprecedented distances from the central Interrogator unit in some of the most challenging and remote locations in the world.
By combining these techniques, Synaptec is able to measure both electrical and mechanical properties over unprecedented distances without requiring any supporting infrastructure to be installed at the remote measurement locations.