New computer software has emerged in the market that is able to visually represent the diffusion of energy into the surrounding environment.
Software packages now have the ability to “stress test” scenarios under electrical fault conditions. The technology builds a 3D virtual version of the system under study, creating a colour image site map similar to those used in thermal imaging in which different colours represent the voltage strength in a particular area or space.
This new current distribution, electromagnetic fields, grounding and soil structure analysis (CDEGS) software mathematically simulates the fault energy return current under the ground, to study above ground systems. The fault energy return current is the flow of electrons that short circuit to earth during some kind of fault - for example a lightning strike - and then ‘return’ to the source, such as the power station, generator or wind turbine that generated the power.
Modelling above ground systems is a relatively new concept, but the new software means designers can look at how much
energy will flow back to the source via the ground itself, and how much will travel down some other route, such as a buried cable or water pipe.
The system therefore allows designers to study a range of facilities including substations, pipelines and anything above ground that could suffer a lightning strike, and give asset owners and project managers greater knowledge and awareness of the risks on site, which in turn means they can choose the appropriate earthing solutions for their project - saving money and, potentially, saving lives.
“Increasingly, there isn’t anything that we touch or experience that hasn’t been modelled or simulated in some way - electrical assets are no different”
Ian Griffiths, GreyMatters
“Increasingly, there isn’t anything that we touch or experience that hasn’t been modelled or simulated in some way - electrical assets are no different,” explains Ian Griffiths, principle partner of GreyMatters, which is one of only four companies in Europe that are fully accredited and certified in the use of CDEGS technology. “It makes sense to turn something complicated into a visual map that everyone, regardless of their backgrounds, can understand - from the site supervisor to the consulting engineer/client and everyone in between.”
Griffiths says that CDEGS software can be used to model any project that includes high voltage energy, such as data centres, wind farms or tidal plants. GreyMatters is currently using the software for earthing and lightning protection studies and design at the new €130M (£102M) Terminal 3 at Julius Nyerere Airport in Dar es Salaam, Tanzania, being built by Bam International.
The earthing study uses the software’s scenario testing function to virtually test the earthing in various areas of the building if faults were to happen, to ensure that people inside the terminal would be safe. New earthing can be added virtually, so that improvements can be tested before they are built in reality. Similarly, lightning protection is tested so that the equipment can be installed in the best location on the terminal.
A key reason why this software has emerged in the industry is because 2010 saw changes to the code of practice for power system earthing above 1kV for developing energy facilities. This became enforceable in 2012 across the EU, with the standard explicitly recognising the role played by this specialised computer software in compliant design.
- Niall Cardwell works in research and development at Greymatters