Issue link: https://fhpublishing.uberflip.com/i/672433
NETWORK / 26 / MAY 2016 Rigorous testing is one of DNO's key weapons in the battle against expensive, and potentially fatal faults on the system Up in flames E lectricity distribution network operators are obliged to accommodate the ever increasing amount of distributed generation pushing to connect to their network as the UK looks to meet its carbon targets. But each new connection has the potential to compromise the smooth running and safety of the existing network, electricity testing equipment manufacturer Megger warns. The first issue arises from the need to push the UK's aging electricity infrastructure ever harder to accommodate new connections while avoiding costly reinforcement. Assets on the high voltage network, already highly stressed, are being worked further. For DNOs to ensure that safety is being maintained regular testing is essential. Similarly, at the other end of the spectrum, when limits are finally reached and new infrastructure is unavoidable, each new addition needs testing to ensure it has been installed correctly, and will not compromise the rest of the system. The same is true of each new renewable generation plant. All the while the electricity system is continuing to age and deteriorate, with DNOs keen for any data on the condition of their infrastructure. Megger is fully aware of the catastrophic consequences of failing to properly test the system. A fault in a medium- sized substation can easily result in fire -and when the oil that provides coolant within the system reaches the air – a massive explosion. This inevitably destroys the entire substation, an asset DNOs can ill afford to lose. Incidents on this level are a huge risk to public safety, with the potential for fatalities and fines to be handed down by Ofgem for safety failings. DNOs may be able to bypass the affected section without end consumers being aware of the problem, but a damaged substation will have to be replaced. Substations not only cost millions, but also cannot just be bought from the shelf. Each substation takes years to manufacture. Most faults in electrical equipment occur due to a failure in the insulation. No insulation material is perfect says Megger, and very high voltages particularly stress insulators, resulting in faults when lower voltages would not have caused problems. Testing insulation at high voltages is how Megger came into being – the name being an amalgamation of the Megaohm meter it designed in 1903 – but their capabilities now stretch right from power plant to plug in the energy system. The huge range of products are all manufactured in-house, and safety is not only the end goal of each product but is at the forefront of megger's mind during the manufacturing process. Safety features are built in to ensure the user's safety in potentially dangerous testing situations is never compromised. Beyond testing Megger also provides network companies with the opportunity to acquire data from their substations for analysis. Data acquisition is a key theme among network operators currently. SHEPD and SEPD launched a Network Innovation Allowance project in March this year specifically looking to test a range of devices for monitoring voltage and current data at 11Kv/415v secondary substations to help build a 'big picture' of the network. Currently most of these facilities are without any analytic capabilities. Megger is also involved in National Grid's Offgrid Substation Environment for the Acceleration of Innovative Technologies (OSEAIT) Network Innovation Competition project which aims to modify an existing 400kv substation into a field trial facility to enable networks to overcome the operational barriers associated with the implementation of innovative methods and technologies on the electricity network. While Megger has a good handle on testing, it adds its voice to the growing call that the approaching skills gap could have the potential to seriously disrupt the smooth running of the system, and cites education as the only way to combat it. With such valuable assets at risk, it is a call DNOs can ill- afford to ignore. KEY POINTS u Leader in insulation testing at high voltages u Products for testing from powerplant to plug u Manufacture in-house at site in Dover Network visited Megger's headquarters in Dover to hear about the importance of electrical testing and see the complete in-house manufacturing process of its products, from circuit board creation and transformer wiring right through to in-house safety checks. on site