by Chuck Moseley, Inmarsat
Utility network management is complex. When severe weather or natural disasters hit, temporary or permanent damage can occur to the grid. It is estimated that more than 80 percent of network faults can be attributed to short-term “transients” in supply from disrupted power lines. To combat this, utility companies segment their distribution networks to isolate faults to as small a part of the grid as practical.
These segments, traditionally, were controlled by breakers installed at key points in the network. Breakers can respond only to significant power surges, however. In addition, they are typically installed only at substations. This means resilience is less than optimal. Reclosers eliminate these shortcomings because they enable utilities to manage and monitor their network in a more efficient manner before substations can be affected. They can be placed at strategic locations throughout the control network, allowing damage to be isolated and power re-routed before a substation is affected.
To function optimally, reclosers need an always-available, real-time connectivity solution that allows instant control in cases of outage or disruption to power lines. The reclosers can be triggered remotely and also can provide data back to the operations center, enabling utilities to prioritize restoration activities, reduce customer outage time, decrease revenue impacts from outages and minimize the potential for cascading infrastructure damage.
Ergon Energy, which is owned by the government of Queensland, Australia, distributes electricity to about 720,000 customers across Queensland. There are two sides to the utility-the side that builds and maintains the electricity distribution network and the retail side that sells electricity to residential and business customers. As an electricity retailer, Ergon Energy Retail sells electricity and provides customer service and support.
The network part of Ergon Energy builds and maintains the electricity distribution network for regional Queensland. It is, in essence, the “poles and wires” company. Its infrastructure covers 97 percent of the state of Queensland-more than a million square kilometers. Its distribution network covers some of the most rural parts of Australia, requiring 160,000 kilometers of power lines and more than 1 million power poles.
Ergon Energy has installed hundreds of reclosers throughout its network, with a significant number operating in the most isolated parts of the state, areas in which traditional connectivity methods, such as cellular and terrestrial, are limited or not available. Its requirement for remote connectivity was a single, ubiquitous, reliable network that was impervious to natural disasters and weather events, and could provide a high level of security.
Ergon tasked its subsidiary telecommunications carrier, Nexium Telecommunications, to seek out a supplier. Nexium Telecommunications selected Inmarsat’s BGAN m2M service to meet those needs. The satellite and ground network provides a seamless, easy to integrate, real-time, IP-based connectivity service, to remotely monitor, control and manage Ergon’s network.
The Wideye Ranger BGAN m2M terminal is a single-piece terminal that can be pole mounted. Because it has an IP66 water and dust resistance rating, it is an ideal solution for long-term, unmanned installation in remote areas.
Ergon Energy initially deployed 100 terminals quickly and efficiently, with no need for specialist installers or training. These 100 terminals allowed the utility to rapidly increase its connectivity to various distribution automation devices and sites. Each recloser uses between 5 MB and 15 MB of data per month in real time. BGAN m2M’s pooled data plan allows Ergon Energy complete budget control for its communications needs, because each terminal draws from a shared data pool.
“The Inmarsat BGAN m2M service has given us access to parts of our distribution network that had remained out of bounds when it comes to remote monitoring and control,” said Sanjeewa Athuraliya, senior telecommunications architect, Ergon Energy. “We chose Inmarsat for its reliability. Monitoring and controlling a power grid needs a real-time, always available flow of information and we’re happy to say Inmarsat’s service has been extremely reliable.”
BGAN m2M provided the reliability, cost effectiveness, security and ease of use that Ergon Energy needed to automate and monitor its distribution network. In addition, the operational lifetime of the service should run well into the 2020s.
Chuck Moseley is director, Internet of Everything, at Inmarsat. He joined Inmarsat in 2003 with more than 18 years’ experience in communications. He is responsible for Inmarsat’s portfolio of m2M products and services worldwide. Prior to this role, he managed all North American SCADA communications customers and projects for Stratos (now part of Inmarsat).