New grid applications such as metering and grid surveillance are capacity hungry. Aviat Networks explains more
The digitisation of utility operations is producing better grid monitoring through the installation of sensors along the distribution value chain.
Data is offering that visibility but where there is data there needs to be connectivity, and crucially capacity, to transmit information back to control centres in real or near real time.
New applications such as metering and corporate networking are low capacity individually. However, once aggregated, they become a large consumer of utility telecommunications bandwidth, explains Ronil Prasad, Director of Product and Regional Marketing at Aviat Networks.
In an Engerati webinar ‘Enabling a smart grid: How to prioritise data traffic for faster utility networks’, Prasad explains how the moving of time-division multiplexing networks to packed-based transport is forcing utilities to assess their mission-critical data applications and design a network around them.
“Utilities will no longer have the luxury of being able to sort through their services and drop some to make room for more critical applications," he says.
While critical services such as voice, teleprotection and SCADA will continue to rank uppermost for their share of utility telecom networks, there are four Internet-Protocol enabled services that are also demanding their stake of bandwidth.
Security is the biggest driver of capacity for utility data networks, explains Prasad.
In North America, security and more specifically surveillance video have become the largest consumer of bandwidth.
Cameras deployed for substation surveillance are high definition with pan-tilt-zoom functionality allowing 360-degree view capabilities. "Each camera individually can consume as much as 6MB/s of traffic and we are seeing a minimum of two to three cameras per substation covering entry and exit points and surrounding areas," explains Prasad.
Meanwhile, control sites can have as many as 10-12 cameras. "As we move forward, this will continue to be the largest consumer of bandwidth in the network," he confirms.
The data applications of metering, fault reporting and event analysis are also increasingly high priority and when combined, demand significant network capacity, says Prasad. A conservative estimate of consumption per site, based on data points from North American utilities, is 10 Mbps but that can easily grow to about 20 to 25 Mbps, he confirms.
Another capacity hungry and increasingly vital service is corporate networking covering remote field personnel, office employees and the addition of new greenfield sites.
"Utilities often find it's more convenient to have these services riding on a fixed private network than to use a public network or to create a new separate network for this traffic," explains Prasad. "These include standard local area network services, internet connectivity, and connectivity to link substations together."
There are also cases where fixed corporate services might not be possible so utilities deploy LTE for mobile broadband services through a partnership with a carrier. Alternatively, they can adopt a hybrid approach of part private and some offloading to a carrier network, he explains.
The fourth new grid application that is representing a challenge to existing utility data bandwidth is the deployment of phasor measurement units (PMUs).
These sensors that give utilities additional information on network performance by tracking power quality are doing so at high resolution by streaming real-time data, explains Prasad.
"PMUs are being considered next-generation SCADA because of the granularity that they offer," he says.
But the difference in bandwidth consumption is significant. While SCADA collects one sample every two to four seconds, PMUs transmit 10-60 samples every second in real time.
Prasad says as the uptake of PMUs increases on grid networks, this is another service where bandwidth requirement "can scale very steeply".
Watch Ronil Prasad's full webinar presentation to learn how to dimension traffic loading, calculate network capacity as well as assess the best telecommunication method for high priority utility applications.