Australian circuit breakers to protect UK distribution grid

British utility UK Power Networks is using Australian-developed circuit breakers to protect its distribution network. 

Siemens has received a 1.5 million euro (AU$2.23 m) order from UK Power Networks to equip parts of its overhead line system with a locally developed Australian innovation, Siemens’ Fusesaver technology. As part of the agreement, Siemens will supply 600 Fusesaver vacuum circuit breakers and 200 remote control units (RCU) to UK Power Networks. 

Siemens’ Australian innovation is exported to over 20 countries and is helping eliminate 80% of sustained electricity outages on rural networks. 

“This order is an important milestone in the development of the European market for the Fusesaver,” said Stephan May, CEO of Medium Voltage Systems at Siemens. “UK Power Networks is an important partner for us.” It is the largest order to date for Fusesavers in Europe and the first one from the UK.

Headquartered in London, UK Power Networks deliver electricity in the capital, south-east and east of England to approximately 8.2 million homes and businesses. The service area covers approximately 30,000 km². The vacuum circuit breakers will be installed directly on overhead cables to minimise the number of customers affected in the event of a fault. This is said to minimise installation and maintenance costs while significantly improving supply reliability and grid stability.

“The Fusesaver eliminates the number of maintenance deployments almost entirely,” said Matthew Corbridge, a network development engineer at UK Power Networks. He explained that UK Power Networks has an extensive overhead line system in eastern and south-eastern England, and there are a lot of spur lines in this system.

“In our continuing efforts to reduce the number of power cuts caused by a range of factors, we needed a cost-effective solution in order to ensure a reliable power supply for customers on the main lines. The Fusesaver meets these requirements with its highly flexible scalability and its easy installation.” 

The circuit breakers have helped save millions of hours of electricity outages in rural networks worldwide and, in the process, saved costs for providers, said Andrew Theodore, head of energy management at Siemens for Australia and New Zealand.

Distribution grids on the medium-voltage level can be installed both above and below ground. Many countries, such as the United States, Australia and the UK, distribute their medium-voltage electricity using mainly outdoor distribution grids. Siemens developed the Fusesaver vacuum circuit breaker to protect and improve the supply reliability and stability of these networks.

The circuit breaker weighs 5.5 kg and can be installed in series with existing fuses. If a temporary fault occurs, such as a lightning strike or a tree branch on the line, the vacuum circuit breaker upstream from the fuse opens and protects it from damage. Since a fuse cannot distinguish between temporary and continuous faults, it needlessly interrupts the circuit for a long period of time in 80% of cases. It can also completely replace the fuse, as in the UK Power Networks system. Temporary faults thus only lead to very short interruptions of the power supply. To avoid more extensive damage, the device interrupts continuous faults until the cause of the fault has been eliminated. It is equipped with a wireless communication interface, over which the control and measured data can be transmitted to a PC or the control desk. This establishes the prerequisites for a smart grid. 

Image supplied by Siemens